®
ErgoPlus, InLine Pave, NIVELTRONIC, NIVELTRONIC Plus, NAVITRONIC, NAVITRONIC Plus, RoadScan and V-TRONIC are registered Community Trademarks of JOSEPH VÖGELE AG, Ludwigshafen/Rhein, Germany. PCC is a registered German Trademark of JOSEPH VÖGELE AG, Ludwigshafen/Rhein, Germany. NIVELTRONIC Plus and NAVITRONIC Plus are trademarks registered in the US Patent and Trademark Office to JOSEPH VÖGELE AG, Ludwigshafen/Rhein, Germany. Legally binding claims cannot be derived from written information or pictures contained in this brochure. Pictures may include optional extras. We reserve the right of technical or design alterations.
2280299 EN/10.12
VÖGELE Booklet on Paving
Telephone: +49 (0)621 8105 0 Fax: +49 (0)621 8105 461 www.voegele.info
VÖGELE Booklet on Paving
JOSEPH VÖGELE AG Joseph-Vögele-Straße 1 67075 Ludwigshafen · Germany
[email protected]
FOREWORD Dear Reader, We are delighted to present you with our new Booklet on Paving. Following its great success in recent years, we have completely revised our Booklet and brought it right up-to-date. The chapters "Material Feeders", "Spray Technology" and "Two-layer Paving" are new additions due to the great advancements that have taken place in these technologies. As a result, our Booklet on Paving remains an indispensable work of reference for all paving professionals, trainees and students of road construction engineering. It contains the answers to innumerable questions on the subject of "road construction using paver technology from VÖGELE". We hope you enjoy reading and working with our Booklet! JOSEPH VÖGELE AG
Axel Fischer
Roland Schug
1
VÖGELE Booklet on Paving
contents
1.1 Differences between Construction Machinery and Pavers ............................... 1.2 Components of a Road Paver ............................................................................... 1.3 The Floating Screed Principle ............................................................................... 1.4 Theoretical Outline of the "Floating Screed Principle" without Grade and Slope Control ........................................................................ 1.5 Tracked Pavers and Wheeled Pavers . .................................................................. 1.6 VÖGELE Product Overview ................................................................................... 1.6.1 Paver Classification . ............................................................................................................ 1.7 Examples of Paver Applications ........................................................................... 1.7.1 Types of Paving ..................................................................................................................... 1.7.2 InLine Pave® / SprayJet Technology ................................................................................. 1.7.3 Paving Materials . ..................................................................................................................
13 14 18 20 22 22 24 26
2.5 2.6 2.6.1 2.6.2 2.6.3 2.7 2.7.1 2.7.1.1 2.7.1.2 2.7.2 2.8 2.9 2.9.1 2.9.2
2
Screed
29
3
2.1 2.2 2.2.1 2.2.2 2.2.3 2.2.4 2.2.5 2.3 2.3.1 2.3.2 2.3.3 2.3.4 2.4 2.4.1 2.4.2 2.4.3
General Differences between Screeds ................................................................. Extending Screeds ................................................................................................. Components of the Extending Screed ............................................................................ Compacting Systems Installed in Extending Screeds . ................................................ Extending Screeds and Bolt-on Extensions ................................................................... Set-Up of the Extending Screed . ...................................................................................... Mechanical Design and Maintenance of the Telescoping System ........................... Fixed-Width Screeds .............................................................................................. Components of the Fixed-Width Screed . ....................................................................... Compacting Systems Installed in Fixed-Width Screeds .............................................. Fixed-Width Screeds and Bolt-on Extensions . .............................................................. Set-Up of the Fixed-Width Screed .................................................................................... Screeds for the VISION Series of Pavers . ............................................................. VF Extending Screed (with Front-Mounted Extensions) . ........................................... VR Extending Screed (with Rear-Mounted Extensions) .............................................. Main Applications . ...............................................................................................................
30 32 32 34 36 38 48 50 50 52 54 60 62 62 64 66
3.1 General . ................................................................................................................ 3.2 Paving Material .................................................................................................... 3.3 Paving Parameters ............................................................................................... 3.4 Paver Set-Up ......................................................................................................... 3.5 Relationship Between Tamper Speed and Pave Speed ................................... 3.6 Recommended Settings for the Compacting Systems .................................... 3.7 Functions of the Hydraulic Rams for Raising / Lowering the Screed ............. 3.7.1 Screed Float ......................................................................................................................... 3.7.2 Screed Assist ........................................................................................................................ 3.7.3 Screed Freeze . .....................................................................................................................
86 88 89 89 92 93 94 95 95 95
4
Recommendations for Paving / Points to Note
97
4.1 4.1.1 4.1.2 4.1.3
Before Starting ..................................................................................................... Fundamentals . .................................................................................................................... Setting the Layer Thickness ............................................................................................. Weather Conditions when Paving Asphalt . .................................................................
1
2
Design of a Road Paver
7 8 10 12
Special Screed: AB 600 High Compaction Screed in TP2 Plus Version ........... Set-Up ................................................................................................................... Tamper .................................................................................................................................. Pressure Bar(s) ..................................................................................................................... Tamper Shield . .................................................................................................................... Side Plates ............................................................................................................ Mechanical-hydraulic Side Plate . ................................................................................... Hydraulic Side Plate from VÖGELE ................................................................................. Standard Side Plate from VÖGELE .................................................................................. Bevel Irons ............................................................................................................................ Screed Heating ..................................................................................................... Screed Maintenance ............................................................................................ Daily Maintenance ............................................................................................................. Weekly Maintenance .........................................................................................................
68 70 70 71 72 73 73 74 76 77 78 80 80 82
Parameters Influencing the Paving Process
85
98 98 100 104
3
contents
VÖGELE Booklet on Paving
5.3.3 Strips in the Lateral Areas of the Pavement ................................................................. 5.3.4 Patches of Mix in the Surface Texture . .......................................................................... 5.4 Imprints . ............................................................................................................... 5.5 Longitudinal Step ................................................................................................ 5.6 Non-Uniform Surface Structure due to Crushed Grains ..................................
168 169 170 170 171
6
173
4.1.4 4.1.5 4.1.6 4.1.7 4.1.8 4.1.9 4.1.10 4.2 4.2.1 4.2.2 4.2.3 4.2.4 4.2.5 4.2.6 4.2.7 4.2.8 4.3 4.3.1 4.3.2 4.3.3 4.3.4
Requirements Made on the Roadbase and its Surface ............................................. Augers and Limiting Plates for the Auger Tunnel on an Extending Screed ......... Definition and Preparation of the Route ...................................................................... The Optimal Sensor for Every Paving Application . .................................................... Ordering Asphalt from the Mixing Plant on Call . ....................................................... Preparing the Reference for Grade and Slope Control .............................................. Correct Positioning of the Grade and Slope Sensors ................................................. During the Paving Process .................................................................................. Positioning the Paver . ....................................................................................................... Head of Mix in Front of the Screed . ............................................................................... Joints in Asphalt Pavements ............................................................................................ Expansion Joints ................................................................................................................. Paving “Hot to Cold” .......................................................................................................... Paving “Hot to Hot” ............................................................................................................ Duties of the Paving Team during the Paving Process .............................................. Tools for Continuous Verification of the Paved Result . ............................................. After Paving .......................................................................................................... Subsequent Compaction by Rolling .............................................................................. Rules for Rolling and Avoiding Errors ............................................................................ Measurement of Density and Surface Accuracy ......................................................... Cleaning, Daily Maintenance and Completion of the Job Site . ..............................
105 108 110 111 122 123 124 125 125 126 127 131 132 133 134 136 138 138 142 143 144
6.1 General Pavement Structure .............................................................................. 6.2 Producing Asphalt Mix ........................................................................................ 6.3 Types of Pavement Layers . ................................................................................. 6.4 Bitumen Grades Used .......................................................................................... 6.5 Asphalt Types and their Composition ............................................................... 6.5.1 Stone Mastic Asphalt ......................................................................................................... 6.5.2 Asphaltic Concrete (Paved Hot) ...................................................................................... 6.5.3 Asphaltic Binder . ................................................................................................................ 6.5.4 Asphalt for Base Course .................................................................................................... 6.5.5 Porous Asphalt .................................................................................................................... 6.6 Mix Temperatures in °C . ...................................................................................... 6.7 Causes of Poor Quality Asphaltic Concrete Mixes for Hot Paving .................. 6.8 Emulsion Types . ...................................................................................................
174 180 184 185 186 186 188 190 192 194 196 197 198
5
Imperfect Paving
147
7
Special Equipment and Special Methods
201
5.1 5.2 5.2.1 5.2.2 5.2.3 5.2.4 5.2.5 5.3 5.3.1 5.3.2
Systematic Elimination of Paving Errors ........................................................... Paving Problems / Paving Errors ........................................................................ Irregularities when Passing over Mix . ........................................................................... Pavement Irregularities due to Large Screed Planing Angle ................................... Hump Formed when Resuming Paving ........................................................................ Short Irregularities in Transverse Direction . ................................................................ Periodic Irregularities in Longitudinal Direction . ....................................................... Segregation in General ....................................................................................... Transverse Strips ................................................................................................................. Strips in the Middle of the Pavement ............................................................................
148 158 158 159 160 161 162 164 166 167
7.1 7.2 7.3
Spray Technology . ............................................................................................... 202 Two-Layer Paving . ............................................................................................... 208 Material Feeders .................................................................................................. 216
8
Index / Notes
4
Paving Materials in Detail
221
5
VÖGELE Booklet on Paving
1
Design of a Road Paver
7
1.1 Differences between Construction Machinery and Pavers ................................. 8 1.2 Components of a Road Paver ............................................................................... 10 1.3 The Floating Screed Principle ............................................................................... 12 1.4 Theoretical Outline of the "Floating Screed Principle" without Grade and Slope Control ........................................................................ 13 1.5 Tracked Pavers and Wheeled Pavers . .................................................................. 14 1.6 VÖGELE Product Overview ................................................................................... 18 1.6.1 Paver Classification . ............................................................................................................. 20 1.7 Examples of Paver Applications ........................................................................... 22 1.7.1 Types of Paving ..................................................................................................................... 22 1.7.2 InLine Pave® / SprayJet Technology ................................................................................. 24 1.7.3 Paving Materials . .................................................................................................................. 26
6
7
1. Design of a Road Paver
VÖGELE Booklet on Paving
1.1
Differences between Construction Machinery and Pavers
As a general rule, paving materials can be spread and levelled with a bulldozer, grader or paver.
Bulldozer
Because of their superior physical properties, however, pavers have now replaced bulldozers and graders.
The working tool (blade) is firmly linked to the chassis via hydraulic rams. When passing over irregularities in the ground, these are transmitted to the blade to a greater extent, unless counteracted.
When a bulldozer passes over irregularities in the ground, these are extensively transmitted to the blade, as the leverage between blade and the irregularity is too short (see diagram) and short irregularities can consequently only be levelled out to a limited extent. On a paver, however, the screed is separate from the tractor unit: it floats! As a result, the screed has a very strong self-levelling effect when passing over minor irregularities. What‘s more, the kinematic conditions – height of the irregularity in relation to the lift of the screed’s leading edge via the long screed arm – ensure that such short irregularities are levelled out at a ratio of 1:5.
Lift of Blade
Grader
For this reason, a paver should be used for paving even in the lowest layers in order to obtain an increasingly level result with each successive layer.
The working tool (blade) is firmly linked to the chassis via hydraulic rams. When passing over irregularities in the ground, these are transmitted to the blade to a lesser extent, unless counteracted. Lift of Blade
Road Paver
Change in Screed Planing Angle
8
The working tool is not firmly linked to the chassis. The screed is carried by the mix (principle of the Floating Screed) and changes its position only as a result of changes in the screed planing angle. The screed moves up and down to a lesser extent than the actual irregularity.
9
1. Design of a Road Paver
VÖGELE Booklet on Paving
1.2
Components of a Road Paver
The Machines Made by VÖGELE
1. Material Hopper / Push-Rollers
5. Screed
Road pavers place all kinds of bituminous materials as well as materials for the roadbase. When the mix has been dumped into the paver’s material hopper by the feed lorry, conveyors transport the material in front of the screed. This is where the process of paving proper takes place. VÖGELE pavers stand out through their capability of producing high quality pavements, their excellent reliability as well as service-friendliness and ease of operation.
Feed lorries dump the paving material into the material hopper at the front of the road paver. The lorry wheels make contact with the push-rollers and run on these.
The screed is the core of the VÖGELE road paver. The screed acts upon the paving material by way of its own weight and the compactive effort of its compacting systems. This results in precompaction of the mix and profiling of the placed layer.
2. Conveyors Wide conveyors transfer the paving material from the material hopper through the conveyor tunnel inside the machine to the augers in front of the screed.
3. Traction In VÖGELE road pavers, powerful engines are installed for a high tractive effort. VÖGELE pavers come in tracked or wheeled versions.
8
6. Screed Heating In order to prevent the asphalt mix from sticking to the screed plates and the compacting elements (tamper, pressure bar(s)), electric heating is provided.
7. Adjustment of Screed Tow Points The tow point rams make it possible to vary the screed planing angle and hence the layer thickness via the screed arm.
8. Screed Assist / Screed Freeze 5 6 4
4. Augers 1
10
2
7
3
Depending on the working conditions on site, pressure is applied to the hydraulic rams linked to the screed arms, or the hydraulic rams are relieved of pressure. This influences the weight of the screed and consequently also its floating function (see page 94 onwards).
Augers fulfil the task of evenly spreading the mix in front of the screed. Augers are adjustable in width to match the width of the screed so that uniform compaction of the paving material is ensured at all times.
11
1. Design of a Road Paver
VÖGELE Booklet on Paving
1.3
The Floating Screed Principle
1.4 Theoretical Outline of the "Floating Screed Principle" without Grade and Slope Control
The “floating“ working tool is the main difference distinguishing a road paver from other construction machinery. In other words, the layer thickness only changes as a result of changes in the screed‘s planing angle or changes in the height of the screed tow points. This way, irregularities in the ground are diminished when passed over, without having to intervene through a control system. Short irregularities in the base are levelled out through the self-levelling property of the Floating Screed.
h = H = a = b =
Height after compensation Height of irregularity Depth of screed plate Length of screed arm + depth of screed plate
When passing over long irregularities, the height of the screed tow points changes, thus leading to a change in the layer thickness.
h H
Depending on the screed planing angle, more or less mix is packed under the screed as the paver advances, and the layer thickness gradually changes over a longer distance.
Height of Screed Tow Point
Speed
12
Properties of Mix
The response of the screed to such changes depends on: Pave speed Change in height of the screed tow points Properties of the mix (compactability, load bearing capacity).
a
b
The following rule can be derived from the example of a paver passing over a short irregularity: Taking into account different lengths (b) (extending over length of screed arm and depth of screed plate) for the different paver types, an average ratio of about 5 : 1 results as far as compensation of a short irregularity in the base is concerned.
Hxa h = b
Long irregularities in the base can only be levelled out by actively controlling the height of the screed tow points.
Note The evenness of the pavement must increase with every layer placed. The magnitude of improvement depends on the quality of the layer below.
13
1. Design of a Road Paver
VÖGELE Booklet on Paving
1.5
Tracked Pavers and Wheeled Pavers
VÖGELE pavers are available in tracked or wheeled versions. Each version offers its particular advantages.
Tracked Paver Crawler tracks transmit the power delivered by the high-performance engine to the ground. In contrast to wheels, crawler tracks have a larger contact area with the base, allowing them to achieve a higher tractive effort. For the tracked pavers, the power is generated where it is needed: right at the sprocket. The powerful undercarriage is ideal for use of the paver also on difficult terrain and in large pave widths up to 16m. For the two crawler tracks, separate electronic control is provided. This allows impeccable turning also of radii at a constant pave speed.
14
Advantages of the Tracked Paver High tractive effort. Universal application. Handles large pave widths. Easily pushes heavy feed lorries. Use also on a soft base.
15
1. Design of a Road Paver
VÖGELE Booklet on Paving
1.5
Tracked Pavers and Wheeled Pavers
Wheeled Paver Wheeled pavers display their strong points above all when it comes to frequent travels from one project to another. VÖGELE pavers travel at speeds up to 20km/h under their own power, so trucking is not required for job sites in the near surroundings. The wheeled VÖGELE pavers feature excellent manoeuvrability thanks to a turning radius of just 6.5m. For placing high-quality surface course, smooth running of the paver is a must. The wheeled VÖGELE pavers optimally achieve this goal thanks to the oscillating axle and the damping effect of their rear wheels.
16
Advantages of the Wheeled Paver Travel from one job to another under its own power. Travel speed up to 20km/h also on public roads. Ideal when frequent and quick transfer is required. Smooth running when paving asphalt wearing course. Excellent manœuvrability. Front wheels are in permanent contact with the ground thanks to oscillating axle.
17
1. Design of a Road Paver
VÖGELE Booklet on Paving
1.6
VÖGELE Product Overview
SUPER Series Machine Class
Type Weight
Mini Class
Tracked Paver SUPER 700
Compact Class
Universal Class
Highway Class
18
SUPER Series Basic Width
Maximum Pave Width
Maximum Laydown Rate
Machine Class
Type Weight
5.9t
1.1m
3.2m
200 tonnes/h
Special Class
SUPER 1800-2
with SprayJet Module
Tracked Paver SUPER 800
6.1t
1.1m
3.2m
250 tonnes/h
SUPER 1800-2 Slope Paver
Tracked Paver SUPER 1100-2
8.5t
1.8m
4.2m
300 tonnes/h
Wheeled Paver SUPER 1103-2
8.6t
1.8m
4.2m
200 tonnes/h
Tracked Paver SUPER 1300-2
9.5t
1.8m
5m
350 tonnes/h
Wheeled Paver SUPER 1303-2
9.5t
1.8m
4.5m
250 tonnes/h
Tracked Paver SUPER 1600-2
18.4t
2.55m
8m
600 tonnes/h
Wheeled Paver SUPER 1603-2
17t
2.55m
7m
600 tonnes/h
Tracked Paver SUPER 1800-2
19.3t
2.55m
10m
700 tonnes/h
Wheeled Paver SUPER 1803-2
17.3t
2.55m
8m
700 tonnes/h
Tracked Paver SUPER 1900-3
20.9t
2.55m
11m
900 tonnes/h
Tracked Paver SUPER 2100-3
21.9t
2.55m
13m
1,100 tonnes/h
Tracked Paver SUPER 3000-2
28.7t
3m
16m
1,600 tonnes/h
SUPER 2100-2 IP
for Paving Binder Course
Basic Width
Maximum Pave Width
Maximum Laydown Rate
20.8t
2.55m
6m
700 tonnes/h
23.6t
2.55m
5m
700 tonnes/h
26.6t
3m
8.5m
1,100 tonnes/h
Basic Width
Maximum Pave Width
Maximum Laydown Rate
VISION Series Machine Class
Type Weight
Universal Class
Tracked Paver VISION 5100-2
15.5t
2.45m
5.8m
700 tonnes/h
Wheeled Paver VISION 5103-2
14.9t
2.6m
5.8m
700 tonnes/h
Tracked Paver VISION 5200-2
19.4t
3m
8.6m
1,200 tonnes/h
Wheeled Paver VISION 5203-2
18.5t
3m
7.8m
1,200 tonnes/h
Basic Width
Maximum Pave Width
Maximum Conveying Capacity
Highway Class
PowerFeeder Series Machine Class
Type Weight
Special Class
PowerFeeder MT 3000-2
17t
3m
–
1,200 tonnes/h
PowerFeeder MT 3000-2 Offset
23t
3m
–
1,200 tonnes/h
19
1. Design of a Road Paver
VÖGELE Booklet on Paving
VÖGELE Product Overview
1.6.1
Paver Classification
Maximum Laydown Rate (tonnes/h)
1.6
1,600
Super 3000-2
1,500 1,400 VISION 5200-2
1,300
VISION 5203-2
1,200 1,100
Super 2100-3 SUPER 2100-2 IP for Paving Binder Course
SUPER 1800-2 with SprayJet Module
1,000
Super 1900-3
900
VISION 5103-2
800
VISION 5100-2
700
Super 1803-2 Super 1800-2
SUPER 1800-2 Slope Paver
SUPER Series
600 Super 1603-2
500 Super 1100-2
400 300
SUPER Series Super Series
Super 1300-2
Special Class
Super 1303-2
Super 800
200
Super 1600-2
Super 700
VISION Series VISION Series
Super 1103-2
16
15
14
13
12
11
10
9
7
6
5
4
3
2
1
100
Maximum Pave Width (m)
20
21
1. Design of a Road Paver
VÖGELE Booklet on Paving
1.7
Examples of Paver Applications
1.7.1
Types of Paving
Classical Application Placing all kinds of pavement layers for roadways and paths. Pavers are available in various performance classes and combine with a variety of screed options to handle these paving jobs. Layer thickness ranges from 2cm to 40cm.
Paving on a Slope (Vertical) Apart from construction of conventional roads with gradients (uphill or downhill), road pavers can also be used for special applications, such as paving on a slope for construction of dams, retaining walls, etc. In general, only slight conversion of the paver is required for handling jobs of this kind. For application under extreme conditions (steep slope), a special Slope Paver can be used that has undergone modification.
Paving on a Slope (Horizontal) As an alternative to paving in a vertical direction, pavers also work in a horizontal direction. In general, such applications, too, require no more than slight conversion of the paver. Paving work like this is also often found in the field of dam or canal construction.
22
Paving Asphalt Tracks or Special Profiles Extending screeds can be set up for paving a large variety of special profiles thanks to their systems for adjustment. Even positive or negative gull wing profiles (M or W profiles) can be handled when height adjustment of the extending units is combined with crown adjustment of the basic screed. Special slipforms are available for the construction of farm tracks or railway tracks.
Asphalt can also be paved on steep banks with the aid of special slipforms, for instance on racing circuits.
23
1. Design of a Road Paver
VÖGELE Booklet on Paving
1.7
Examples of Paver Applications
1.7.2
InLine Pave® / SprayJet Technology
SUPER 1800-2 with SprayJet Module
InLine Pave® Train
Paving a thin overlay on a spray seal or tack coat, hot on hot, is a cost-effective method of resurfacing existing roads, but it requires special machine technology.
The two-layer construction of asphalt pavements by “hot on hot“ paving constitutes a particularly efficient method of building long-lasting roads. With this method, the binder course and wearing course are placed “hot on hot“ in a single pass, thus yielding not only a perfect bond between layers but also strong interlocking. Both such two-layer pavements and conventional paving work can be realized most economically and in high quality when using InLine Pave® machine technology from VÖGELE.
With the SUPER 1800-2 with SprayJet Module, the existing road surface can be spread with bituminous emulsion and a new wearing course paved in a single operation. Site vehicles no longer drive over the emulsion, as it is directly overlaid with asphalt. In other words, a perfect tack coat is produced to ensure perfect bonding between the layers. What‘s more, the roads round about are no longer fouled when using this method, as vehicles do not drive over the emulsion.
The InLine Pave® train comprises three machines: a MT 3000-2 Offset material feeder, a SUPER 2100-2 IP paver for the binder course and a SUPER 1600-2 or SUPER 1800-2 for the wearing course. These machines run directly one behind the other, in a single line.
SprayJet technology is also ideal for placing low-noise wearing courses. In order to preserve the noise-absorbing cavities, the mix cannot be compacted to the same degree as conventional asphalt. The pavement quality would suffer when using the conventional two-step method, as thicker layers would be needed, but this would impair the pavement‘s durability due to the lesser compaction.
24
The paving process starts with the material feeder. It receives the binder and wearing course mixes supplied by feed vehicles and alternately transfers the mix either directly into the large material hopper of the paver for binder course or to the transfer module for the hopper of the paver for wearing course. The SUPER 2100-2 IP is responsible for paving a high-density binder course with high resistance to deformation. This paver is equipped with the special AB 600 High Compaction Screed in TP2 Plus version from VÖGELE. The third machine in the InLine Pave® train is a SUPER 1600-2 or SUPER 1800-2 for paving the wearing course.
25
1. Design of a Road Paver
VÖGELE Booklet on Paving
1.7
Examples of Paver Applications
1.7.3
Paving Materials
Paving Bituminous Material Throughout the world, pavers are the "No. 1" machine for placing wearing courses, binder courses and bituminous base courses of asphaltic concrete or stone mastic asphalt. Their advantages include the following features in particular: very good self-levelling properties, high and homogeneous precompaction, as well as the ability to heat all machine parts in contact with the material.
Paving PCC and RCC
Placing Roadbase Material or Water-bound Base Course Material
Pavers can even place materials such as PCC (Paver Compacted Concrete) and RCC (Roller Compacted Concrete) if the specifications for the PCC and RCC formulation are adhered to precisely.
Their self-levelling effect and physical advantages as compared to graders and bulldozers make pavers eminently suitable for building a crushed-stone roadbase or placing a water-bound base course.
PCC and RCC are frequently used, especially in North America and Asia, but they are also becoming more widespread in Europe, too, for instance for industrial areas.
26
Pavers are ideal, particularly when building long stretches of new road and for roads on which higher surface accuracy is required. Extensive and uniform basic stability is assured, especially in the lower layers, by their homogeneous compaction over the full width of the road.
27
VÖGELE Booklet on Paving
28
2
Screed
29
2.1 2.2 2.2.1 2.2.2 2.2.3 2.2.4 2.2.5 2.3 2.3.1 2.3.2 2.3.3 2.3.4 2.4 2.4.1 2.4.2 2.4.3 2.5 2.6 2.6.1 2.6.2 2.6.3 2.7 2.7.1 2.7.1.1 2.7.1.2 2.7.2 2.8 2.9 2.9.1 2.9.2
General Differences between Screeds ................................................................. Extending Screeds ................................................................................................. Components of the Extending Screed ............................................................................ Compacting Systems Installed in Extending Screeds . ................................................ Extending Screeds and Bolt-on Extensions ................................................................... Set-Up of the Extending Screed . ...................................................................................... Mechanical Design and Maintenance of the Telescoping System ........................... Fixed-Width Screeds .............................................................................................. Components of the Fixed-Width Screed . ....................................................................... Compacting Systems Installed in Fixed-Width Screeds .............................................. Fixed-Width Screeds and Bolt-on Extensions . .............................................................. Set-Up of the Fixed-Width Screed .................................................................................... Screeds for the VISION Series of Pavers . ............................................................. VF Extending Screed (with Front-Mounted Extensions) . ........................................... VR Extending Screed (with Rear-Mounted Extensions) .............................................. Main Applications . ............................................................................................................... Special Screed: AB 600 High Compaction Screed in TP2 Plus Version ............. Set-Up ..................................................................................................................... Tamper .................................................................................................................................... Pressure Bar(s) ....................................................................................................................... Tamper Shield . ...................................................................................................................... Side Plates .............................................................................................................. Mechanical-hydraulic Side Plate . ..................................................................................... Hydraulic Side Plate from VÖGELE ................................................................................... Standard Side Plate from VÖGELE .................................................................................... Bevel Irons .............................................................................................................................. Screed Heating ....................................................................................................... Screed Maintenance .............................................................................................. Daily Maintenance ............................................................................................................... Weekly Maintenance ...........................................................................................................
30 32 32 34 36 38 48 50 50 52 54 60 62 62 64 66 68 70 70 71 72 73 73 74 76 77 78 80 80 82
29
2. Screed
VÖGELE Booklet on Paving
2.1
General Differences between Screeds
The screed is the true heart of the VÖGELE paving system. It accommodates the compacting systems which provide high density and durable results. VÖGELE screeds are available in two versions: as Fixed-Width Screeds (SB) or Extending Screeds (AB).
Extending Screed
The screed, the road paver‘s working tool, fulfils the function of uniformly compacting the paving material across the entire pave width and producing a close-textured and level surface. The screed‘s compacting systems must precompact the mix to the greatest possible extent. This minimizes the influence of layer thickness on the amount of subsequent compaction by rolling when bringing about the pavement’s final density. For precompaction, different compacting systems are available. The abbreviations for the compacting systems are as follows: T = Tamper (an eccentric shaft causes the tamper bar to move up and down). V = Vibrators (vibrations are generated by an eccentric shaft acting on the screed plates at right angles to the direction of motion). P = Pressure Bar(s) (the pressure bar(s) are hydraulically pressed onto the mix at a frequency of 68 Hz (approx.) and a maximum pressure of 130 bar). P1 = Screed equipped with 1 Pressure Bar
Variable screed, customarily used today. Limited pave widths. Vast range of uses.
Ideal for all manner of jobs requiring variability and adaptability.
Fixed-Width Screed
P2 = Screed equipped with 2 Pressure Bars
Large pave widths. Hydraulic extending units enlarge the range of uses.
30
Highly accurate paving true to line and level. Suitable for high compaction, e.g. when placing water-bound base, RCC and PCC.
31
2. Screed
VÖGELE Booklet on Paving
2.2
Extending Screeds
2.2.1
Components of the Extending Screed
Single-Tube Telescoping System
Hydraulic Ram for Screed Width Control
Screed’s Hydraulically Extending Unit
Torque Restraint System
Screed Body
Tamper with Heating Rod Eccentric Vibrators
32
Screed Plate with Heating Element Monitoring Unit for Heating Rods
33
2. Screed
VÖGELE Booklet on Paving
2.2
Extending Screeds
2.2.2
Compacting Systems Installed in Extending Screeds
V = Vibrators
TP1 = Tamper and 1 Pressure Bar
Installed in: AB 200 Extending Screed AB 340 Extending Screed Recommended for: Materials which are easy to compact.
Installed in: AB 500 Extending Screed AB 600 Extending Screed Recommended for: All conventional mixes. Precompaction by a screed in TP1 version is higher than by a TV screed, but lower than by a screed in TP2 version. Less extra compaction by rolling required.
TV = Tamper and Vibrators
TP2 / TP2 Plus = Tamper and 2 Pressure Bars
Installed in: AB 200 Extending Screed AB 340 Extending Screed AB 500 Extending Screed AB 600 Extending Screed Recommended for: All conventional mixes. Use with wheeled pavers due to the lower weight as compared to screeds in TP1 or TP2 versions. Materials which are easy to compact.
34
Installed in: AB 500 Extending Screed (TP2) AB 600 Extending Screed (TP2/TP2 Plus) Recommended for: All conventional mixes. The screed in TP2 version achieves high precompaction when placing thick layers. The screed in TP2 Plus version is used above all for base and binder courses due to its high compacting effort. Mixes which are difficult to compact on account of their grain shapes and consistency. Less extra compaction by rolling required. Jobs which do not allow subsequent compaction by rolling.
35
2. Screed
VÖGELE Booklet on Paving
2.2
Extending Screeds
2.2.3
Extending Screeds and Bolt-on Extensions
For all VÖGELE screeds, bolt-on extensions are available. The VÖGELE system of bolt-on extensions makes it possible to easily and sturdily build up screeds to any pave width desired. Even when paving in large widths, VÖGELE screeds work with highest precision and achieve superb degrees of uniform density right up to the pavement edges.
AB 200
AB 340 0.8m
When fitting bolt-on extensions, care must be taken to ensure that the bottom edge of the screed plate is flush with the adjacent units, otherwise a step may be produced in the pavement or the screed planing angle may change. During the paving process, this can have a negative effect on precompaction, surface structure and floating behaviour of the screed.
0.45m 1.1m 0.45m 2m
1.8m 3.4m
0.8m
2 x 0.25m 3.9m 2 x 0.4m
2 x 0.35m
4.2m
2.7m
2 x 0.55m 4.5m 2 x 0.80m
2 x 0.6m 3.2m
5m
AB 500
AB 600 1.225m
36
2.55m 5m
1.225m
1.5m
3m 6m
2 x 0.25m
2 x 0.25m
5.5m
6.5m
2 x 0.75m
2 x 0.75m
6.5m
7.5m
2 x 0.75m + 2 x 0.25m
2 x 0.75m + 2 x 0.25m
7m
8m
2 x 1.25m
2 x 1.25m
7.5m
8.5m
4 x 0.75m
4 x 0.75m
8m
9m
4 x 0.75m + 2 x 0.25m
4 x 0.75m + 2 x 0.25m
8.5m
9.5m
1.5m
37
2. Screed
VÖGELE Booklet on Paving
2.2
Extending Screeds
2.2.4
Set-Up of the Extending Screed
Setting Up the Screed: Prerequisites 1. Clearance between sliding blocks and sliding rail has been set and checked (see page 48).
5
2. Height adjustment: Adjusting spindles have been set and checked (see pages 42 onwards). 3. Screed has been raised and laid down on locking bolts. 4. Both tow point rams are in their lowest position. 5. Crown has been set to 0%. 6. Clamping screw for height adjustment is released. 7. Height adjustment of the extending screed has been set to 0 on the scale.
3
4
5
6
38
7
39
2. Screed
VÖGELE Booklet on Paving
2.2
Extending Screeds
2.2.4
Set-Up of the Extending Screed
Setting the Screed Planing Angle: Outer Extending Screed Retract the screed completely. Hold the ruler [4] under the screed plates in the area of the outer adjusting spindles. Set the extending unit via the mechanism for height adjustment so that the ruler makes contact with the three points [1], [2] and [3]. Measure the clearance. About 30mm behind the rear edge of the tamper, there must be a gap of roughly 1mm between the ruler and the screed plate. Unscrew the chains on the adjusting spindles. Make the setting at the front adjusting spindle with a suitable tool. Measure the clearance and repeat the procedure if necessary.
Setting the Screed Planing Angle: Inner Extending Screed Extend the screed until the adjusting spindles are located under the sliding blocks. Hold the ruler [4] under the screed plates in the area of the inner adjusting spindles. Set the extending unit via the mechanism for height adjustment so that the ruler makes contact with the three points [1], [2] and [3].
4
Measure the clearance. About 30mm behind the rear edge of the tamper, there must be a gap of roughly 1mm between the ruler and the screed plate. Unscrew the chains on the adjusting spindles.
1
Make the setting at the front adjusting spindle with a suitable tool.
2
3
Measure the clearance and repeat the procedure if necessary.
note Retighten the clamping screw for height adjustment after setting the screed planing angle. Then check the setting again.
40
41
2. Screed
VÖGELE Booklet on Paving
2.2
Extending Screeds
2.2.4
Set-Up of the Extending Screed
Height Adjustment, Adjusting Spindle Setting the Adjusting Spindle Without unscrewing the locking bolts, check the slack of the threaded bush [1]. Procedure: Lower the screed with extending units onto wooden blocks. Open the chains [2] by means of the shackle type connector. Turn the adjusting spindles [3] down to ensure that their face end [5] rests completely on the flange surface of the screed frame. Remove the hexagon socket screw [1] from the flange. Tighten the threaded bush [4] with a suitable tool.
3
Back off the threaded bush [4] with a 45° turn until the hole of the locking screw is free. Tighten down the hexagon socket screw [1].
4
2 1
note
5
Always set all four spindles for each extending screed.
42
43
2. Screed
VÖGELE Booklet on Paving
2.2
Extending Screeds
2.2.4
Set-Up of the Extending Screed
Preparation Support the screed on large wooden blocks or pallets to compensate for any unevenness of the ground. Flange surfaces must be clean, i.e. free from asphalt.
TIP!
Height Adjustment of the Bolt-on Extension The height of the extending unit and bolt-on extension in relation to one another is adjusted via the eccentric bolts so that the trailing edges of the screed plates are flush while the leading edges are between 0.5 and 1mm higher.
Before mounting a bolt-on extension, the tamper shafts of both the screed’s extending unit and the bolt-on extension must be set so that the arrow on the coupling points to the gap in the gearwheel (see photo).
Easy and Fast Attachment with Quick-fitting Aid The bevelled quick-fitting aid makes it possible to raise a bolt-on extension without tightening down the screws. This allows an extension to be fitted even on an uneven base.
TIP! The front and rear eccentric bolts must be set to zero position (uppermost position). This is important later on for aligning the extending unit with the basic screed.
44
1mm (maximum)
0mm
Fitting the Braces The frames of the screed‘s extending unit and of the bolt-on extension must be joined. T hen fit the braces stabilizing the bolt-on extensions. These braces must be adjusted so that a light downwards pressure is exerted onto the extension.
TIP! The pressure is correct if the brace can be turned slightly. If it cannot, the pressure is too high.
45
2. Screed
VÖGELE Booklet on Paving
2.2
Extending Screeds
2.2.4
Set-Up of the Extending Screed
Connecting Systems Now connect the heating (upper photo). Then connect the tamper shaft to the Haldex coupling (middle photo).
The following steps only need to be carried out when fitting bolt-on extensions to VÖGELE High Compaction Screeds with 1 or 2 pressure bars (TP1 or TP2).
Joining the Pressure Bars When mounting bolt-on extensions to VÖGELE High Compaction Screeds, two extra steps need to be carried out (see right).
Final Assembly Finally, the tamper shield, the auger shafts and the footboard with cover plate are to be fitted.
Joining of pressure bar 1 (and 2, if equipped) of the bolt-on extension with those of the basic screed using spring washers and a spacer block. The bottom edges of the pressure bars must also feel flush (see photo). Then check the pressure bars for smooth and free movement. Vent the pressure bar(s) at specified intervals.
Special tools for joining the pressure bars: The tools required are a standard ratchet, a hexagon adaptor and an Allan key.
Connecting Hydraulic Piping Connect the hydraulic piping, e.g. to the pressure bar. All further steps are identical for all screed types.
46
47
2. Screed
VÖGELE Booklet on Paving
2.2
Extending Screeds
2.2.5
Mechanical Design and Maintenance of the Telescoping System
Telescoping Tubes
The telescoping tubes must be regularly lubricated with silicone grease. Contact with sharp-edged objects (blades, etc.) must be avoided. Ensure a perfect seal between the individual tubes. If possible, the underside of the tubes should not be allowed to come into contact with asphalt (e.g. when rapidly extending and retracting the screed).
Internal Guide Tubes The guide tubes must be regularly lubricated with silicone grease.
Contact with sharp-edged objects (blades, etc.) must be avoided. Ensure a perfect seal between the individual tubes. If possible, the underside of the tubes should not be allowed to come into contact with asphalt (e.g. when rapidly extending and retracting the screed).
Others Torque Restraint System The sliding blocks and the rail of the torque restraint system must be greased regularly. The sliding blocks must be set so that they make contact without play during operation. Worn sliding blocks must be replaced.
48
Particularly the leading edge of the screed and the tamper area must be washed down with cleaning agent every morning and evening. Let the tamper run at low speed so that the cold material can drip onto a suitable substrate. Ensure that the pressure bars in particular can move freely.
49
2. Screed
VÖGELE Booklet on Paving
2.3
Fixed-Width Screeds
2.3.1
Components of the Fixed-Width Screed
Tamper with Heating Rod
Pressure Bars with Heating Rods
Basic Screed
Bolt-on Extension
Screed Plate with Heating Element
Eccentric Vibrators
50
51
2. Screed
VÖGELE Booklet on Paving
2.3
Fixed-Width Screeds
2.3.2
Compacting Systems Installed in Fixed-Width Screeds
TV = Tamper and Vibrators Installed in: SB 250 Fixed-Width Screed SB 300 Fixed-Width Screed Recommended for: All conventional mixes. Materials which are easy to compact or thinner pavement layers. Jobs where paving can be done in a largely constant width and where large radii are involved.
Installed in: SB 250 Fixed-Width Screed (and Hydraulic Bolt-on Extensions) SB 300 Fixed-Width Screed (and Hydraulic Bolt-on Extensions) Recommended for: All conventional mixes. A screed in TP2 version achieves a high precompaction even of thick pavement layers. Mixes which are difficult to compact on account of their grain shape and consistency. Jobs where paving can be done in a largely constant width and where large radii are involved. Less effort required for subsequent compaction by rolling.
TP1 = Tamper and 1 Pressure Bar
TVP2 = Tamper, Vibrators and 2 Pressure Bars
Installed in: SB 250 Fixed-Width Screed (and Hydraulic Bolt-on Extensions) SB 300 Fixed-Width Screed (and Hydraulic Bolt-on Extensions) Recommended for: All conventional mixes. Precompaction by a screed in TP1 version is higher than by a TV screed, but lower than by a screed in TP2 version. Jobs where paving can be done in a largely constant width and where large radii are involved. Less effort required for subsequent compaction by rolling.
52
TP2 = Tamper and 2 Pressure Bars
Installed in: SB 250 Fixed-Width Screed SB 300 Fixed-Width Screed SB 250 B Fixed-Width Screed Recommended for: Jobs where paving can be done in a largely constant width and where large radii are involved. SB 250, SB 300: All conventional mixes. SB 250 B: For paving PCC®, as this type of job does not include subsequent compaction by rolling.
53
2. Screed
VÖGELE Booklet on Paving
2.3
Fixed-Width Screeds
2.3.3
Fixed-Width Screeds and Bolt-on Extensions
As a general rule, bolt-on extensions should be fitted symmetrically on both sides of the screed wherever possible. The advantage of a Fixed-Width Screed is a deeper screed plate of 500mm compared to a screed plate of 250mm found on Extending Screeds. This has a positive effect upon the screed‘s floating behaviour. Moreover, the leading edge of the Fixed-Width Screed forms a single line over the entire pave width and different planing angles do not leave marks in the pavement. Fixed-Width Screeds are capable of handling considerably larger pave widths than Extending Screeds, albeit with restrictions as regards the screed‘s variability. As a result, Fixed-Width Screeds are particularly suited to paving long sections with a large, unchanging pave width.
Hydraulic bolt-on extensions allow infinite variation of pave width also for Fixed-Width Screeds.
note The hydraulic bolt-on extensions (0.75m) can only be fitted to mechanical extensions with a width of 1m or more. The basic screed must be built up by at least 1.5m on both sides in order to mount the hydraulic bolt-on extensions.
54
55
2. Screed
VÖGELE Booklet on Paving
2.3
Fixed-Width Screeds
2.3.3
Fixed-Width Screeds and Bolt-on Extensions
Top View Building up a SB 300 Fixed-Width Screed to its maximum pave width
Basic Screed 3m 1.5m
Horizontal Bracing
1.5m
1.5m
0.25m
1.5m
1.5m
6m 6.5m
0.5m
1.5m
1.5m
1.5m
1.5m
0.25m
12m 12.5m 0.5m 0.25m
1.5m
0.5m
0.5m
7m 7.5m 1.5m 1m
1.5m
1.5m
1m
1.5m
1.5m
1m
1.5m
1.5m
1.5m 0.25m
0.25m 13m 13.5m
8m 8.5m 0.5m
1.5m
1.5m
1.5m
0.25m 1m
1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
1m
9m 9m 0.5m 0.25m
14m 14.5m 1m
1.5m
1.5m
0.5m
1.5m
0.5m 9.5m 10m 0.5m 0.25m
1.5m
1.5m
1m 1.5m
1.5m
1m
1.5m
1.5m
56
1.5m
1.5m
15m 15m
0.25m 1.5m
11.5m 12m
1.5m
1m
10.5m 11m 0.25m
1.5m
1.5m
1m
0.5m
1.5m
0.5m 1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
15.5m 16m
57
2. Screed
VÖGELE Booklet on Paving
2.3
Fixed-Width Screeds
2.3.3
Fixed-Width Screeds and Bolt-on Extensions
Rear View Building up a SB 300 Fixed-Width Screed to its maximum pave width
Basic Screed 3m
Basic Screed 3m
Vertical Bracing
0.25m
0.25m 1m
1.5m
1.5m
1.5m
1.5m
6m 6.5m
1.5m
1.5m
1.5m
1.5m
11.5m 12m
0.5m 0.25m
0.5m 1.5m
0.75m
1.5m
1.5m
1.5m
1.5m
7m 7.5m
1m
1.5m
1.5m
1m
12m 12.5m
0.25m 1m
1.5m
0.5m 0.25m
0.5m 1.5m
1.5m
1.5m
8m 8.5 m
1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
13m 13.5m
0.5m 0.75m 1m
1.5m
1.5m
1m
1.5m
1.5m
1.5m
1.5m
9m 9m
1m
1m
14m 14.5m 1m
0.25m
0.5m 1.5m
1.5m
1.5m
1.5m
0.5m
1.5m
1.5m
1.5m
9.5m 10m
1.5m
15m 15m 0.25m
0.5m 0.25m 1.5m
1.5m
1.5m 10.5m 11m
58
1.5m
1.5m
1m
1.5m
0.5m
1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
1.5m
15.5m 16m
59
2. Screed
VÖGELE Booklet on Paving
2.3
Fixed-Width Screeds
2.3.4
Set-Up of the Fixed-Width Screed Bolt-on extensions are fitted to enlarge the screed’s width. The trailing edges of the screed plates must be flush across the entire pave width. The leading edges of the screed plates (each bolt-on extension) should be set higher towards the outside by roughly 0.5mm. +0.5mm
+0.5mm +0mm
+0mm
Top View
1.5m
Sag
1.5m
1.5m
Basic Screed
1.5m
1.5m
1.5m
To compensate the uplift at the outer edges of the screed, the screed should sag slightly when raised. The magnitude of this sag depends on the pave width. The sag can be adjusted by way of the braces over the screed’s basic unit.
In order to prevent the bolt-on extensions from bending towards the rear as a result of the pressure exerted by the mix, horizontal braces must be fitted.
Recommendation
Pave Width
Sag
16m
5.5cm (approx.)
12m
3.5cm (approx.)
up to 10.5m
2cm (approx.)
Rear View
Attention!
Horizontal braces should be fitted in such a way that the trailing edges of the screed plates are flush.
60
The values indicated in the table are approximate values for set-up of the screed. When paving, the transverse evenness of the pavement must be checked and the braces re-adjusted, if necessary.
61
2. Screed
VÖGELE Booklet on Paving
2.4
Screeds for the VISION Series of Pavers
2.4.1
VF Extending Screed (with Front-Mounted Extensions)
3.05m 5.95m
6.55m Robust and smooth guide system for precise operation at all widths.
Sloping extension up to 10%.
Basic width 3.05m.
Easy-to-use ErgoPlus® operating system.
Infinitely variable range 3.05m up to 5.95m. Maximum pave width 7.75m. Suitable for many screed profiles with crown and sloping extensions. Berm is available as an option.
62
7.15m
Innovative electric screed heating. Compact design allows for great visibility in all areas. Ideal tool for multivariable width applications and mainline paving.
7.75m
Pave Widths Basic Width Infinitely Variable Range
3.05m to 7.75m (dependent on type of tractor unit) 3.05m 3.05 up to 5.95m
Larger Width Bolt-on Extensions
30cm 60cm
Crown Adjustment Hydraulic
-2.5% to +5% M, W or parabolic profiles possible
Transverse Slope Extending Units
up to 10%
Berm Profiles
30cm, 45cm and 60cm available
Compacting System Screed Version V Vibrators (V) eccentric vibrators, frequency up to 50 Hz Screed Heating screed plates heated electrically by heating rods Dimensions (Transport, Basic Screed) Width 3.05m Depth 1.17m Weight 3.72t
63
2. Screed
VÖGELE Booklet on Paving
2.4
Screeds for the VISION Series of Pavers
2.4.2
VR Extending Screed (with Rear-Mounted Extensions)
3.05m 6m
2 x 0.65m 7.3m Large dimensioned, sturdy telescoping tubes featuring high-precision operation. They provide for excellent stability of the screed, ensuring great paving results. The telescoping tubes of the screed are located in a high position, thus avoiding any contact with the mix. Even with the screed set to its maximum width, the telescoping tubes are extended by no more than half, which provides for zero flexing. Deep screed plate design provides excellent floatation.
The attachment of the telescoping tubes, the support of the guide tubes and the torque restraint system make up a sturdy 3-point suspension, absorbing the forces exerted on the screed while paving and guaranteeing smooth width control of the extensions. Basic width 3.05m. Infinitely variable range 3.05m up to 6m. Maximum pave width 8.6m. Sloping extension up to 10%. Sturdy telescoping system with 3-point suspension. Innovative electric screed heating system. Easy-to-use ErgoPlus® operating system.
64
4 x 0.65m 8.6m
Pave Widths Basic Width Infinitely Variable Range
3.05m to 8.6m (dependent on type of tractor unit) 3.05m 3.05m up to 6m
Compacting System Screed Version V Vibrators (V) eccentric vibrators, frequency up to 50 Hz
Larger Widths Bolt-on Extensions
65cm
Screed Heating screed plates heated electrically by heating rods
Crown Adjustment Hydraulic
-2.5% to +5% M, W or parabolic profiles possible
Transverse Slope Extending Units
Dimensions (Transport, Basic Screed) Width 3.05m Depth 1.24m Weight 3.75t
up to 10%
65
2. Screed
VÖGELE Booklet on Paving
2.4
Screeds for the VISION Series of Pavers
2.4.3
Main Applications
Screed with Front-Mounted Extensions for Multivariable Width Applications
Screed with Rear-Mounted Extensions for Multi-Lane Paving
Working at high pave speeds with varying pave widths requires a screed that can always be relied on to deliver precise results. The VF 600 from VÖGELE is just such a system.
When paving across large widths, absolute accuracy of line and level is a crucial criterion for prime-quality results, regardless of the pave width and layer thickness involved. The VÖGELE VR 600 Extending Screed boasts impressive abilities in this respect: its basic width is 3.05m and it can be extended hydraulically up to 6m – nearly twice the basic width. With bolt-on extensions fitted, the screed builds up to a maximum width of 8.6m and is equipped with vibration across the full pave width. The quick-fitting system allows the 0.65m wide bolt-on extensions to be mounted very easily and quickly.
Several constructive features greatly support fast and precise retraction of the screed. For instance, the material offers virtually no resistance at the bevelled leading edges of the extensions, and blockades and obstacles are avoided. An additional advantage is that the side plates of a front-mounted screed are only about half as long as those of a rear-mounted screed, permitting particularly precise paving, working close up to obstacles. This, in turn, reduces the subsequent need for shovelling. Its variability is also evidenced in the wide range of possible profiles. All features combine to make the VF 600 equally suitable for building intersections on highways and for surfacing country roads with multiple obstructions. It is above all invaluable when tackling multivariable applications with many obstacles which require frequent changes in pave width, such as parking lots with several islands, light poles and storm sewers or residential and city streets with gas and water mains.
66
Based on its outstanding overall technical concept, the VR 600 is the perfect choice for medium and large-scale road construction projects. When it comes to paving asphalt layers across multiple lanes, the new screed also yields substantial advantages over single-lane paving as it avoids joints, the weak points in every asphalt pavement.
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2. Screed
VÖGELE Booklet on Paving
2.5
Special Screed: AB 600 High Compaction Screed in TP2 Plus Version
The pressure bars P1 and P2 are the last elements in the process of compaction as a whole. Logically, they are located in the rear area of VÖGELE HPC screeds. Only in this location can the highest possible compactive effort be achieved, as the mix is prevented from yielding to the front. Nor can it yield to the sides where it is confined by the screed‘s end plates. A change from high compaction to standard compaction and vice versa can easily be made from the paver operator’s console. This allows use of the screed for most varied applications.
Return Pipe
Pulse Generator
Tank
Pressure Bar
The element at the beginning of the process of VÖGELE High Compaction is the pulse generator as part of the pulsed flow hydraulics. It generates high-frequency pressure pulses. The pressure bar(s), in contrast to the beating tamper bar, remain in permanent contact with the mix, thus forcing the mix down for a prolonged period of time. Thanks to the high density achieved by the pressure bar(s), fewer passes are required for subsequent compaction by rolling.
In recent years, the AB 600 in TP2 Plus version has been developed further and perfected to meet the special requirements of "hot on hot" paving. On an InLine Pave® contract, it achieves an extraodinarily high degree of precompaction. Depending on the paving material used, the resultant compaction comes very close to the final density. The AB 600 Extending Screed in TP2 Plus Version at a Glance Uses: for "hot on hot" paving of binder and base courses, as well as thick roadbase packages. Maximum pave width 8.5m. Supplementary weight for additional compaction. Innovative tamper geometry: modified tamper shield so that material is drawn under the screed more effectively. Variable tamper speed up to 1,800 rpm. Special tamper stroke settings 4, 7 or 9mm. 2 pressure bars with infinitely variable pressure from 40 to 120 bar.
High precompaction is essential for perfectly building up a pavement in layers and for a pavement profile true to line and level. When paving layers varying in thickness, VÖGELE High Compaction Technology ensures that, although an identical pressure is applied across the screed width, the pressure bar(s) are forced down to varying depths. This way, an absolutely uniform density is produced. For each compacting system installed in a VÖGELE HPC screed, separate control is provided. Fine control of the pressure for pressure bar(s) allows use of VÖGELE High Compaction Technology for paving surface course, too.
Key:
68
T = Tamper
P1 = Pressure Bar 1
P2 = Pressure Bar 2
69
2. Screed
VÖGELE Booklet on Paving
2.6
Set-Up
2.6
Set-Up
2.6.1
Tamper
2.6.2
Pressure Bar(s)
Eccentric Shaft at Lower Reversal Point
1 2
Tamper 1mm at Stroke Length of 4mm
Bevelled Edge of Screed Plate
Screed Plate
The tamper must be set to an identical stroke length across the entire pave width. The setting can be changed by simply turning the eccentric bush on the shaft driving the tamper bar. The driving shaft is accessible from behind, so that this can easily be done between job site sections. Adjusting the lower reversal point of the tamper bar, however, takes more time. First, the tamper shields need demounting. Then remove the screws on all shaft brackets. After loosening the locking nut (2), the tamper bar can be adjusted via bolt (1). The height to be set depends on the tamper stroke selected.
1 4 8
7
0mm
Bevelled Edge of Screed Plate Screed Plate
Tamper Stroke 4mm
1mm
Bevelled Edge of Screed Plate Screed Plate
Tamper Stroke 7mm
2.5mm
Bevelled Edge of Screed Plate Screed Plate
Tamper Stroke 2mm
Tamper Stroke 4mm
Tamper Stroke 7mm
The tamper bar at the lower reversal point is flush with the bevelled edge of the screed plate.
The tamper bar at the lower reversal point is 1mm lower (maximum) than the bevelled edge of the screed plate.
The tamper bar at the lower reversal point is 2.5mm lower than the bevelled edge of the screed plate.
2 4
5 6
59.5mm
4mm Tamper Stroke 2mm
3
6
Pressure Bar
Screed Plate
0.5 - 1mm
0.5 - 1mm
1. Unscrew the nut (2) with anti-twist device (3) on the hydraulic ram (1) for the pressure bar. 2. Turn the hydraulic ram (1) to adjust the height of the pressure bar. The clearance (7) between pressure bar and bottom edge of the screed plate should be at least 4mm. 3. Check that the hydraulic ram for the pressure bar makes contact with metal plate (5) when retracted. 4. Set pre-tension of spring (6) to 5.5mm via nut (4) to yield a distance (8) of 59.5mm. 5. Resecure the hydraulic ram (3) for the pressure bar.
Tip! At a stroke length of 2mm, the tamper bar should be flush with the screed plate (check with your hand).
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71
2. Screed
VÖGELE Booklet on Paving
2.6
Set-Up
2.7
Side Plates
2.6.3
Tamper Shield
2.7.1
Mechanical-hydraulic Side Plate
Adjusting the height of the screed’s side plates is a frequently used function during the paving process. As a user, you know from experience that this function is often needed when paving along high or low kerbs, for instance, or along gutters.
6
How side plates help ensure a perfect pavement quality They prevent the mix spreading sideways while paving. They produce perfect longitudinal joints or pavement edges. They provide for optimal compaction in the pavement’s lateral areas.
5
4 3 1
2 0mm 0.5 - 1mm
The tamper (3) must be set so that it rests on the wear strip (1) across the full width. Then adjust the spring steel bar (2) on the tamper shield by means of screw (4) from the rear of the screed until a gap of 0.5 - 1mm is obtained between tamper bar and the spring steel bar. Release screws (6) and fit various small shims (5) to align the tamper shield. With the tamper shield correctly aligned, the spring steel bar (2) is at least parallel with the tamper or preferably inclined slightly to the front. Check and if necessary correct the clearance between tamper and spring steel bar.
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VÖGELE Booklet on Paving
2.7
2. Screed
Side Plates
2.7.1.1 Hydraulic Side Plate from VÖGELE Side plates hydraulically adjustable in height are an option for the AB 500 and AB 600 Extending Screeds. They provide for even more operating comfort. In contrast to mechanical adjustment by spindle equipped as standard, the hydraulic side plate is adjusted conveniently at the flip of a switch. For height adjustment, two hydraulic rams are installed on each side plate.
The side plate of the screed is raised or lowered simply by operating the tumbler switch.
The advantages of a hydraulic side plate become evident if the hydraulic ram for height adjustment has been extended completely by mistake.
If any unevenness is encountered in the base (as shown here by the piece of timber), the pressure in the hydraulic ram increases.
A VÖGELE paver equipped with hydraulic side plates.
74
As soon as it reaches 15 bar, a valve opens retracting the hydraulic ram. This prevents the screed from getting blocked. The screed keeps floating.
75
2. Screed
VÖGELE Booklet on Paving
2.7
Side Plates
2.7
Side Plates
2.7.1.2 Standard Side Plate from VÖGELE
2.7.2
Bevel Irons
When using a side plate provided as standard on VÖGELE screeds, care must be taken that the chain holder is not set too low. The chain must have “sufficient play”. This is important as otherwise the screed cannot float.
Bevel irons shape and compact the edges of the pavement. They are available with a bevel edge of 45°, 52° and 60°. Their size depends on the thickness of the layer to be paved. A heating rod can be installed as an option to improve the sliding properties of the bevel iron.
Please remember: Floating of the screed means that the thickness of the layer to be paved is determined merely by the screed planing angle and the height of the screed’s tow point. This way, irregularities in the pavement are avoided without active control.
Layer Thickness
Angle
45° (old)
52° (current)
60° (old)
4 - 6cm
The chain holder should be roughly in the middle and the chain must have sufficient play. In this way, the screed can float without hindrance resulting in a perfect pavement.
6 - 12cm
12 - 18cm
TIP! Side plate skis and bevel irons from VÖGELE fit both the hydraulic side plates and the ones provided as standard.
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2. Screed
VÖGELE Booklet on Paving
2.8
Screed Heating
All screed components in contact with the hot mix should be heated to approx. 90 °C before starting work.
1
It is recommended to protect the screed against excessive loss of heat to the surroundings so that the heating power can be utilized effectively.
5
This is achieved by lowering the screed until it is about 5cm above the ground to minimize the cooling effect of the wind.
2 3
6 7 4
The floating behaviour of the screed may vary before it reaches its operating temperature, with the result that layer thickness may also vary and deviate from that required.
In the morning, it is ready for operation after about 30 minutes. Then lay the screed on the hot mix and pave the first 2 - 3m. Now wait roughly 5 minutes so that the screed is uniformly heated by the mix.
1 Engine 2 Control Desk 3 Control Box / Fuse Box 4 Distributor Box 5 Generator 6 Tamper with Heating Rod 7 Screed Plate with 2 Heating Rods
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Asphalt may stick to the tamper bar, screed plates or pressure bar(s) if the screed temperature is too low. This can lead to the formation of strips and an irregular surface texture.
For the “dash 2“ machines, a monitoring unit for screed heating is available as an optional extra. This feature monitors each single heating rod for proper function and indicates any fault without delay. If one of the green indicator lamps goes out for a longer period of time, this means that the heating rod is defective.
Tip!
Advantage
Directly after switching on the screed heating, correct operation of the heating rods can be checked by cautiously touching the tamper bar, screed plates and pressure bar(s).
Since failure of a heating rod is detected immediately, it can be replaced without delay.
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2. Screed
VÖGELE Booklet on Paving
2.9
Screed Maintenance
2.9.1
Daily Maintenance
The screed is the tool used by the screed operator. Like every other tool, the screed must always be serviced and checked before it is used. Among other things, this includes daily visual inspection for defects. The locking screws of the mechanism for height adjustment (1) must be tested to ensure they function correctly and are secured with lock nuts. The clearance of the torque restraint system (2) and extending screeds must be checked regularly! The hot screed must be washed down with cleaning agent before and after use. Tamper and vibrators, conveyors and augers should run at low speed during this time. The "dash 2" machines have a special cleaning mode for this purpose.
1
T he telescoping tubes and all internal guide tubes must be coated with silicone grease to prevent asphalt sticking to them. Always coat the sliding blocks and the mechanism for crown adjustment with copper paste.
2
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2. Screed
VÖGELE Booklet on Paving
2.9
Screed Maintenance
2.9.2
Weekly Maintenance
Greasing the bearings for tamper and vibrators Example: tamper on the AB 500 Extending Screed
Tamper lube point on the right-hand side of the basic screed.
Tamper lube point on the right-hand extending unit.
Example: tamper on the AB 200 Extending Screed
The screed bearings should be greased every 50 hours of operation. This is indicated by self-adhesive pictograms on all screeds. Only use high-temperature grease (resistant to temperatures of up to 200 °C). Do not apply too much grease to the bearings!
note Although lube points are provided, the bearings of the vibrator shafts on the AB 200 TV are maintenance-free and therefore do not require grease. Depending on the screed type concerned, the grease nipples are located either directly on the bearing housing (AB 200 screeds, fixed-width (SB) screeds) or on the outer frame from where they are connected to the bearing housings via hoses (AB 500, AB 600 screeds).
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83
VÖGELE Booklet on Paving
3
Parameters Influencing the Paving Process
3.1 General . .................................................................................................................. 3.2 Paving Material ...................................................................................................... 3.3 Paving Parameters ................................................................................................. 3.4 Paver Set-Up ........................................................................................................... 3.5 Relationship Between Tamper Speed and Pave Speed ..................................... 3.6 Recommended Settings for the Compacting Systems ...................................... 3.7 Functions of the Hydraulic Rams for Raising / Lowering the Screed ............... 3.7.1 Screed Float ........................................................................................................................... 3.7.2 Screed Assist .......................................................................................................................... 3.7.3 Screed Freeze . .......................................................................................................................
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85 86 88 89 89 92 93 94 95 95 95
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VÖGELE Booklet on Paving
3.1
3. Parameters Influencing the Paving Process
General
The screed generally floats during the paving process. In other words, the screed changes its position with every change in the balance of forces, for instance due to greater resistance from the paving material, etc. As this is undesirable when paving true to line and level with maximum accuracy, the parameters which may change when paving asphalt must be known so that they can be controlled and kept constant. This naturally cannot be achieved 100% in practice. However, it is extremely important for the user to be aware of all the related conditions in order to produce a high quality pavement. The various influencing parameters and their effect are explained below under the headings "Paving Material", "Paving Parameters" and "Paver Set-up".
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87
3. Parameters Influencing the Paving Process
VÖGELE Booklet on Paving
3.2
Paving Material
3.3
Layer Thickness The larger the layer thickness, the larger the screed planing angle.
Mix Temperature The mix temperature should be constant and high enough to prevent the mix from cooling before it is laid. Paving material that has cooled is harder to compact. The load bearing capacity of the mix, too, depends on its temperature. Feeding the paver with mix must be planned so as to ensure an optimum temperature for paving.
Pave Width The floating behaviour of the screed changes in accordance with the pave width.
Grain Size The maximum grain size should not exceed 1/3 of the layer thickness, otherwise the tamper will act directly on the underlying aggregate and shatter the grains.
Paver Stop The longer the paver stops, the greater the irregularity to be expected in a longitudinal direction.
Stiffness / Load Bearing Capacity The composition of the mix should remain constant throughout the paving job. Properties of the Mix Properties of the mix have an influence on the screed’s floating behaviour. Paving materials with a high bearing capacity confront the screed with a higher resistance than materials of poor bearing capacity. Conveying and compacting systems can be optimally set up to match the type of mix.
88
Paving Parameters
Ambient Conditions Ambient conditions, such as temperature, can influence the mix and change the floating behaviour of the screed.
3.4
Paver Set-Up
Head of Mix in Front of the Screed If there is too large a head of mix in front of the screed, the mix may cool, thus having an adverse effect on both precompaction and the screed‘s floating behaviour. A constant head of mix in front of the screed is a precondition for perfect floating of the screed. The thicker the layer, the greater is the upward force exerted on the screed. Proportional control of conveyors and augers provides for an optimal head of mix in front of the screed.
89
VÖGELE Booklet on Paving
3.4
Paver Set-Up
Tamper Stroke / Tamper Speed The length of the tamper stroke and the tamper speed are factors influencing precompaction of the mix and floating of the screed. On VÖGELE screeds, the tamper stroke can be set to different lengths. The longer the tamper stroke, the higher the precompaction and the compaction depth. For this reason, the length of the tamper stroke should be set in accordance with the layer thickness in order to obtain the smallest possible, positive screed planing angle. A negative screed planing angle may result if the tamper stroke is too long for the layer thickness paved. This can lead to an open-textured, cracked surface structure and uncontrolled levelling resulting in irregularities. Tamper Speed Both the tamper speed and the pave speed have a major influence on precompaction of the mix. This means that the tamper speed must be adjusted in accordance with the pave speed or vice versa. An optimal relationship has not yet been found. For this reason, the values must be individually adjusted until the smallest possible, positive screed planing angle is obtained and wear on the compacting systems is minimized. Rigidity of the Screed When making major changes or one-sided changes to the screed planing angle, torsion of the screed may result.
Screed Freeze Screed Freeze is a briefly activated feature following a paver stop in Screed Float mode. A pressure of about 30 bar is applied to the piston side of the hydraulic rams for raising / lowering the screed in order to prevent it floating up when resuming paving.
90
3. Parameters Influencing the Paving Process
Pave Speed The pave speed determines the impact of the compacting systems on the pavement. Pave speed and head of mix in front of the screed must be well adapted to each other. When paving at a high speed, large quantities of paving material are consumed, which requires good job site logistics for supplying the paver with mix. The pave speed must be selected so as to obtain as constant a supply of mix from the feed lorries as possible. As the pave speed has a major influence on precompaction, it should be set so that the positive screed planing angle is not too large, as this would promote irregularities. The pave speed should, therefore, be set to a value ensuring good precompaction with the screed floating on the mix at a small planing angle. Vibration Frequency When paving thick layers, the vibration frequency has little influence on compaction. Vibration is far more important when paving wearing course, as it promotes the formation of a close-textured, even surface behind the screed. Frequency / Pressure of Pressure Bar(s) The pressure bar(s) are moved up and down by a pulsed hydraulic pressure. These pulses are generated by a rotary valve in the screed at a rate of between 58 and 68 Hz. Hydraulic rams press the pressure bar(s) downwards over the entire pave width. At the end of each pulse, the pressure bar(s) are returned to their original positions by springs acting against the force of the rams. The pressure applied to the pressure bar(s) changes the distance travelled by the pressure bar(s) with each pulse.
91
3. Parameters Influencing the Paving Process
VÖGELE Booklet on Paving
Low Precompaction High Precompaction
Pave Speed 8m/min.
4m/min.
Paving with Automated Grade and Slope Control If automated grade and slope control is used for paving, the desired elevation of the screed can be maintained by increasing the planing angle, but precompaction will not remain constant.
2 - 4
4 - 7
1,500 - 1,800 2,600 - 3,000
90 - 110
AC 22 T
6 - 10
2 - 5
4 - 7
1,000 - 1,400 2,100 - 2,400
70 - 100
AC 22 B
6 - 10
2 - 5
4
1,000 - 1,400 2,100 - 2,400
70 - 100
AC 16 B
4 - 8
2 - 6
4
600 - 1,000 1,800 - 2,100
50 - 80
AC 11 B
4 - 6
3 - 6
4
600 - 800
1,600 - 1,800
50 - 70
AC 11 D
4 - 6
3 - 6
4
600 - 900
1,600 - 1,800
50 - 80
AC 8 D
2 - 4
3 - 6
2 - 4
600 - 900
1,300 - 1,600
50 - 70
AC 5 D
2 - 4
3 - 6
2 - 4
600 - 900
1,200 - 1,500
Off
SMA 11
4 - 6
3 - 6
4
600 - 1,500 1,600 - 1,800
50 - 80
SMA 8
2 - 4
3 - 6
2 - 4
600 - 1,500 1,300 - 1,600
50 - 70
SMA 5
2 - 4
3 - 6
2 - 4
600 - 1,500 1,200 - 1,500
Off
Asphalt: Combined Base/ Wearing Course
AC 16 TD
8 - 16
2 - 6
4
1,200 - 1,800 2,200 - 3,000
80 - 110
Asphalt: Thin Layer
1 - 3
3 - 10
2
500 - 1,400 1,000 - 1,200
Off
Asphalt: Binder Course
Asphaltic Concrete: Wearing Course
Pave Speed 8m/min.
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4m/min.
Pressure Bars Pressure (bar)
10 - 60
After Compaction by Rolling When the roller passes over the mix, the amount of extra compaction will differ on account of varying precompaction and result in irregularities in the surface.
Vibrator Speed (rpm)
AC 32 T
Asphalt: Base Course
Tamper Speed (rpm)
Tamper Stroke (mm)
4m/min.
Pave Speed (m/min.)
8m/min.
Tamper speed and pave speed are very strongly dependent on one another. Any change in pave speed without changing the tamper speed and position of the screed tow point rams will affect precompaction of the mix. If the pave speed is increased without simultaneously increasing the tamper speed, the load bearing capacity of the mix will be reduced and the screed lay a thinner layer at a steeper planing angle.
Type of Pavement
Layer Thickness (cm)
While paving, when screed tow point rams are not changed in position, an equilibrium of forces comprising pave speed, screed weight and tamper speed is established. If any one of these parameters changes, this immediately affects the screed‘s floating behaviour.
3.6 Recommended Settings for the Compacting Systems
Material
3.5 Relationship Between Tamper Speed and Pave Speed
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3. Parameters Influencing the Paving Process
VÖGELE Booklet on Paving
3.7
Functions of the Hydraulic Rams for Raising / Lowering the Screed
3.7.1
Screed Float
Normally, mix is paved with the screed in Screed Float mode. In other words, the piston-side and rod-side valves operating the hydraulic rams for extension/retraction of the screed are open towards the hydraulic oil tank for free extension and retraction of the screed.
3.7.2
Screed Assist Pressure
Screed Float
Screed Assist
If the bearing capacity of the mix is poor, the screed will not reach the desired elevation even when set to a large planing angle. The Screed Assist function allows pressure to be applied separately to the right and left-hand hydraulic rams from below. This pressure counteracts the screed weight and allows it to float up in accordance with the magnitude of the pressure.
Attention! Do not use for wearing course!
3.7.3
Screed Freeze Pressure
94
Screed Freeze
The Screed Freeze function is activated automatically following a paver stop in Screed Float mode. The valves activating the hydraulic rams for raising / lowering the screed are closed on both the piston and the rod sides, thus briefly suspending the Screed Float mode in order to prevent irregularities in the pavement when resuming paving.
95
VÖGELE Booklet on Paving
96
4
Recommendations for Paving / Points to Note
97
4.1 4.1.1 4.1.2 4.1.3 4.1.4 4.1.5 4.1.6 4.1.7 4.1.8 4.1.9 4.1.10 4.2 4.2.1 4.2.2 4.2.3 4.2.4 4.2.5 4.2.6 4.2.7 4.2.8 4.3 4.3.1 4.3.2 4.3.3 4.3.4
Before Starting ....................................................................................................... 98 Fundamentals . ...................................................................................................................... 98 Setting the Layer Thickness ............................................................................................. 100 Weather Conditions when Paving Asphalt . ................................................................. 104 Requirements Made on the Roadbase and its Surface ............................................. 105 Augers and Limiting Plates for the Auger Tunnel on an Extending Screed ......... 108 Definition and Preparation of the Route ...................................................................... 110 The Optimal Sensor for Every Paving Application . .................................................... 111 Ordering Asphalt from the Mixing Plant on Call . ....................................................... 122 Preparing the Reference for Grade and Slope Control .............................................. 123 Correct Positioning of the Grade and Slope Sensors ................................................. 124 During the Paving Process .................................................................................. 125 Positioning the Paver . ....................................................................................................... 125 Head of Mix in Front of the Screed . ............................................................................... 126 Joints in Asphalt Pavements ........................................................................................... 127 Expansion Joints .................................................................................................................. 131 Paving “Hot to Cold” .......................................................................................................... 132 Paving “Hot to Hot” ............................................................................................................ 133 Duties of the Paving Team during the Paving Process .............................................. 134 Tools for Continuous Verification of the Paved Result . ............................................. 136 After Paving .......................................................................................................... 138 Subsequent Compaction by Rolling .............................................................................. 138 Rules for Rolling and Avoiding Errors ............................................................................ 142 Measurement of Density and Surface Accuracy ......................................................... 143 Cleaning, Daily Maintenance and Completion of the Job Site . .............................. 144
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VÖGELE Booklet on Paving
4.1
Before Starting
4.1.1
Fundamentals
4. Recommendations for Paving / Points to Note
Before starting work, the minimum and maximum pave widths should be established and the paver set up accordingly. The paving sequence should be coordinated with the other teams on site in order to assure the supply of material and prevent the hot mix being driven over too soon. The lorries delivering the material must be organized in such a way as to ensure a continuous supply of mix with as few paver stops as possible. Contact the people responsible at the mixing plant to ensure that mix can be supplied as planned. Check the paver‘s serviceability (filling levels, electrical and hydraulic functions, etc.). The tarpaulin covering the mix in the lorry should only be removed shortly before the hot mix is transferred to the paver so that it cannot cool.
98
99
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1.2
Setting the Layer Thickness
Due to the numerous parameters influencing the paving process, it has hitherto been impossible to develop a formula supplying exactly the right value for setting the tow point rams for a required layer thickness. When working with Extending Screeds, the general rule is: layer thickness in cm + (50 to 100%) yields roughly the values to be set on the paver’s scales for layer thickness. The settings must be checked after paving the first few metres and corrected as required.
H = Layer Thickness S = Specified Thickness W = Amount of Compaction by Rolling
H
W
S
The screed only precompacts the mix. Final density is achieved through subsequent compaction by rolling. Rollers compact the mix by an amount (W) somewhere between layer thickness (H) and the specified thickness (S). (W) is the amount of subsequent compaction by rolling and must be taken into account when setting up the screed.
100
H H = Layer Thickness
Since the screed‘s floating behaviour means that it would have to travel a certain distance before reaching the layer thickness, it is recommended to put the screed down on timbers or uniformly spread material level with the layer thickness.
101
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1.2
Setting the Layer Thickness
Scale for Layer Thickness
α H
α = Planing Angle H = Layer Thickness
The planing angle α results when setting the layer thickness H + (50 to 100%) via the tow point rams using the layer thickness scales. The fishplates are in their normal positions. The layer thickness should be checked immediately when starting paving so that the position of the tow point rams can be corrected if necessary.
102
S S = Specified Thickness
After rolling, the surface must be checked to ensure it has the specified thickness. If not, the layer thickness must be corrected again until the correct result is obtained after rolling.
103
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1
Before Starting
4.1.3
Weather Conditions when Paving Asphalt
4.1.4
Requirements Made on the Roadbase and its Surface
On the majority of job sites, weather conditions can only be taken into account to a very limited extent because of the tight scheduling. However, this can give rise to problems when paving hot mix. In very cold conditions and if the distance between mixing plant and road paver is relatively long, the temperature of the mix may well have dropped to the lower limit permissible for paving.
D epending on the bitumen type used,
it will be difficult for the rollers to achieve the specified final density if the temperature of the mix is below 120 °C when dumped from the feed lorry into the paver’s material hopper.
S ince the ambient temperature causes the asphalt to cool more rapidly, wearing course should not be paved at temperatures below 3 °C or better still below 6 °C.
Binder course contains more coarse
grains which retain heat, with the result that such layers can still be paved at temperatures around zero.
104
I t may even be possible to pave base course at temperatures as low as -3 °C, but be sure that the roadbase is always free from ice and snow.
T he decision whether or not paving is possible should not only be based on air temperature: the temperature of the base must also be taken into account, as a cool base will similarly cause the mix to cool more rapidly.
The surface of a non-bonded roadbase
Paving on a wet or puddled base is not recommended. Water vapour may form under the paved layer when the hot mix comes into contact with moisture. Since this vapour strives to escape upwards, it produces cavities which will impair the bearing capacity and precompaction of the mix and may also have a negative effect on the screed‘s floating behaviour.
It is advisable to hand over the roadbase
F ormation of vapour is normally unlikely when paving fresh emulsion, as the boiling point is very much higher.
must be level, stable and perfectly compacted so that the asphalt pavement uniformly retains its load bearing capacity for a long time after being paved. with official acceptance guaranteeing that the load bearing capacity, elevation, evenness, as well as longitudinal grade and transverse slope meet with the requirements specified in the planning.
It is also important to check the height
of any shafts, drains or hydrants so that they cannot obstruct the paving process and remain accessible afterwards. The surface must be cleaned by
sweeping or with compressed air or a jet of water in order to ensure good bonding between pavement and roadbase. The surface must then be sprayed with
bitumen emulsion or a tack coat so that the freshly laid mix bonds with the base.
When paving an asphalt layer on
a bonded roadbase, it should also be level, stable and compacted, just like the non-bonded roadbase. Preliminary level regulating measures may be necessary if the roadbase is very uneven.
105
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1.4
Requirements Made on the Roadbase and its Surface
Level Regulating Measures Before Placing Base Course The layer thickness should remain constant over the full pave width to the greatest possible extent. If it does not, it is recommended to level out major differences beforehand in order to achieve uniform precompaction and uniform extra compaction by rolling. The type of mix used for such level
Filling Depression
regulating purposes should be adapted to the layer thickness. This material can be laid either by hand
or with the paver.
Layer Thickness and Grain Size of the Mix
Attention! The layer thickness should be at least three times the largest grain size in the mix!
If this is not the case, grains may be crushed and the screed begin to bounce due to the impact of its compacting systems. If the colour of the crushed stone appears on the surface, this indicates that grains have been destroyed. This is quickly revealed, as all constituents in the mix are normally coated with black bitumen. In addition, the screed may be unable to maintain the required elevation and the layer thickness will increase.
Good precompaction of the level
regulating layer is important.
Raising Level of Shoulder
106
107
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1.5
Augers and Limiting Plates for the Auger Tunnel on an Extending Screed
In order to save power, the head of mix in front of the screed should be uniform and constant. This is ensured by strike-off plates and limiting plates for the auger tunnel which should be adapted to the pave width. It also prevents segregation of the mix and helps it to cool more slowly.
Strike-off Plate
Horizontal Bracing Limiting Plate for Auger Tunnel
End Plate
Horizontal / Vertical Bracing
Strike-off Plate Limiting Plate for Auger Tunnel
End Plate
Bolt-on Extension
The following page contains examples of correct auger extension and installation of limiting plates for the auger tunnel.
Strike-off Plate Limiting Plate for Auger Tunnel
Bolt-on Extension Horizontal / Vertical Bracing End Plate
TIP! The augers and limiting plates for the auger tunnel should reach up to within 20cm of the end plate.
108
Bolt-on Extensions
Bolt-on Extensions
109
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1
Before Starting
4.1.6
Definition and Preparation of the Route
4.1.7
The Optimal Sensor for Every Paving Application
On larger job sites or when working with a Fixed-Width Screed built up to a large width, it is advisable to work with Automated Steering Control, since the reference and the steering guide may be beyond the operator‘s field of vision. If Automated Steering Control is installed, it steers the paver parallel to the reference line. This relieves the paver operator, allowing him to concentrate his full attention on other paving tasks.
Airports (New Construction)
Racing Tracks (Pavement Rehabilitation)
Places and Large Areas
•••
•
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•
••
•
••
••
••
•••
••
•••
Racing Tracks (New Construction)
Motorways
•• ••
Rural Roads • •••
Roundabouts •••
Traffic Calmed Areas •••
Municipal Roads •••
Mechanical Variable Mechanical Grade Sensor
Stringline Mode
Ground Mode
Averaging Beam
Slope Sensor
•••
•••
•••
•
•
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•
••
•••
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•
•
Non-Contacting, Acoustic Single-Cell Sonic Sensor Multi-Cell Sonic Sensor
Stringline Mode
•••
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•••
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Ground Mode
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Big MultiPlex Ski
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Non-Contacting, Optical Laser Receiver
3D Machine Control Systems NAVITRONIC Plus® and NAVITRONIC® Basic
••• highly recommended
110
Application
Highways (New Construction)
Since the steering guide prevents excessive steering movements by the paver, it also helps the drivers of the feed vehicles dump the mix into the middle of the paver‘s material hopper.
Sensor
Airports (Pavement Rehabilitation)
A steering guide should be installed in the front of the paver to help the machine operator follow the route of the road as accurately as possible. The steering guide helps steer the paver parallel to a reference line so that the screed operators do not constantly have to correct the paver‘s steering movements by extending and retracting the screed in order to obtain a continuous pavement edge.
•• recommended
• suited
111
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1.7
The Optimal Sensor for Every Paving Application
Variable Mechanical Grade Sensor For direct tracing of a reference
(stringline, base etc.).
Multi-Cell Sonic Sensor N on-contacting
tracing of a reference (stringline, base). For large obstacles detected by the sensor, an internal filter is provided.
A rotary laser produces an accurate laser plane.
The plane serves as a reference for the laser receiver.
Laser Receiver A precise plane serves as reference for the laser
Slope Sensor Indication of the actual slope on the
handset. Input of specified slope via the handset. Values can be changed while paving. Tolerance range ± 0.05%. For pave widths up to 6m. Sensor measuring range ± 10%.
112
receiver. This reference plane is generated by a rotary laser. It is independent of ground conditions. The large measuring range of 22cm allows the laser receiver to be used on bases with major irregularities without the height of the rotary laser or laser receiver having to be adjusted. Uninterrupted measurement is assured by mounting the transmitter and laser receiver at a height of up to 4.5m. Depending on the type of rotary laser used, the paver can work within a radius of up to 200m from the laser transmitter.
113
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1.7
The Optimal Sensor for Every Paving Application
Single-Cell Sonic Sensor for grade control.
Metal bow fitted at a fixed distance to the sensor cell, determines value for temperature compensation.
Single-Cell Sonic Sensor Non-contacting scanning in order to trace a reference. A sound cone is used for scanning. This ensures 1:1 transmission of the reference height without formation of mean values. Its compact size makes the sensor ideal for use on confined job sites or roads with numerous tights bends. It is also recommended in all those cases where precise copying of the reference is essential.
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Big MultiPlex Ski Also levels out long irregularities in the base. 3 sonic grade sensors scan the reference in non-contacting operation. Easy operation. Easily mounted on the screed arm or screed side plate. Can be used for various jobs, also in bends. Variable beam length from 6.5m to 13m. Large vertical measuring range from 250mm to 650mm.
Modular beam up to 13m long.
3 Multi-Cell Sonic Sensors with 5 sensor cells each.
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VÖGELE Booklet on Paving
4.1
Before Starting
4.1.7
The Optimal Sensor for Every Paving Application
4. Recommendations for Paving / Points to Note
Short Ski Length 0.3m
TIP! Should only be used for tight bends or for deliberately copying irregularities from the base.
Long Ski Length 0.8m
TIP! Big MultiPlex Ski By arranging 3 sonic grade sensors in a row, it is possible to tap the physical reference at several points lying far apart from each other. Based on the values picked up by the sensors, NIVELTRONIC®, the VÖGELE System for Grade and Slope Control, calculates a virtual reference. In other words, this system offers higher accuracy than a single sonic grade sensor.
116
Used when paving large bends or straight sections.
Averaging Beam Length 7m
TIP!
TIP!
Ideal for levelling out long irregularities when an absolute reference is not available.
Used when paving surfaces requiring high evenness.
117
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
118
4.1
Before Starting
4.1.7
The Optimal Sensor for Every Paving Application
Sonic Grade Sensor (Stringline Mode)
Laser Receiver
Five sound cones are emitted when using the sonic grade sensor in stringline mode and the shortest reflected signal (from the stringline) is sent to the system for grade and slope control. The sensor can be mounted at any height between 25cm and 65cm above the stringline. The desired height is confirmed by NIVELTRONIC® as a specified value.
The laser unit generates a plane with its rotating laser beam. This plane is picked up by the laser receiver. If the laser receiver moves out of the plane, signals for correction are sent to the system for grade and slope control. The plane generated by the laser beam is used as a virtual reference for the elevation of the screed.
Attention!
TIP!
Referencing the base in stringline mode can lead to considerable fluctuation in the process of grade and slope control, as in stringline mode a mean value is not calculated. Sonic signals may change direction as a result of wind or other physical factors.
Used on job sites with constant grade and slope.
119
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1.7
The Optimal Sensor for Every Paving Application
NAVITRONIC Plus® Non-contacting grade and slope control and navigation system. Real 3D machine control system for road pavers. Digital planning data can be adopted. Ideal for large areas and motorway construction. Control precision within the millimetre range
guarantees maximum accuracy. Open interface to connect external 3D positioning systems
from renowned manufacturers.
Grade and slope control (control of layer thickness and transverse slope).
Fully automatic control of the screed‘s position.
NAVITRONIC Plus®, the 3D Control System for Grade and Slope Control and Navigation of Road Pavers, extends NIVELTRONIC Plus® into the third dimension. NAVITRONIC Plus® makes it possible to automatically control not only grade and slope, but also pave width and direction of motion according to a route‘s digital design data. The non-contacting System for Grade and Slope Control and Navigation combines with positioning systems of many renowned manufacturers. For positioning, laser-based total stations are available as well as mmGPS.
TIP! Fully automatic control of the paver‘s direction of motion.
120
Used on job sites where a reference is not available (kerbstone, gutter etc.) or when building multi-lane areas (roads, squares, runways etc.).
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4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1
Before Starting
4.1.8
Ordering Asphalt from the Mixing Plant on Call
4.1.9
Preparing the Reference for Grade and Slope Control
The actual production process starts when the asphalt is called by the job site. So that production can be planned, it is advisable for an order to be sent to the mixing plant from the job site beforehand. This ensures that asphalt is available in the required quality when it is needed.
0% Transverse Slope
However, the planned sequence of operations can always change at short notice, e.g. due to weather conditions or machine failures on site or in the mixing plant. Constant communication is therefore very important so that both parties can react to such unforeseen changes. The asphalt produced in the mixing plant is either collected by the customer directly or delivered to the job site by the asphalt manufacturer. However, the details concerning transport are always decided by the customer. These details relate to the number and size of the delivery vehicles. Transport capacity must be matched to:
the capacity of the mixing plant,
the laydown rate of the paver,
the distance from the job site, and
the traffic conditions.
The reference from which actual values are picked up is normally outside the pave width. Since the bracket carrying the grade sensor is rigidly connected to the screed, any change in slope will also influence the elevation on the reference side. The magnitude of this influence depends on the distance between screed and reference and may make it necessary to correct the elevation.
Example: -2% Transverse Slope
0.5m
A continuous supply of asphalt to the job site is assured if all these points are taken into account. This is the responsibility of the site manager and the head of the paving team. dh
Change in Grade (dh) =
Slope [%] 100
x Distance [cm] = 1cm
Example Actual values are picked up from a reference with a transverse slope of 0%. Then the slope changes to -2%. If this change is not taken into account for referencing, then the layer would become 1cm too thick given a distance of 0.5m between the screed and the reference.
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123
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.1
Before Starting
4.1.10 Correct Positioning of the Grade and Slope Sensors osition of Sensors for Controlling the Floating Screed (Example: Referencing from Stringline) P The rules apply to all sensors for referencing. Right! Optimal sensor position. Even paving, true to line and level.
4.2
During the Paving Process
4.2.1
Positioning the Paver
Connect the screed consoles and grade and slope control system to the paver.
Heat the paver and screed to operating temperature.
Under the screed, place a flat iron or timber with the same thickness as the
required layer thickness plus the amount of subsequent compaction by rolling.
Lower the screed onto the flat iron or timber.
Set the screed planing angle.
Set and switch on automatic grade and slope control. Work with manual control,
if necessary.
Wrong! The sensor is located too far to the rear. The actual elevation of the screed‘s trailing edge is determined fairly accurately, but there is no time left to correct the layer thickness if necessary.
The feed vehicle docks onto the paver.
The paver is filled with mix; set the sensors for conveyors and augers.
Set the compaction systems.
Set the pave speed.
Actuate the joystick for traction and the remaining functions run in automatic mode.
Consequence: Irregularities in the pavement.
Caution! The sensor is located too far to the front. The screed tow point follows parallel to the reference, but information on the screed‘s floating behaviour and the actual layer thickness are only taken into account to a marginal extent. Consequence: Even paving, but not precisely true to line and level.
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125
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.2
During the Paving Process
4.2
During the Paving Process
4.2.2
Head of Mix in Front of the Screed
4.2.3
Joints in Asphalt Pavements 1
The head of mix in front of the screed should be uniformly spread over the full pave width. The use of limiting plates for the auger tunnel and of strike-off plates is strongly recommended.
Rules A joint describes the connecting seam between two adjacent strips (longitudinal joint). Joints are found when working with several pavers in echelon (“hot to hot“) or when paving a single lane alongside an existing lane (“hot to cold“). A transverse joint is installed when resuming work on the previous day‘s section or between paving sessions. In all cases, the two areas must be durably connected to prevent surface water seeping into the pavement.
Longitudinal Joints Mix is not spread adequately from the inside outwards, with the result that there is too much mix in front of the screed’s basic unit: Reduce pave speed / increase
auger speed. Check / adjust position of sensor
for augers. Adjust auger height.
The conveyors do not deliver sufficient mix: Increase conveyor feed rate. Reduce pave speed. Fit limiting plates for auger tunnel. Check / adjust position of sensor for augers. Adjust auger height.
Paving “Hot to Hot“ Paving with two or more pavers working in echelon is ideal for an integral bond between asphalt strips. Points to be noted: The distance between the individual pavers should be kept as short as possible so that the joint face of the first strip is still sufficiently hot. The first rollers following each paver should be of the same size. The rollers start rolling towards the joint from the outer pavement edge inwards. Compaction ends approx. 15cm beside the longitudinal seam on either side. The joint is then the last strip to be compacted by the rollers. This way a tight bond between the pavement strips is obtained.
Road Axis
Asphalt Wearing Course Asphalt Binder Course Asphalt Base Courses
Longitudinal Joint Joints should be offset in the individual pavement layers and produced with oblique faces.
1 Text and diagrams on pages 127 - 130 in accordance with the asphalt LEITFADEN: Ratschläge für den Einbau von Walzasphalt (Asphalt Manual, Guidelines for Paving Hot Mix), published by DAV Deutscher Asphaltverband e.V. (German Asphalt Association), 2nd edition, July 2007, pages 35 - 40.
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127
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.2
During the Paving Process
4.2.3
Joints in Asphalt Pavements
Longitudinal Joints
Transverse Joints
Paving “Hot to Cold“ If paving needs to be carried out in half-road width, particular attention must be paid to the joint area.
Transverse joints are installed at the end of the day or when paving is interrupted for a longer period of time.
Points to be noted: The first point to be noted as a matter of principle is that the joint area should NOT be located directly under the future road marking or wheel track. When paving the first strip, the joint face (= contact area) must be properly designed. The contact area should be angled at 70 - 80 degrees. This yields a larger contact area in relation to the layer thickness than would be obtained with a vertical face. The oblique face is shaped with bevel irons fitted to the paver or an edge trimming equipment fitted to the roller. To obtain a perfect bond between the pavement strips, the contact area should be pre-treated as follows (see diagram on page 132): 1. The contact area must be thoroughly cleaned, including the area of the adjacent base, if necessary. 2. Spray or coat with sufficient binder. This is done with hot or cold compound.
How to proceed: Drive the paver from the job site. Remove asphalt manually in areas with insufficient layer thickness, form a straight transverse edge. Fit a strip of wood corresponding to the layer thickness. Spread some sand onto the base in front of the transverse edge (preparation for a ramp). Use some remaining mix to build a ramp by hand on the thin layer of sand. Compact the entire area including ramp by rolling. Before resuming work, remove the ramp, the strip of wood and the sand. Using a straightedge, check the old surface for good evenness in the longitudinal direction. If not even enough, it must be cut back further. Clean the ramp area and spray with tack coat. Compact the joint area as described in the section “Hot to Cold”.
When paving and compacting the second strip, the following must be noted: Pave the second strip with a slight overlap (2 - 3cm) and take the amount of subsequent compaction by rolling into account. If the overlap is too small or non-existent, this would result in a lack of mix in the joint area, which would in turn lead to poor compaction and, later on, to road failure in the area of the joint. If the overlap is too large, the paver would ride up on the first strip, shattering the grain in the overlapping area and resulting in insufficient compaction of the joint area. Before starting compaction by rolling, the overlapping mix must be pushed back into the area of the second strip.
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129
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.2
During the Paving Process
4.2
During the Paving Process
4.2.3
Joints in Asphalt Pavements
4.2.4
Expansion Joints 2
Producing a Longitudinal Joint
Rules
Splash guard, if necessary Bituminous mix
Expansion joints are mandatory when paving alongside an existing area with dissimilar properties. This is the case with: Channels (concrete, paving stones) Kerbs (concrete, natural stone)
Overlap (2 - 3cm) Push back
Concrete pavements Walls Pavement fittings
Joints can be constructed either by shaping and sealing or with the aid of joint tape.
paved by the paver
Properties of the Joint Face
Roller
Last but one roller pass if finished strip cannot be driven over
Last roller pass if finished strip cannot be driven over
The joints must be: Equal to the full thickness of the wearing course Vertical Clean and dry First pass with the roller
Sealing Joints The joint gap can be formed in different ways: As a recess By cutting By milling
Roller
Roller
How to proceed for sealing joints: Remove dirt, clean with compressed air, wash if necessary. Dry the gap of the joint, e.g. with hot air. Apply prime coat and let it dry. Carefully prepare the sealing compound. The manufacturer‘s instructions for the sealing compound must be observed. Pour with a lance or can.
2 T ext on page 131 in accordance with the asphalt LEITFADEN: Ratschläge für den Einbau von Walzasphalt (Asphalt Manual, Guidelines for Paving Hot Mix), published by DAV Deutscher Asphaltverband e.V. (German Asphalt Association), 2nd edition, July 2007, pages 41 - 42.
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131
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.2
During the Paving Process
4.2
During the Paving Process
4.2.5
Paving “Hot to Cold”
4.2.6
Paving “Hot to Hot”
Paving “hot to cold” means that hot asphalt is laid alongside an existing, cold asphalt layer. The edges of the cold asphalt layer must be evened and cleaned in order to obtain an optimal bond between the two layers. A rough contact surface with a suitably thick binder course is helpful here.
For paving “hot to hot“, the pavers work alongside each other in echelon. Subsequent compaction by rolling takes place across the full width. The supply of mix should be organized
so that all pavers can work at the same speed and the distance between pavers does not become too large. The temperature differences between the adjacent lanes will then be roughly the same when subsequently compacted by rolling.
When paving wearing course, joint tape
is affixed to the edge of the cold asphalt. It melts in the heat of the hot asphalt and prevents water penetrating into the joint in the long term.
Hot Asphalt
than the adjacent layer by the amount of subsequent compaction by rolling, in order to obtain a seamless transition when finally compacted. Amount of Compaction by Rolling Longitudinal Joint 1 Strip (cold) st
Hot Asphalt
Hot Asphalt
The screed’s end plate should be set Cold Asphalt
2nd Strip
pavers should preferably use the same screeds to ensure identical precompaction with the same settings for the compacting systems over the full pave width. Both strips will then be precompacted by the same amount and can be paved side-by-side without producing a step between them.
The
The hot asphalt layer must be thicker
so that material does not overlap with the previous layer, as this could lead to crushed grains and distort the roller drums when subsequently rolled. For multi-layer pavements, the joints
Base Course
Wearing Course Binder Course
between the individual layers should be offset to achieve a better bond between the layers.
Attention! The amount of subsequent compaction by rolling must also be taken into account in the area of the joint between the two strips. Otherwise a transverse slope of imperfect smoothness results and surface water cannot run off as planned.
132
133
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.2
During the Paving Process
4.2.7
Duties of the Paving Team during the Paving Process
Feeder Operator Ensure that the conveyor is correctly positioned (direction and height) so that mix is transferred to the paver‘s material hopper. Ensure that the paver‘s material hopper is not overfilled. The mix must be transferred to the material hopper without obstruction. Ensure that the feeder is filled continuously. The feeder must be operated correctly. Check hazard areas. Prepare the feeder for the job and clean it after each job.
Paver Operator E nsure that the paver‘s material hopper is constantly filled. Correct steering as required for the project. Ensure a good head of mix in front of the screed and that the auger is at the correct height.
T he paver must be operated correctly. Look out for people in the hazard area. Check the pavement behind the paver at regular intervals. Regularly check the pavement after rolling (uniform, closed-textured surface structure). Prepare the paver for the job and clean it after each job.
Screed Operator Operate the screed and change any screed settings as required. Ensure correct grade and slope control. Regularly check the layer thickness with a yardstick or thickness measuring instrument. Ensure that the side plate is positioned correctly. Maintain the correct pave width (by extending and retracting the screed accordingly). Take note of all people and vehicles in the immediate hazard area. Note the screed planing angle and surface texture of the asphalt pavement. Prepare the screed for the job and clean it after each job.
Control Ensure that the mix is delivered correctly (temperature, homogeneity, material specification, quality). Call the required asphalt quantities from the mixing plant. The amount must be reduced or cancelled if paving is interrupted. Accept and check the material traveller tickets. Compare the delivered quantity with the paved quantity. Plan and assure a smooth sequence of operations: from delivery of the material through transfer into the paver to work of the paver and screed operators. Ensure and continually check that all members of the paving team comply with the occupational safety requirements. Check the pavement behind the paver and behind the rollers and optimize it if necessary.
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135
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.2
During the Paving Process
4.2.7
Tools for Continuous Verification of the Paved Result
Two spatulas for cleaning, e.g. for the leading edge of the screed.
30m measuring tape and two yardsticks.
Wedge for determining the surface accuracy in millimetres under the 4m straightedge.
4m folding straightedge for measuring the longitudinal surface accuracy and desired transverse pavement profile during the paving process.
Non-contacting thermometer to obtain a quick rough guide as to the mix temperature or pavement temperature at any time.
Marker spray in various colours for marking areas of critical importance for grade and slope control, e.g. manholes, etc.
Digital spirit level for checking the correct transverse pavement profile (it is placed on the 4m straightedge).
136
Asphalt thickness measuring instrument for checking the layer thickness placed during the paving process.
137
VÖGELE Booklet on Paving
4.3
After Paving
4.3.1
Subsequent Compaction by Rolling3
Only a few years ago, the prevailing opinion was that compaction played a relatively insignificant part in the construction process. Today, we know that high-quality compaction helps to cut costs and decisively extends the road‘s useful life. Freshly placed asphalt must be compacted in order to obtain a denser structure by rearranging the grains and reducing the number of voids filled with air and water. In this way, all layers and strips are combined to form a compact structure. This results in better pressure distribution inside the road structure, allows shearing forces from traffic to be absorbed and dissipated more effectively and consequently extends the road‘s service life. Many different rollers can be used to compact asphalt. They differ not only with regard to their weight and the width of their drums, but also as regards their type of steering and their respective compaction systems.
4. Recommendations for Paving / Points to Note
Tandem Rollers A tandem roller has two smooth drums, each of which is fitted with an internal vibratory or oscillation unit to produce a better compacted result. In addition to surface pressure, the roller can also apply dynamic energy to the asphalt course. Hydrostatic drives are provided for traction and vibration. Since tandem rollers are primarily designed to compact asphalt, they include a water sprinkler system for the drums to prevent fresh asphalt adhering to them. Crab steering is a special feature of tandem rollers. The rear drum is shifted to the right or left in this mode. This overlapping increases the rollers‘ working width (by up to 100% in the case of HAMM rollers). Tandem rollers are further differentiated according to their type of steering. Articulated rollers are jointed in the middle of the roller. Rollers with four-wheel steering on the other hand have two pivot points via which each drum can be steered separately or jointly in opposite directions (analog steering).
Principle of articulated steering: the longitudinal axes of the front and rear chassis are shifted in relation to one another when the tandem roller is steered, but the drums themselves remain rigid in their frames. (Middle diagram: crab steering activated.) 3 A ll text on pages 138 - 141 in accordance with: Hamm AG, Verdichtung im Asphalt- und Erdbau (Compaction of Asphalt and Earth Works), Tirschenreuth 2008 (company publication), pp. 7, 18 et seq., 38-45.
138
139
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.3
After Paving
4.3.1
Subsequent Compaction by Rolling
Rubber-wheeled Rollers Rubber-wheeled rollers are static compactors, i.e. they compact the asphalt by applying their weight, but they also make use of the wheels‘ kneading and flexing work. This ensures that the pores are effectively closed. Their depth effect depends on the wheel load, tyre pressure and rate of advance. Due to the limited stability of asphalt layers at the start of the compaction process, they must be precompacted by rubber-wheeled rollers. The rubber wheels‘ large contact area is an advantage here. It compresses the asphalt and prepares it for further compaction by tandem rollers. Rubber-wheeled rollers are otherwise mainly used on thin, easily compacted asphalt layers and on loamy soil.
Three-wheel Rollers A three-wheel roller has one drum centred at the front and two lateral drums at the rear. All three drums are smooth. The strips followed by these three drums overlap. The rollers are driven by a diesel engine. The performance of a three-wheel roller is based solely on the high static linear load resulting from its high weight and small drum widths. Although its depth effect is relatively modest, it achieves very good evenness. These rollers are therefore particularly suitable for smoothing asphalt wearing courses and are used wherever water or bitumen would be drawn to the surface as a result of dynamic compaction.
140
Combi Rollers Combi rollers are used above all for compacting asphalt. They combine the advantages of dynamic compaction systems with the kneading and flexing action of rubber-wheeled rollers. Combi rollers have a vibratory or oscillating drum on their front axle. The rear axle is fitted with rubber-tyred wheels. These machines are available as articulated and all-wheel drive rollers. Combi rollers display better gradeability than the tandem rollers with their dynamic compaction and also produce a better bond between layers, as well as better pore closure.
In addition to static compaction, rubber-wheeled rollers also seal the surface through their kneading and flexing action. This makes them eminently suitable for smoothing the final, compacted asphalt pavement.
141
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.3
After Paving
4.3
After Paving
4.3.2
Rules for Rolling and Avoiding Errors
4.3.3
Measurement of Density and Surface Accuracy
1. Compaction must be started as soon as possible, as the asphalt can only be compacted while hot. 2. T he powered drum must be positioned facing the paver to prevent unrolled material accumulating in front of the drum. This would lead to transverse cracking in the surface. The only exception to this rule is when working on a very steep slope. 3. Drums must be carefully sprayed with water to prevent freshly laid mix sticking to them.
Test Core
Radiometry
The pavement must have a certain density in order to display the specified load bearing capacity. The density is measured either in the laboratory on the basis of a test core or directly on site by radiometry (Troxler probe).
4. Vibration must never be switched on while the roller is stationary, as the drums would leave a permanent imprint in the pavement surface. 5. Rollers must be started and reversed gently or electronic speed control used to prevent material accumulating in front of the drums. Heavy rollers in particular must not come to a standstill. 6. Vibration should not be switched on until the roller is in motion. It should be switched off when reversing or automatic control should be used. Since the roller reduces speed as it reverses to a standstill and then accelerates in the opposite direction again, the vibration would produce a greater effect in this area than in the surrounding area, thus resulting in an uneven pavement surface. 7. Always start at the lower edge on a lane with transverse slope and move towards the higher edge.
Surface accuracy must be checked on site during and after the paving process using a 4m straightedge and test wedge. The tolerance should not exceed 2mm.
8. The roller should preferably only be relocated and steered on mix which has already been compacted in order to prevent material accumulating in front of the drum. 9. Never stop the roller on hot mix, as the drums may be pressed into the pavement by the weight of the roller. 10. The roller should be parked diagonally to the direction of paving. If the drums leave marks in the pavement surface, this will reduce riding comfort to a lesser extent than if the marks run at right angles to the road.
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143
4. Recommendations for Paving / Points to Note
VÖGELE Booklet on Paving
4.3
After Paving
4.3.4
Cleaning, Daily Maintenance and Completion of the Job Site
10 Steps after Paving: Time Required approx. 30 Minutes Step 1: Before the paver is supplied with material from the last feed lorry, switch off screed heating and spray the material hopper and auger with cleaning agent. Step 2: Before raising the screed, switch off automatic grade and slope control and set both screed tow point rams to the same height.
Step 3:
Raise the screed and set it down on the locking bolts.
Step 4:
Empty the material hopper and conveyor tunnel.
Step 5: Extend the screed extensions completely and select operating mode "N" (neutral). Step 6: Clean those parts of the tractor unit and screed which cool rapidly (side plates, deflector plates, centre auger box, limiting plates for the auger tunnel and push-rollers).
TIP! Step 7:
Select "Positioning" mode and activate "Cleaning".
After Work on the Job Site The following tasks should also be performed when the work on site is complete:
Step 8: Spray all paver parts in contact with the mix with cleaning agent (tamper must be sprayed from the back, pressure bars from above).
1. Technical check of the machine. 2. Check that the machine has been properly parked. 3. Protect the machine against vandalism.
Step 9: Retract the screed‘s extending units, switch off the engine and the ignition.
Step 10: Remove the sensors for grade and slope control, as well as the screed consoles. Cover the paver operator‘s console to prevent it being vandalized.
144
4. Add up the delivery notes for mix for the day just ended. 5. C heck that everything has been prepared on site for the next working day (is sufficient fuel available, has asphalt been ordered from the mixing plant for the next day, etc.).
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VÖGELE Booklet on Paving
5
Imperfect Paving
5.1 Systematic Elimination of Paving Errors ........................................................... 5.2 Paving Problems / Paving Errors ........................................................................ 5.2.1 Irregularities when Passing over Mix . ........................................................................... 5.2.2 Pavement Irregularities due to Large Screed Planing Angle ................................... 5.2.3 Hump Formed when Resuming Paving ........................................................................ 5.2.4 Short Irregularities in Transverse Direction . ................................................................ 5.2.5 Periodic Irregularities in Longitudinal Direction . ....................................................... 5.3 Segregation in General ....................................................................................... 5.3.1 Transverse Strips ................................................................................................................. 5.3.2 Strips in the Middle of the Pavement ............................................................................ 5.3.3 Strips in the Lateral Areas of the Pavement ................................................................. 5.3.4 Patches of Mix in the Surface Texture . .......................................................................... 5.4 Imprints . ............................................................................................................... 5.5 Longitudinal Step ................................................................................................ 5.6 Non-Uniform Surface Structure due to Crushed Grains ..................................
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147 148 158 158 159 160 161 162 164 166 167 168 169 170 170 171
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5. Imperfect Paving
VÖGELE Booklet on Paving
5.1
Systematic Elimination of Paving Errors
Three Major Factors for Paving
Machine Technology
Material
Job Site Logistics
In Germany and other countries, contractors must warrant that the roads they have built will function as required for a contractually specified period of time. The aim of cost-efficient paving is therefore to achieve a long service life for the road. This is primarily assured by a reliable and consistent paving process in which quality is not a matter of chance.
Machine Technology:
Which pave width? Which layer thickness? Which pavers and how many? Which screed type? Which screed version (extending screed or fixed-width screed, type of compaction, etc.)? Which pave speed? Which tamper speed? Which pressure for the pressure bars? Which type of sensors for grade and slope control?
Paving Material and Preparation:
Quality of the roadbase? Which material is to be used? Which grain size? (Note the ratio of layer thickness to maximum grain size) How much material is required/can be delivered per day or per hour?
Job Site Logistics:
How many mixing plants are to supply the mix? How many feed lorries will be needed? How experienced is the paving team? Which rollers will be needed and how many?
To optimize placement of the mix, all fundamental issues relating to the three major factors for paving must be clarified to the best possible extent before the project starts.
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5.1
Systematic Elimination of Paving Errors
Possibilities for Detecting Paving Errors on the Basis of Descriptions Formation of Undulations
Impressions in the Asphalt Pavement, Starting Humps, Insufficient Compaction
Open Surface
13. Has the ratio of maximum grain size to layer thickness been taken into account or has aggregate been shattered? (Since this effect is enhanced by the Screed Assist function, it should not be used when paving wearing course.) 14. Is the Screed Float valve working correctly? 15. Can the side plate move freely? 16. Have the braces (horizontal/vertical) been fitted correctly when paving large widths? B) Formation of undulations at regular intervals over the full width while paving
Segregation
Others
Formation of Undulations
A) Formation of undulations at irregular intervals over the full width while paving
1. Do the undulations also occur without automatic grade and slope control? If not, continue with step 5. 2. Check the sensitivity of NIVELTRONIC® and set up NIVELTRONIC® anew. 3. Inaccurate reference (wire wrongly tensioned, uneven base). 4. Check the choice of sensors (sonic sensors react to changes in temperature due to wind or rain). 5. Slack in the mechanism for height adjustment of the extending units or in the telescoping tubes? 6. Are the tractor unit/screed arm and fishplate tightly connected? 7. Slack in the torque restraint system? 8. Bolt-on extensions have a negative screed planing angle. 9. Tamper speed is too high for the set pave speed. 10. Check the setting of the pressure bars (height and pressure). 11. Pave speed is not constant. 12. Supply of mix is not constant. Have the sensors for the conveyors and augers been set correctly?
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1. Do the undulations also occur without automatic grade and slope control? If not, continue with step 5. 2. Check the sensitivity of NIVELTRONIC® and set up NIVELTRONIC® anew (replace components). 3. Inaccurate reference (uneven base or wire wrongly tensioned: distance between stakes = 6m). 4. Has the required precompaction been achieved behind the paver or are the undulations due to rolling errors? 5. Slack in the height adjustment mechanism of the extending units or in the telescoping tubes? 6. Slack in the torque restraint system? 7. Bolt-on extensions have a negative screed planing angle. 8. Tamper speed is too high or too low for the set pave speed (for approx. 3 m/min = 700 rpm, for approx. 5 m/min = 1,000 rpm, for approx. 10 m/min = 1,800 rpm). 9. Supply of mix is not constant. Have the sensors for the conveyors and augers been set correctly? 10. Have the braces (horizontal/vertical) been fitted correctly when paving large widths?
C) Undulations only form under the right or left extension units 1. Do the undulations also occur without automatic grade and slope control? If not, continue with step 5. 2. Check the sensitivity of NIVELTRONIC® and set up NIVELTRONIC® anew (replace components).
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5.1
3. Inaccurate reference on one side (uneven base or wire wrongly tensioned: distance between stakes = 6m). 4. Are the hydraulic ram for raise/lower screed, the Screed Float valve and the shutoff valves working properly? 5. Slack in the mechanism for height adjustment of the extending units or telescoping tubes? 6. Slack in the torque restraint system? 7. Supply of mix is not constant. Have the sensors for the conveyors and augers been set correctly? 8. The screed extensions or the telescoping system have been damaged by collisions with rollers or when reversing the paver. 9. Have the braces (horizontal/vertical) been fitted correctly when paving large widths? 10. Can the side plates move freely?
D) Undulations only form under the right or left bolt-on extensions
1. Has the permitted pave width been exceeded? 2. Have the bolt-on extensions been arranged correctly? (Correct order would be: long parts inside, short parts outside.) 3. Have the bolt-on extensions been secured correctly (correct bolts in the respective holes)? 4. Is the mounting flange flat? Have the set values been maintained (1mm angle of attack between one bolt-on extension and the next)? 5. Do some or all bolt-on extensions have a negative screed planing angle? 6. Do the undulations also occur without automatic grade and slope control? 7. Inaccurate reference on one side (wire wrongly tensioned, uneven base). 8. Are the hydraulic ram for raise/lower screed, the Screed Float valve and the shutoff valves working properly? 9. Slack in the mechanism for height adjustment of the extending units or in the telescoping tubes? 10. Slack in the torque restraint system? 11. Wrong attachment (have the wrong bolts been used or have some parts not been bolted completely)? 12. The tamper bars of the bolt-on extensions are considerably less worn than those of the basic screed.
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Systematic Elimination of Paving Errors
13. Supply of mix is not constant. Have the sensors for the conveyors and augers been set correctly? 14. Have the braces (horizontal/vertical) been fitted correctly when paving large widths?
Impressions in the Asphalt Pavement, Starting Humps, Insufficient Compaction
A) Screed produces marks in the pavement during paver stoppages, particularly along the rear edge
1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Screed Lock has not been activated or was activated too late. Faulty screed shutoff valves. Hydraulic rams for raise/lower screed: worn cylinder eyes. Screed is very heavy or material is incapable of supporting the weight of the screed. . Particularly heavy screeds are more likely to settle into the asphalt than light screeds. Excessively long paver stoppage. A very large screed planing angle has been set. Is the screed correctly braced (horizontally/vertically) when paving large widths? Lorries dock on too fast. Pressure bars start up too soon.
B) Screed produces uniform, deep marks in the pavement during paver stoppages
1. 2. 3. 4. 5. 6.
C) Uniform starting hump over the entire pave width
1. Screed Lock has not been activated or was activated too late. 2. Faulty screed shutoff valves. 3. Hydraulic rams for raise/lower screed: worn cylinder eyes.
Screed Lock has not been activated or was activated too late. Faulty screed shutoff valves. Hydraulic rams for raise/lower screed: worn cylinder eyes. Screed is very heavy or material is incapable of supporting the weight of the screed. Excessively long paver stoppage. Is the screed correctly braced (horizontally/vertically) when paving large widths?
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5.1
4. 5. 6. 7.
D) Starting hump under the extending units or bolt-on extensions
1. See C. 2. Check slack in the torque restraint system, hydraulic rams for extending/retracting the screed and the mechanism for height adjustment of the extending units. 3. Different degrees of wear on the tamper bars. 4. Different tamper speeds (basic screed, extending units, bolt-on extensions)? 5. Is there a uniform head of material in front of the screed (basic screed, extending units, bolt-on extensions)? 6. Has the side plate been set to the correct height? Is the side plate forcibly guided by spilled material etc.? 7. Is the screed correctly braced (horizontally/vertically) when paving large widths?
E) Insufficient compaction over the entire width
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Systematic Elimination of Paving Errors
Material has cooled excessively or paver has stopped for too long. Very high tamper speeds following a long paver stoppage. A very large screed planing angle has been set. Is the screed correctly braced (horizontally/vertically) when paving large widths?
1. Screed Assist has been activated or an excessively high pressure set (in combination with a low angle of attack!). 2. Tamper speed is too low. 3. Pave speed is too high. 4. Too few rollers or rollers are too light or of the wrong type. 5. Material is too cold. 6. Tamper stroke does not match the paving depth. 7. Worn tamper. 8. Screed planing angle is too steep. 9. Screed is too light or does not run smoothly. 10. Use of pressure bars would be more appropriate. 11. Unstable roadbase. 12. Aggregate grading is not homogeneous, thus making the material difficult to compact. 13. Have the pressure bars been vented?
F) Insufficient compaction under the extending units or bolt-on extensions
1. See E. 2. Incorrect compaction by rolling on one side. 3. If pressure bars are used: the pressure bars are not working properly in this area. 4. Tamper stroke or tamper has not been uniformly set over the full width. 5. Slack in the screed‘s telescoping guide system. 6. Check the position of the side plates if problems arise in the outer areas of the asphalt pavement during compaction. 7. Is the screed correctly braced (horizontally/vertically) when paving large widths?
Open Surface
A) Formation of stripes when starting work in the morning
1. Can tamper and pressure bars function correctly (not fouled or jammed)? 2. Screed has not yet heated up properly (heat for 30 minutes, then continue heating in the paving material). 3. Screed plates worn? 4. Material is too cold or has not been mixed homogeneously. 5. Pressure bars are set too low (correct position: 4mm above bottom edge of screed plate).
B) Scraped material under the extending units
1. The screed has not been extended fully and the extending units (which are lower than the screed) have scraped up the precompacted surface (height must be adjusted). 2. The screed has not been heated up correctly in this area (e.g. faulty heating rod).
C) Longitudinal stripes form while paving
1. Seal plates have not been fitted correctly between the basic screed and the extending units. 2. Distinct longitudinal stripe in the middle of the pavement (set a small crown if necessary). 3. Adjust height of centre auger box (to prevent a shortage in the supply of material). 4. Check the auger blades (to ensure that material is spread continuously).
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5.1
Systematic Elimination of Paving Errors
D) Permanently or temporarily open surface
D) Segregation at right angles to the direction of paver travel
1. Check the homogeneous nature of the mix (the material delivered by the mixing plants can vary enormously). 2. Material can sometimes segregate, stick together or cool during transport. 3. Insufficient heating power. 4. Material is too cold or there are major differences in grain size and no binder. 5. Wrong rollers are being used.
1. Material remains in the hopper for too long. 2. Ensure that the material hopper is always filled. 3. Check that the mixing plants deliver homogeneous mixes.
Segregation
A) Lengthwise segregation under the auger bearings
1. Increase distance between centre auger box and tamper shield. 2. Mount small auger blades on the left and right of the centre auger box to transport material under the bearing box. Generally fit auger blades with a smaller diameter. If necessary, they should be mounted so that the auger blades alternately transport the material inwards and outwards. 3. Change the height of the auger (normal: 4cm above the bottom edge of the screed).
B) Segregation in the outer areas of the asphalt pavement
1. Limiting plates for the auger tunnel are either missing or too short. 2. Auger sensors in wrong position (correct fitting at extreme ends of auger tunnel). 3. Ensure a constant head of mix in front of the screed.
C) Segregation at isolated points
1. Check correct operation of the screed heating (if heating power is too low, fine-grain material will accumulate and form slabs or lumps). 2. Gap between tamper shield and tamper is too large. Material can accumulate here and stick together. 3. Material is not homogeneously mixed on delivery. 4. Ensure that the screed is cleaned more thoroughly before and after use.
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Others
A) Required layer thickness is not maintained
1. Either the material constantly does not have sufficient load bearing capacity or its consistency is not homogeneous. 2. The screed is too heavy for the material (use Screed Assist or a fixed-width screed).
B) Thin layers cannot be paved
1. The screed is too light. 2. The screed floats at a very low level and responds too slowly or not at all to changes in parameters. 3. Tamper stroke is too large. 4. Ratio of maximum grain size to layer thickness is not maintained (aggregate is shattered).
C) Uneven surface in transverse direction
1. When working with the slope sensor, either the maximum permitted pave width is exceeded or the slope sensor vibrates excessively. 2. Either the material does not have sufficient load bearing capacity or its consistency is not homogeneous. 3. The screed is too heavy for the material (use Screed Assist or a fixed-width screed).
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VÖGELE Booklet on Paving
5.2
Paving Problems / Paving Errors
5.2
Paving Problems / Paving Errors
5.2.1
Irregularities when Passing over Mix
5.2.2
Pavement Irregularities due to Large Screed Planing Angle
Fault / Cause
Fault / Cause
Unless compensated by movement of the tow point rams, mix which has spilled into the area of the wheels or crawler tracks will lead to a change in the screed planing angle when passed over and cause irregularities to appear in the pavement.
When paving mix of poor bearing capacity (e.g. base course), the screed adopts a too large planing angle while paving to reach the specified layer thickness.
Remedy
Remedy
Avoid spilling mix in the area of the wheels or crawler tracks and remove any mix which has spilled. For tracked pavers, fit baffle plates in front of crawler tracks.
A too large screed planing angle promotes irregularities in the pavement.
Screed Assist Pressure
Use the Screed Assist function. Set a low, constant pressure. Increase tamper speed and reduce the pave speed. Increase the tamper stroke length.
Recommendation
Screed Float
158
The Screed Assist function must not be used when paving wearing course.
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VÖGELE Booklet on Paving
5.2
Paving Problems / Paving Errors
5.2
Paving Problems / Paving Errors
5.2.3
Hump Formed when Resuming Paving
5.2.4
Short Irregularities in Transverse Direction
Fault
a = Screed Plate b = Base
A hump appears in the pavement when resuming paving after a stop.
Fault Small irregularities appear at short intervals.
a
Stop
b Negative Screed Planing Angle
a = Screed Plate b = Base
Weight of Screed
Cause
Forward Motion at
flo
Up
Every stop disturbs the floating screed‘s equilibrium of forces. The primary factors influencing the screed‘s floating behaviour are the screed weight, the forward motion and the upfloat tendency. The hump also depends on the hardness of the bitumen, the extent to which the mix has cooled, the type of screed and shape of tamper shield and tamper bar. The bearing capacity of the mix increases with decreasing mix temperature, thus promoting the hump as the screed tow points remain unchanged.
a b Positive Screed Planing Angle
Basic Screed
Remedy Screed Freeze Pressure
160
Activate the Screed Freeze function. Paver stops should generally be kept as short as possible. If necessary, continue paving with mix from the material hopper and then stop again in order to spread the break in paving over several stops.
0.5mm (maximum)
Extending Unit
Cause Here the screed planing angle is negative. As a result, only the tamper bar and the front part of the screed plate are actually in contact with the mix. The small contact area is not sufficient to level out the irregularities in the surface.
Remedy The screed planing angle is normally positive. This is the only way to ensure that the entire screed plate is used to level out minor irregularities in the pavement. A constant, level surface is produced. The screed plates of an extending screed must all be set to the same planing angle so that the screed‘s floating behaviour is not impaired by different pave widths. The leading edge of the screed plate on the extending units should be at least 0.5mm higher than the trailing edge when setting up the screed.
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VÖGELE Booklet on Paving
5.2
Paving Problems / Paving Errors
5.2.5
Periodic Irregularities in Longitudinal Direction
Fault Pavement irregularities at almost constant intervals. The irregularities are more pronounced in the area of the extending units than behind the basic screed.
Wear in the torque restraint system.
Torque Restraint System Sliding Blocks
Cause Irregularities in the reference from which the grade sensor picks up the actual elevation (e.g. sagging tensioned wire). The distance between stakes should be no more than 6m.
Worn teflon tapes in telescoping tubes. Telescoping Tube
Slack in the extending units‘ mechanisms for height adjustment.
Mechanism for Height Adjustment
Loose bolts on the screed arm.
Teflon Tape
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VÖGELE Booklet on Paving
5.3
Segregation in General
If segregation occurs in front of the screed, it may be possible to improve the situation by adjusting the auger height. If this proves unsuccessful, smaller or different auger blades can, in addition, be fitted to the auger shaft.
Fault Segregation in the surface behind the screed.
Small Layer Thickness
Cause Segregation can easily occur when paving mixes containing different grain sizes and little binder. Larger grains in the mix tend to collect outside, in front of the pile. Such segregation may arise as the mix is loaded into the truck, when transferred to the paver or when conveyed through the paver.
Remedy If the segregation occurs in the paver‘s material hopper, the conveyor should be covered with mix when the hopper sides are folded in. In addition, the hopper sides should be operated as little as possible in order not to move coarse grains from the sides inwards onto the conveyor and to the rear of the machine. The hopper sides should only be folded in if the material at the sides is cooling off so rapidly that it can no longer be laid.
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Large Layer Thickness
TIP The auger blades should be set 4cm (approx.) above the screed’s trailing edge.
If the auger blades are smaller or different, the auger must rotate more quickly or more continuously so that the material is mixed more effectively in the auger tunnel. Limiting plates for the auger tunnel and strike-off plates must be fitted regardless of the size of auger blades.
If segregation occurs in the area of the centre auger box, the screed can be moved further to the rear in order to increase the head of mix in front of the screed and ensure that all grain sizes are actually conveyed behind the centre auger box.
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5.3
Segregation in General
5.3
Segregation in General
5.3.1
Transverse Strips
5.3.2
Strips in the Middle of the Pavement
Fault
Fault
Strips of segregated material appear in the pavement at right angles to the direction of travel after every change of feed lorry.
A porous / rough strip of segregated material appears in the middle of the pavement.
Cause
Cause
Segregation is always promoted by a poor condition of the mix (not enough bitumen, not sufficiently homogeneous). It is also promoted by operation of the hopper sides when the hopper is almost empty, with the result that segregated material is moved to the auger tunnel.
Segregation is promoted, particularly in the middle of the pavement, if the head of mix in front of the screed is too low.
Remedy Operate the hopper sides less often and not at all when the hopper is almost empty. Ensure that the material hopper is always well filled.
Change Position of Fishplate
Larger Distance
Spreading Direction
Remedy Increase distance between centre auger box and tamper shield. Set auger to a higher position. Turn one or two auger blades in the area of the centre auger box round to convey mix inwards or fit smaller auger blades instead.
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VÖGELE Booklet on Paving
5.3
Segregation in General
5.3
Segregation in General
5.3.3
Strips in the Lateral Areas of the Pavement
5.3.4
Patches of Mix in the Surface Texture
Fault
Fault
Strips of segregated mix appear in the lateral areas of the pavement with increasing pave width.
Changes in the surface texture appear sporadically while paving. The surface is smoother or smeared with bitumen.
Cause
Cause
Segregation is promoted by the absence of limiting plates for the auger tunnel and if the sensors for the mix level in the auger tunnel have not been set correctly.
The fault is due to mainly fine grains with a high bitumen content, such as residues from the mixing plant which are detached uncontrolledly and delivered to the site with the mix.
Remedy
Such accumulation of mix may also occur if the screed has not been heated sufficiently. In such a case, fines accumulate at the tamper shield or at the tamper bar and are then detached uncontrolledly from time to time, changing the surface texture.
Fit limiting plates across the maximum pave width, if necessary. Install mix level sensors at the sides and see to optimal setting. Ensure a good, constant level of mix in the auger tunnel.
Remedy Check correct operation of the screed heating system. Paver and screed must be cleaned thoroughly while paving and, above all, when paving is finished. If necessary, demount, clean and re-adjust the tamper shield. Inform the mixing plant operator of the segregation. Reduce tamper speed.
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VÖGELE Booklet on Paving
5.4
Imprints
5.5 Longitudinal Step
5.6
Non-Uniform Surface Structure due to Crushed Grains
Fault
Step
Fault
Cause
The trailing edge of the screed leaves an imprint at right angles to the pave width.
The compacting impact of the screed is too high for the layer thickness, thus crushing the grains.
Cause The screed sinks into the mix during a paver stop. This may be due to an interruption in the floating of the screed, so that the screed is pressed onto the material under the force of its own weight. The imprint, however, may also be due to rough docking by the feed lorry at the front, with a shock propagating to the screed at the rear of the paver.
Remedy Ensure that the rams for raising / lowering the screed hold the screed during the paver stop (valves on the rod side must close). Ensure a level base to prevent the paver pitching. Work with a small screed planing angle.
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When paving a layer of varying thickness, grains are crushed in the thin area. This is revealed by the colour of stone or whitish powder appearing on the surface although all grains in the mix were originally coated with bitumen.
Fault
The largest grains are too large for the layer thickness paved.
A step appears behind the screed between its basic unit and its extending units.
Cause The screed normally operates with a positive planing angle. Since the extending units are offset to the rear, any change in the planing angle will also affect the elevation of the screed’s basic unit and its extending units.
Remedy Set the compacting systems in accordance with the thinnest layer thickness. Pave a level regulating layer if necessary.
Remedy Adjust the height of the extending units until a level pavement surface is obtained behind the screed.
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VÖGELE Booklet on Paving
6
Paving Materials in Detail
6.1 General Pavement Structure .............................................................................. 6.2 Producing Asphalt Mix ........................................................................................ 6.3 Types of Pavement Layers . ................................................................................. 6.4 Bitumen Grades Used .......................................................................................... 6.5 Asphalt Types and their Composition ............................................................... 6.5.1 Stone Mastic Asphalt ......................................................................................................... 6.5.2 Asphaltic Concrete (Paved Hot) ...................................................................................... 6.5.3 Asphaltic Binder . ................................................................................................................ 6.5.4 Asphalt for Base Course .................................................................................................... 6.5.5 Porous Asphalt .................................................................................................................... 6.6 Mix Temperatures in °C . ...................................................................................... 6.7 Causes of Poor Quality Asphaltic Concrete Mixes for Hot Paving .................. 6.8 Emulsion Types . ...................................................................................................
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173 174 180 184 185 186 186 188 190 192 194 196 197 198
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6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.1
General Pavement Structure4
Asphalt Base Course Street Furniture with Expansion Joints Manhole
Gate Valve Transverse Joint (End of Day)
Surface
Expansion Joint
Verge
b
Asphalt Binder Course
a c
Asphalt Base, Binder and Wearing Courses Earth, Roadbase Existing Layers (if any)
Expansion Joint Longitudinal Joint
Functions fulfilled by the asphalt base course: The purpose of the base course is to ensure quick and effective protection of the roadbase against water in order to maintain its load bearing capacity. Base courses provide a uniform and stable foundation for the layers placed on top (asphalt binder and wearing courses). Firmly bonded with the asphalt binder and wearing courses, the base course must absorb the forces from traffic during the road‘s service life and ensure that these forces are uniformly distributed into the roadbase.
Adjacent Areas a = Drain b = Kerb c = Gutter
For technical and economic reasons, asphalt pavements are made up of different layers: asphalt base course, binder course and wearing course. Each layer has a specific function and contributes to the pavement’s load bearing capacity, depending on its thickness and position in the overall structure. The pavement layers, bonded in a compact structure, are crucial for the pavement’s durability and long service life.
For more heavily trafficked roadways, an asphalt binder course is placed between the asphalt base course and the asphalt wearing course. Functions fulfilled by the asphalt binder course: The binder course reduces any remaining unevenness in the asphalt base courses so that the asphalt wearing course can be paved with uniform thickness and the required evenness. Above all, however, the binder course must absorb the shear forces from traffic which are particularly high in this part of the pavement, and prevent deformation of the roadway.
4 Diagram on page 174 in accordance with the asphalt LEITFADEN: Qualität von Anfang an (Asphalt Manual, Quality from the Outset), published by DAV Deutscher Asphaltverband e.V. (German Asphalt Association), edition August 2007, page 5. // Text and diagrams on pages 174 - 177 in accordance with the asphalt LEITFADEN: Ausschreiben von Asphaltarbeiten (Asphalt Manual, Inviting Tenders for Asphalt Paving Works), published by DAV Deutscher Asphaltverband e.V. (German Asphalt Association), edition December 2003, pages 12 - 15.
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VÖGELE Booklet on Paving
6.1
General Pavement Structure
Combined Asphalt Base and Wearing Course As the name indicates, a combined asphalt base and wearing course is a combination of base course and wearing course. These courses were specially designed for the rather thin pavements used for rural roads. Combined base and wearing course is paved when the overall thickness, though sufficient to ensure the specified load bearing capacity, is not great enough (e.g. 8 to 10cm) to be split into asphalt base course and asphalt wearing course without falling below the minimum pavement thickness required for constructional reasons.
Abbreviations for ashalt mixes and asphalt grades5 Marking of asphalt mix according to DIN EN 13108
Examples: AC 32 T
AC = Asphaltic Concrete
Asphaltic concrete for asphalt base courses with a maximum screen size of 32mm for use in traffic areas with heavy loads.
SMA = Stone Mastic Asphalt MA = Mastic Asphalt
Tasks Fulfilled by the Individual Layers
PA
= Porous Asphalt
Shear Stress from Traffic
AC 11 DN Wearing Course
Resistance to Wear, Waterproofness
Binder Course
Shear Strength
Base Course
National supplements for classifying asphaltic concrete
Asphaltic concrete for asphalt wearing courses with a maximum screen size of 11mm for use in traffic areas with normal loads.
T
= Asphalt for base course
MA 8 S
B
= Asphaltic binder
D
= Asphalt for wearing course
Mastic asphalt with a maximum screen size of 8mm for use in traffic areas with heavy loads.
TD = Asphalt for combined base and wearing course Load Bearing Capacity
National supplements for load level L
= Light loads
N
= Normal loads
S
= Heavy loads
5 From DEUTAG GmbH & Co.KG: Asphaltsortentafel (Table of types of asphalt mix)
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VÖGELE Booklet on Paving
6.1
General Pavement Structure
Asphalt Base / Wearing Course
Asphalt Base / Wearing Course
Type of Asphalt Mix Construction Class
Type of Asphalt Mix Construction Class
Layer Thickness (cm)
AC 32 T S*
SV / I / II
8 (min.)
AC 22 T S*
SV / I / II / II
8 (min.)
AC 16 T S
5 (min.)
AC 32 T N*
8 (min.)
IV / V / VI
Layer Thickness (cm)
VI
5 - 10
AC 32 T L
8 (min.)
MA 11 S*
SV / I / II / III
3.5 - 4
8 (min.)
MA 8 S*
SV / I / II / III
2.5 - 3.5
5 (min.)
MA 5 S*
SV / I / II / III
2-3
Layer of Asphaltic Binder Type of Asphalt Mix Construction Class
Layer Thickness (cm)
AC 22 B S*
SV / I / II
7 - 10
AC 16 B S*
SV / I / II /III
5-6
AC 16 B N*
IV
AC 11 B N
5-6 Level regulating course
Layer of Asphaltic Concrete Type of Asphalt Mix Construction Class
AC 16 D S
5-6
AC 11 D S*
4-5
II / III
AC 8 D S
3-4
AC 11 D N*
IV / V
3-4
AC 8 D N*
IV / V
3-4
AC 11 D L
IV / V / VI
3.5 - 4
MA 8 N*
IV / V / VI
2.5 - 3.5
MA 5 N*
IV / V / VI
2-3
SMA 11 S*
SV / I / II / III
SMA 8 S*
SV / I / II / III
2 - 3.5
VI
2-3
Layer of Porous Asphalt Layer Thickness (cm)
PA 16
SV / I / II / III
>5
SV / I / II / III
5-6
SV / I / II / III
4.5 - 5
AC 8 D L*
VI / Cycle paths
3-4
and footpaths
3-4
PA 8*
Thickness for Asphalt Works (cm)
AC 8 D N, AC 8 D L
2 - 3
2
3 - 4
3
3,5 - 4,5
4
AC 11 D S
4 - 5
4
AC 16 D S
5 - 6
5
SMA 5 N
2 - 3
2
SMA 8 N
2 - 3,5
3
SMA 8 S
3 - 4
3,5
SMA 11 S
3,5 - 4
4
MA 5 S, MA 5 N
2 - 3
2
2,5 - 3,5
3
MA 11 S, MA 11 N
3,5 - 4
3,5
AC 22 B S
7 - 10
≥8
AC 16 B S
5 - 9
≥6
AC 16 B N
5 - 6
≥5
Asphalt Base Course
AC 22 T S, AC 22 T N, AC 22 T L
≥ 8
≥8
AC 32 T S, AC 32 T N, AC 32 T L
≥ 8
≥8
Combined Asphalt Base / Wearing Course
AC 16 TD
≥ 8
≥8
3-4
IV / V / VI
AC 5 D L*
(cm)
2-3
SMA 5 N*
PA 11*
Recommended Layer
MA 8 S, MA 8 N
3.5 - 4
SMA 8 N*
Type of Asphalt Mix Construction Class
AC 5 D L AC 11 D N, AC 11 D L
Layer Thickness (cm)
3.5 - 4.5
* From DEUTAG GmbH & Co.KG: Asphaltsortentafel (Table of types of asphalt mix)
Asphalt Wearing Course
Layer of Stone Mastic Asphalt
SMA 5 S Layer Thickness (cm)
Layer Thickness (cm)
MA 11 N*
Type of Asphalt Mix Construction Class
Layer Thickness
Type of Asphalt Mix Construction Class
Footpaths
Layer
Layer of Mastic Asphalt
5 (min.)
AC 16 T L
Types of Asphalt
AC 16 T N AC 22 T L*
178
AC 16 T D*
Asphalt mixes with their prescribed ranges for layer thickness and the recommended layer thickness for asphalt works.6
Asphalt Binder Course
6 From DEUTAG GmbH & Co.KG: Asphaltsortentafel (Table of types of asphalt mix)
179
6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.2
Producing Asphalt Mix7
Principle of Operation
Technical Equipment of an Asphalt Mixing Plant
Asphalt has been produced according to roughly the same principle for many years. Regardless of the mixing plant make, certain system components are always assembled in a similar order.
Screening Unit
Hot Elevators
5
Storage Bin for Filler
9 18
6
Batching Hoppers
Storage Bin for Mix Hot Silage
7 8
2
12 10 16
Aggregate Scales Binder Batching Unit Filler Scales
The usually damp mineral aggregate (1) (sand, coarse and fine chippings), stocked on site, is fed into batching hoppers (2) from which the grain sizes needed for an asphalt mix are withdrawn in roughly the right ratios and delivered via a conveyor (3) to the rotary drier (4). In the rotary drier, the aggregate is dried and heated to the temperature required for asphalt production. To save space, the subsequent parts are frequently arranged one above the other in a tower-like construction. Hot elevators (5) are used to transport the heated aggregate to the uppermost level of the tower.
17
4
3 11
Skip
Not shown:
Mixer
1 Storage Hoppers for Aggregate 13 Storage Hoppers for Additives 14 Additive Batching
Conveyor
15 Batching Unit for Granulated Asphalt 19 Vehicle Weighbridge
180
Bitumen Storage Tank Rotary Drier 7 Text and diagrams on pages 180 - 183 in accordance with the asphalt LEITFADEN: Qualität organisieren, wer, wann, was, wie, wo (Asphalt Manual, Organizing Quality: Who, What, When, Where and How), published by DAV Deutscher Asphaltverband e.V. (German Asphalt Association), edition June 1999, pages 32 - 33.
181
6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.2
Producing Asphalt Mix
View Inside the Mixing Tower
5
Screening Unit
6
Hot Silage
7
Aggregate Scales
8 10
12
16
Hot Elevator
Filler Scales
Mixer Binder Batching Unit
182
The aggregate first proceeds via the elevator to a screening unit (6) where the previously batched mix is broken down into individual grain sizes again.
pre-treatment, e.g. addition via mixer, hot elevator or “parallel“ drier. In the “parallel“ drier, the granulated asphalt is gently dried and heated separately.
The screening unit cannot be used if the aggregate in the hot elevator contains reclaimed asphalt material. The storage bins for the individual grain sizes under the screening unit are referred to as hot silage (7). From here, the grain sizes can be batched according to weight by means of the aggregate scales (8). When all the required coarse aggregate has been filled into the weighing hopper, the complete batch is transferred to the mixer (16).
All ingredients are homogeneously mixed in the mixer. The finished asphalt is then transported to the storage bin for mix (18) in a mobile skip (17). The mix is finally loaded into trucks from the storage bin and transported to the job site after being weighed (19).
Filler, binder and any additives required enter the mixer by other routes. Filler is stored in the storage bin (9), binder in storage tanks (11). Special batching devices are used for these materials, namely the filler scales (10) and the binder batching unit (12). Additives are stored as required by their nature (13) and delivered to the mixer by hand or via automatic batching units (14). Reclaimed asphalt material is granulated before being added to the process via a separate batching unit (15). Different processes are distinguished according to the point of addition or type of
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6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.3
Types of Pavement Layers
Type of Layer
Method of Construction
Asphalt Layers
Asphaltic concrete (paved hot) Stone mastic asphalt Mastic asphalt Asphalt seal Mix for combined base course / wearing course Asphaltic concrete
Asphalt Layers (Others)
Thin layers (paved cold) Thin layers (paved hot) Porous asphalt etc.
Concrete Layers
Concrete surfacing Concrete surfacing, reinforced Prestressed concrete surfacing Roller compacted concrete Concrete tracks etc.
Paving Stones
Layers without Binder
184
6.4
Natural paving stones Large, medium, small paving stones Mosaic pavement Concrete paving stones Square, rectangular, hexagonal paving stones Jointing compounds Slabs Concrete etc.
Water-bound gravel or crushed stone layers
Bitumen Grades Used
Bitumen for Roads According to DIN 1995
Type of Mix
Polymer Modified Bitumen According to TL PmB (Part 1)
160/200 70/100 50/70 30/45 20/30
Asphaltic Base Course
m
l
l
m
PmB 80A
PmB 65A
PmB 45A
PmB 25A
m
Asphaltic Binder
l
l
l
Asphaltic Concrete
m
l
l
m
Stone Mastic Asphalt
m
l
l
m
Porous Asphalt
l
l
Mastic Asphalt
Combined Base and Wearing Course
l
l
Joint Sealing Compound
l
Hydraulic Engineering
m
m
m
l
l
l
m
l
m
l
l
l
l
l
l
m
l
l
l Used as standard m Used in special cases
185
6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.5
Asphalt Types and their Composition8
6.5.1
Stone Mastic Asphalt
Stone Mastic Asphalt is a mix containing a high proportion of chippings and bitumen. Since the mix contains a large portion of chippings and coarse chippings, as well as a relatively small amount of sand, stabilizing binders (e.g. organic and mineral fibres, silicic acid or polymers) need to be added to the bitumen when used for road construction, so that the chippings can absorb the shear forces due to traffic. Aggregate used: Stone dust Crushed sand Double broken and double screened chippings
Use of Stone Mastic Asphalt: When used for wearing course, Stone Mastic Asphalt is characterized by particularly high stability and resistance to wear making it ideal for use on urban roads and highways with high traffic loads. The grain composition makes it highly suitable for paving in varying layer thicknesses or on an uneven base without any significant loss of quality. Final compaction should be performed immediately after laying using heavy static rollers. So that the necessary non-skid property is assured as soon as the road is opened to traffic, 1 - 2kg/m² of dedusted double broken and double screened chippings (2/5mm) or 0.5 - 1kg/m² of mixed crushed sand and chippings need to be evenly spread on the hot asphalt surface and rolled in. Loose chippings must be removed after cooling.
The maximum grain size can be 5, 8 or 11mm. Requirements to be Met by Stone Mastic Asphalt (SMA) Designation
Unit
SMA 11 S
SMA 8 S
SMA 5 S
SMA 8 N
SMA 5 N
Materials Mineral aggregate (on delivery) Share of crushed grain Resistance to shattering Resistance to polishing % Minimum share of fine grains with ECS 35 Binder, type and grade
C100/0; C 95/1; C 90/1 SZ18 / LA20 PSV indicated (51) 100 25/55 - 55; 50/70
C100/0; C 95/1; C 90/1 SZ18 / LA20 PSV indicated (51) 100 25/55 - 55; 50/70
C100/0; C 95/1; C 90/1 SZ18 / LA20 PSV indicated (48) 100 45/80 - 50; 50/70;
C 90/1 SZ18 / LA20 PSV indicated (48) 50 50/70; 70/100;
C 90/1 SZ18 / LA20 PSV indicated (48) 50
Composition of the Asphalt Mix Mineral aggregate Sieve size 16mm % by mass 11.2mm % by mass 8mm % by mass 5.6mm % by mass 2mm % by mass 0.063mm % by mass Minimum binder content Carrier for binder % by mass
100 90 to 100 50 to 65 35 to 45 20 to 30 8 to 12 Bmin 6.6 0.3 to 1.5
Asphalt Mix Minimum voids content MPK Maximum voids content MPK Degree to which voids are filled % Proportional depth of ruts %
Vmin 2.5 Vmax 3.0 to be indicated to be indicated
100 90 to 100 100 35 to 55 90 to 100 20 to 30 30 to 40 8 to 12 7 to 12 Bmin 7.2 Bmin 7,4 0.3 to 1.5 0.3 to 1.5
100 90 to 100 35 to 60 20 to 30 7 to 12 Bmin 7.2 0.3 to 1.5
100 90 to 100 30 to 40 7 to 12 Bmin 7.4 0.3 to 1.5
Vmin 2.5 Vmin 2.0 Vmin 1.5 Vmin 1.5 Vmax 3.0 Vmax 3.0 Vmax 3.0 Vmax 3.0 to be indicated to be indicated to be indicated to be indicated to be indicated
8 Tables page 186 - 195 from source: TL Asphalt-StB 07.
186
187
6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.5
Asphalt Types and their Composition
6.5.2
Asphaltic Concrete (Paved Hot)
Hot-paved asphaltic concrete is a well-graded aggregate mix with low voids content which displays high density, stability and shear resistance after laying and final compaction by rolling. The relatively large proportion of chippings contained in the asphaltic concrete produces a wearing course with excellent non-skid property and stability due to the good interlocking of grains.
Use of Asphaltic Concrete: Primarily laid on binder course. Meets the requirements of wearing course on urban and country roads.
Aggregate used: Stone dust Natural sand and crushed sand Double broken and double screened chippings The maximum grain size can be 5, 8, 11 or 16mm, but must comply with the layer thickness. Requirements to be Met by Asphaltic Concrete for Asphalt Wearing Courses Designation
Unit
Materials Mineral aggregate (on delivery) Share of crushed grain Resistance to shattering Resistance to polishing % Minimum share of fine grains with ECS 35 Binder, type and grade
AC 16 D S
AC 11 D S
C 90/1 C 90/1 SZ18 / LA20 SZ18 / LA20 PSV indicated (48) PSV indicated (48) 50 50 25/55-55; 50/70 25/55-55; 10/40-65 50/70
AC 8 D S
AC 11 D N
AC 8 D N
AC 11 D L
AC 8 D L
AC 5 D L
C 90/1 SZ18 / LA20 PSV indicated (48) 50 25/55-55; 50/70
C 90/1 SZ22 / LA25 PSV indicated (42)
C 90/1 SZ22 / LA25 PSV indicated (42)
C 90/1 SZ26 / LA30 PSV indicated (42)
C 90/1 SZ26 / LA30 PSV indicated (42)
C 90/1 SZ26 / LA30 PSV indicated (42)
50/70; 70/100
50/70; 70/100
70/100; 50/70
70/100
70/100
100 90 to 100 70 to 90 45 to 65 8 to 20 6 to 12 Bmin 6.6
100 90 to 100 50 to 70 9 to 24 6 to 14 Bmin 7.0
Composition of the Asphalt Mix Mineral aggregate Sieve size 22.4mm % by mass 100 16mm % by mass 90 to 100 100 100 100 11.2mm % by mass 70 to 85 90 to 100 100 90 to 100 100 90 to 100 8mm % by mass 70 to 85 90 to 100 70 to 85 90 to 100 70 to 90 5.6mm % by mass 65 to 85 70 to 85 2mm % by mass 35 to 45 40 to 50 40 to 55 45 is 55 45 to 60 45 to 60 0.125mm % by mass 7 to 17 7 to 17 8 to 20 8 to 22 8 to 20 8 to 22 0.063mm % by mass 5 to 9 5 to 9 6 to 12 6 to 12 6 to 12 6 is 12 Bmin 6.0 Bmin 6.2 Bmin 6.2 Bmin 6.4 Bmin 6.4 Minimum binder content Bmin 5.4 Asphalt Mix Minimum voids content MPK Maximum voids content MPK Degree to which voids are filled %
188
Vmin 2.5 Vmin 2.5 Vmax 4.5 Vmax 4.5 to be indicated to be indicated
Vmin 2.0 Vmin 1.5 Vmin 1.5 Vmin 1.0 Vmin 1.0 Vmin 1.0 Vmax 3.5 Vmax 3.5 Vmax 3.5 Vmax 2.5 Vmax 2.5 Vmax 2.5 to be indicated to be indicated to be indicated to be indicated to be indicated to be indicated
189
6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.5
Asphalt Types and their Composition
6.5.3
Asphaltic Binder
Asphaltic binder is a mix of graded grain size to which binder has been added. The grain size composition is such that the dense structure and grain size distribution of the asphaltic binder cannot change when subjected to traffic loads.
Use of Asphaltic Binder Course: Used as base under asphalt wearing course to absorb the shear forces due to traffic. Used for level regulating course and to compensate irregularities in the base.
Aggregate used: Stone dust Natural sand and crushed sand Gravel and / or chippings The maximum grain size can be 11, 16 or 22mm.
Requirements to be Met by Asphaltic Binder Designation
Unit
Materials Mineral aggregate (on delivery) Share of crushed grain Resistance to shattering
AC 22 B S
AC 16 B S
AC 16 B N
AC 11 B N
C100/0; C 95/1; C 90/1 SZ18 / LA20
C100/0; C 95/1; C 90/1 SZ18 / LA20 SZ22 / LA25 PSV indicated (48) 100 25/55-55; 30/45 10/40-65
C 90/1 SZ18 / LA20
C 90/1 SZ18 / LA20
PSV indicated (48) 50 50/70; 30/45
PSV indicated (48) 50 50/70;
Resistance to polishing % Minimum share of fine grains with ECS 35 Binder, type and grade
PSV indicated (51) 100 25/55-55; 30/45 10/40-65
Composition of the Asphalt Mix Mineral aggregate Sieve size 31.5mm % by mass 100 22.4mm % by mass 90 to 100 100 100 16mm % by mass 65 to 80 90 to 100 90 to 100 11.2mm % by mass 65 to 80 60 to 80 8mm % by mass 2mm % by mass 25 to 33 25 to 30 25 to 40 0.125mm % by mass 5 to 10 5 to 10 5 to 15 0.063mm % by mass 3 to 7 3 to 7 3 to 8 Bmin 4.4 Bmin 4.4 Minimum binder content Bmin 4.2 Asphalt Mix Minimum voids content MPK Maximum voids content MPK Degree to which voids are filled % Proportional depth of ruts %
190
Vmin 3.5 Vmax 6.5 to be indicated to be indicated
100 90 to 100 60 to 80 30 to 50 5 to 18 3 to 8 Bmin 4.6
Vmin 3.5 Vmin 2.5 Vmin 2.5 Vmax 6.5 Vmax 5.5 Vmax 5.5 to be indicated to be indicated to be indicated to be indicated
191
6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.5
Asphalt Types and their Composition
6.5.4
Asphalt for Base Course Function of the Asphalt Base Course: When building roads, the asphalt base course must quickly and effectively seal the underlying layers against rainwater while at the same time providing a uniform, stable and even foundation for high-quality binder and wearing courses. The durably bound asphalt base course subsequently helps absorb the traffic load and distribute it over the base, together with the layers above it.
Asphalt base is a mixture of bitumen and aggregate. Aggregate used: Stone dust Natural sand and crushed sand Gravel and / or chippings The maximum grain size can be 16, 22 or 32mm. The basic idea underlying this mix, namely to use predominantly local aggregate, cannot always be realized under modern conditions. Asphalt base course can be paved at temperatures down to -3 °C due to the high heat-retaining capacity of thick asphalt layers.
Requirements to be Met by Asphaltic Concrete for Asphalt Base Course Mixes Designation
Unit
Materials Mineral aggregate (on delivery) Share of crushed grain Minimum share of fine % grains with ECS 35 Binder, type and grade
AC 32 T S
AC 22 T S
AC 16 T S
AC 32 T N
AC 22 T N
AC 16 T N
AC 32 T L
AC 22 T L
AC 16 T L
C 50/30
C 50/30
C 50/30
C NR
C NR
C NR
C NR
C NR
C NR
50 50/70; 30/45
50 50/70; 30/45
50 50/70; 30/45
70/100; 50/70
70/100; 50/70
70/100; 50/70
70/100
70/100
70/100
Composition of the Asphalt Mix Mineral aggregate Sieve size 45mm % by mass 100 100 100 31.5mm % by mass 90 to 100 100 90 to 100 100 90 to 100 100 22.4mm % by mass 75 to 90 90 to 100 100 75 to 90 90 to 100 100 80 to 90 90 to 100 16mm % by mass 75 to 90 90 to 100 75 to 90 90 to 100 80 to 90 11.2mm % by mass 75 to 90 75 to 90 2mm % by mass 25 to 40 25 to 40 25 to 40 25 to 40 25 to 40 25 to 40 40 to 60 40 to 60 0.125mm % by mass 4 to 14 4 to 14 4 to 14 4 to 14 4 to 14 4 to 14 4 to 17 4 to 17 0.063mm % by mass 2 to 9 2 to 9 2 to 9 3 to 9 3 to 9 3 to 9 3 to 10 3 to 10 Bmin 3.8 Bmin 4.0 Bmin 4.0 Bmin 4.0 Bmin 4.0 Bmin 4.0 Bmin 4.0 Minimum binder content Bmin 3.8 Asphalt Mix Minimum voids content MPK Maximum voids content MPK
192
Vmin 5.0 Vmax 10.0
Vmin 5.0 Vmax 10.0
Vmin 5.0 Vmax 10.0
Vmin 4.0 Vmax 10.0
Vmin 4.0 Vmax 10.0
Vmin 4.0 Vmax 10.0
Vmin 4.0 Vmax 10.0
Vmin 4.0 Vmax 10.0
100 90 to 100 80 to 90 40 to 60 4 to 17 3 to 10 Bmin 4,2 Vmin 4,0 Vmax 10,0
193
6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.5
Asphalt Types and their Composition
6.5.5
Porous Asphalt
Porous asphalt (PA) comprises coarse aggregate, fine aggregate if required, filler and polymer-modified bitumen as a binder, as well as additives as carriers for the binder. The aggregate mix contains a very large proportion of voids. Aggregate used: Coarse crushed aggregate with high resistance to polishing. The maximum grain size can be 8, 11 or 16mm.
Use of Porous Asphalt: Porous asphalt wearing courses are primarily used for noise abatement on two-lane roads outside town. The considerable permanent reduction in noise levels (DStrO value of -5 dB(A)) is essentially achieved through the extremely high voids content of the compacted layer (22% to 28% by volume) and through the favourable texture of the road surface. Most of the noise is directed downwards into the asphalt layer and largely absorbed in the interconnected voids. Surface water (rain) additionally percolates into the layer, where it is discharged on the dense or sealed base – and not on the surface, as with other types of asphalt wearing course. This reduces the incidence of spume and the risk of aquaplaning. Depending on the maximum speed permitted and on the proportion of heavy goods traffic, asphalt wearing courses can be made from one (OPA) or two (ZWOPA) layers of porous asphalt.
Requirements to be Met by Porous Asphalt (PA) Designation
Unit
PA 16
PA 11
PA 8
Materials Mineral aggregate (on delivery) C100/0 C100/0 Share of crushed grain C100/0 Resistance to shattering SZ18 / LA20 SZ18 / LA20 SZ18 / LA20 Resistance to polishing PSV NR PSV indicated (54) PSV indicated (54) % 100 100 100 Minimum share of fine grains with ECS 35 Binder, type and grade 40/100-65 40/100-65 40/100-65 Composition of the Asphalt Mix Mineral aggregate Sieve size 22.4mm % by mass 100 16mm % by mass 90 to 100 100 11.2mm % by mass 5 to 15 90 to 100 100 8mm % by mass 5 to 15 90 to 100 5.6mm % by mass 5 to 15 2mm % by mass 5 to 10 5 to 10 5 to 10 0.063mm % by mass 3 to 5 3 to 5 3 to 5 Bmin 6.0 Bmin 6.5 Minimum binder content Bmin 5.5 Carrier for binder % by mass ≥ 0.3 ≥ 0.4 ≥ 0.5 Asphalt Mix Vmin 24 Vmin 24 Minimum voids content MPK Vmin 24 Vmax 28 Vmax 28 Vmax 28 Maximum voids content MPK Degree to which voids are filled % to be indicated to be indicated to be indicated Proportional depth of ruts % to be indicated to be indicated
194
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VÖGELE Booklet on Paving
6.6
Mix Temperatures in °C
6.7 Causes of Poor Quality of Asphaltic Concrete Mixes for Hot Paving Observed Defects
Type of Asphalt Type of Binder
Aphaltic Binder
Asphaltic Concrete (Paved Hot)
Stone Mastic Asphalt
Mastic Asphalt
Asphalt Seal
Combined Base / Wearing Course
20/30
–
–
–
200 - 250
–
–
30/45
130 - 190
140 - 190
–
200 - 250
180 - 220
–
Voids Content in Test Core too
Cause (Aggregate)
low
Too Little Filler Too Much Filler
120 - 180
130 - 180
140 - 200
200 - 250
180 - 220
–
70/100
120 - 180
130 - 180
130 - 190
–
180 - 220
120 - 180
160/200
–
120 - 170
120 - 170
–
170 - 210
100 - 170
–
–
200 - 250
–
–
PmB 25A
–
PmB 45A
130 - 190
140 - 190
–
200 - 250
180 - 220
–
PmB 65A
120 - 180
130 - 180
140 - 200
200 - 250
180 - 220
–
low
high
low
l
l
Sand Too Fine 50/70
high
Voids Content in Aggregate too
Binder Content
l
l
120 - 180
130 - 180
130 - 190
–
180 - 220
l
Sand Too Coarse
l
l
l
Too Little Crushed Sand
l
l
l
l
Too Much Crushed Sand
l
l
l
Poor Grading of Grain Sizes
l
l
l
Polished Aggregate
l
Porous Aggregate
l
Too Little Fine Chippings
l l
120 - 180 Voids Content Too High
The lower limits refer to the unloaded mix, while paving. The upper limits refer to the mix when leaving the mixing plant.
196
l
l
Too Much Fine Chippings PmB 80A
high
Voids Content Too Low
l
l
l
l
197
6. Paving Materials in Detail
VÖGELE Booklet on Paving
6.8
Emulsion Types
Overview of Emulsion Types for Noise Absorbing Thin Overlays
How the Water Escapes from the Bitumen Emulsion
The type and handling of bitumen emulsion used is a matter of great importance when paving thin overlays. Among other things, it is important to ensure that the emulsion is applied constantly at the required rate over the entire surface so that the water contained in the emulsion can evaporate.
1. Prepared base in the form of a milled surface or freshly paved binder course.
For this reason, a semi-permeable asphalt is normally used when paving thin overlays, as it allows the remaining moisture to escape through the asphalt‘s open structure after paving. In this way, water is extracted from the emulsion, leaving only a film of bitumen. Professionals refer to this process as "emulsion breaking".
Type of Emulsion
Nominal Content Breaking Class Bitumen in % by Weight
On Contact with the Base
C60BP1‑S
60
1
breaks rapidly
C40BF1‑S
40
1
breaks rapidly
C67BP5‑DSH‑V
67
5
breaks very rapidly
4
2. Application of bitumen emulsion by the SUPER 1800-2 with SprayJet Module. The paver operates in spray mode and applies exactly the required amount of emulsion – preheated to a temperature between 60 and 75 °C. This instantly triggers a chemical reaction known as "breaking". Water is extracted from the emulsion, leaving a solidly adhering film of bitumen.
C67BP5‑DSH‑V is a cationic polymer-modified bitumen emulsion with class 5 breaking effect, meaning that the emulsion breaks very rapidly when it comes into contact with the base. The breaking effect and high bitumen content make this emulsion ideal for paving thin overlay on spray seal, hot on hot (DSH‑V).
1
2
3. The thin overlay of porous asphalt is paved by the screed immediately after spraying. The hot mix causes more water to evaporate.
198
3 4. Any water still remaining in the emulsion can evaporate through the "open pores" in the asphalt pavement.
199
VÖGELE Booklet on Paving
200
7
Special Equipment and Special Methods
201
7.1 7.2 7.3
Spray Technology . ............................................................................................... 202 Two-Layer Paving . ............................................................................................... 208 Material Feeders .................................................................................................. 216
201
VÖGELE Booklet on Paving
7.1
7. Special Equipment and Special Methods
Spray Technology
Three major advantages: 1. Complete coverage of the existing surface with spray seal is achieved and an optimal bond of layers. This adds to a long service life of the new surfacing. 2. Vehicles on the job site never pass over the emulsion, thus no soiling of adjacent areas. 3. As separate spraying of tack coat is eliminated, less preparatory work for the job. This reduces the duration of the roadworks.
The spray paver is ideal for restoring damaged wearing courses. The wearing course is restored by paving a thin overlay on a spray seal or tack coat, hot on hot.
The SUPER 1800-2 with SprayJet Module from VÖGELE is an innovative and cost-efficient means of applying bituminous emulsion. It is used when rehabilitating roads by replacing the wearing course. Optimized for paving thin overlay on a spray seal or tack coat, hot on hot, the SUPER 1800-2 with SprayJet Module meets the highest technical, economic and ecological standards. Even for non-specialized road building contractors, the SUPER 1800-2 is an effective alternative whenever emulsion is sprayed directly before paving asphalt. The SprayJet module offers a host of technological advantages. Since the rate of spread can be set from 0.2kg/m²* upwards, for instance, the bitumen emulsion can also be applied in small volumes and at low pave speeds. A constant spray pressure of no more than 3 bar is guaranteed by the system. This minimizes spray mist and pollution, not only protecting the environment, but also the health of the machine‘s operators. The SUPER 1800-2 with SprayJet Module can be completely stripped down to a standard paver in a very short space of time. As a result, the paver can also be used at any time for "normal" road construction projects.
Paving thin overlay does not require new installation of kerbs. Particularly in municipal areas, this is often an appropriate alternative.
Just 1.2 to 2cm thick, the thin overlay cuts costs and adds to the pavement‘s longevity, due to the excellent bond between layers.
*The rate of spread per square metre must be determined as a function of the emulsion to be used. The rate of spread depends on the emulsion’s consistency and temperature when applied, and on the size of nozzles used for spraying.
202
203
7. Special Equipment and Special Methods
VÖGELE Booklet on Paving
7.1
Spray Technology
Uniform All-over Application of the Emulsion The VÖGELE SUPER 1800-2 with SprayJet Module has a maximum spray width of 6m. Five spray bars and 24 spray nozzles produce a uniform film of emulsion covering the entire surface without overlaps even when working in varying pave widths.
Designation Unit Nozzles Nozzles Nozzles Size 07 Size 10 Size 16 Spraying Pressure
2
3
3
kg/m2 0.2 - 0.5 0.3 - 0.8 0.8 - 1.6
Rate of Spread Length of Spread Area in Direction of Motion
bar
mm
35
35
The pulsed spray nozzles are controlled individually. The duration of the spray pulses is adjusted automatically as a function of the selected rate of spread, pave speed and pave width.
35
Perfectly metered rate of spread Double slotted spray nozzles ensure an outstanding spray pattern regardless of the pave speed. The rate of spread can be controlled even more effectively thanks to three nozzle sizes with different throughputs: Nozzle size 07 (approx. 70% throughput) Nozzle size 10 (approx. 100% throughput) Nozzle size 16 (approx. 160% throughput).
Blue Bars = Spray Bars
The double slotted high-quality spray nozzles guarantee perfect spraying.
The required rate of spread can be entered very easily between 0.2 and 1.6 kg/m2 on the touchscreen. The quantity applied depends on: the type of emulsion, its viscosity and the temperature when spraying. Low spray pressure and less spume thanks to larger droplets allow the paver to work neatly along kerbs and minimize the emission of emulsion vapours.
250 mm
120°
204
120°
Much like the functionality of an ink jet printer, the nozzles of the VÖGELE spray paver do not spray continuously but in pulsed operation. The frequency of the spray pulses is adjusted automatically as a function of the selected rate of spread, pave speed and pave width.
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7.1
Spray Technology
The Operating Concept
Numerous Possible Uses and Large Range of Applications
Just like the ErgoPlus® paver operating system, the SprayJet module is very easy to control and uses self-explanatory symbols. The specified rate of spread or desired emulsion temperature, for example, can thus be set very conveniently.
Whether in city centres or on motorways, the SUPER 1800-2 with SprayJet Module handles every job effectively, economically and neatly.
On the ErgoPlus® console, the controls are clearly arranged. Paver functions are easily set up via the display panel.
Resurfacing Rural Road
Conventional paving after spraying tack coat with the SprayJet module. Roadway kept open to traffic. Pave Width: 7m 2 strips of 3.5m each, paved “hot to cold“ Layer Thickness: 4.5cm Rate of Spread: 0.2kg/m² on asphalt
Resurfacing National Highway Just press the F7 key to call up the screen for the SprayJet module.
Thin overlay paved on spray seal “hot on hot“. Pave Width: 13m 3 strips of 4 - 4.5m each, paved “hot to cold“ Layer Thickness: 2cm Rate of Spread: 1kg/m² on asphalt
Resurfacing Roadway in Residential Area Press the F2 key to activate the automatics for spraying.
By pressing the F6 or F8 key, the “Start of Job“ or “End of Job“ function is selected.
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Conventional paving after spraying tack coat with the SprayJet module. Pave Width: 5m paved in 1 strip Layer Thickness: 4cm Rate of Spread: 0.35kg/m² on asphalt
Pavement Rehabilitation on Motorway Thin overlay of noise-reducing asphalt.
Pave Width: 7.6m 2 strips of 3.8m each, paved “hot on hot“ Layer Thickness: 1.5cm Rate of Spread: 0.35kg/m² on asphalt
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7.2
Two-Layer Paving
Paving "hot on hot" improves the bond between layers and produces durable road pavements.
Wide range of applications due to the use of conventional machine technology The InLine Pave® machinery developed by VÖGELE covers a vast range of paving jobs, from rehabilitation of old pavements to construction of new roads. Despite the new technology, the machines are transported to the job site in the same way as before, for only standard pavers with minor modifications are used for InLine Pave®. InLine Pave® not only allows to substantially cut times required for paving work. Thanks to the compact design of InLine Pave® machinery, paving jobs can be carried out while traffic keeps flowing. Pave widths from 3m to 8m can be realized with InLine Pave®. With this technology, main thoroughfares, country roads, trunk roads and motorways can be rehabilitated or newly built in top quality and a very short space of time.
Conventional Paving
4cm
Two-Layer Paving
Surface Course
2cm
Tack Coat
With the InLine Pave® concept, VÖGELE offer a particularly innovative paving technique specially suited for “hot on hot” paving when building compact asphalt pavements. Yet conventional road construction jobs, too, can be carried out in high quality and very economically with the VÖGELE InLine Pave® equipment. InLine Pave® places the binder course and surface course in a single pass, which not only yields a perfect bond between layers but also ensures strong interlocking of the layers. This is a fundamental requirement for the longevity of roads.
8cm
Binder Course
10cm
Tack Coat
22cm
Roadbase
22cm
InLine Pave® is based on the use of series produced machinery that undergoes just slight modification for “hot on hot” paving.
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7.2
Two-Layer Paving
Machine Technology for VÖGELE InLine Pave® Bei InLine Pave® arbeiten alle Maschinen direkt hintereinander „In line“, also in einer Linie. Die Bauweise aller Maschinen ist sehr kompakt. Der InLine Pave® Zug besteht aus drei Maschinen. Einem Materialbeschicker MT 1000-1 oder MT 3000-2 Offset, einem Binderschichtfertiger SUPER 2100-2 IP und einem Deckenfertiger SUPER 1600-2. Alternativ kann ebenso ein SUPER 1800-2 als Deckenfertiger verwendet werden.
4
210
3
2
1
SUPER 1600-2 or SUPER 1800-2 for Paving Surface Course
AB 600 High Compaction Screed in TP2 Plus Version
SUPER 2100-2 IP for Paving Binder Course
Material Feeder MT 1000-1 or MT 3000-2 Offset
A normal SUPER 1600-2 or SUPER 1800-2 is used for paving the surface course. These, too, are machines of standard design, however equipped with a water spraying system for the crawler tracks and an extra material hopper insulated against loss of heat and holding a total of 25 tonnes of mix. The extra hopper is placed inside the paver‘s material hopper.
The AB 600 High Compaction Screed in the TP2 Plus version, based on the unique VÖGELE pulsed-flow hydraulics, is equipped with two pressure bars. The screed is the technological gem of the InLine Pave® technology. The binder placed and compacted by the AB 600 TP2 Plus features such a high density that the paver for surface course, following behind, can travel on the binder layer.
The SUPER 2100-2 IP for placing binder course is a slightly modified machine of standard design, fitted with a special transfer module for the surface course mix. The paver’s task is to place binder course of high density and with high resistance to deformation. The VÖGELE SUPER 2100-2 IP comes with a special AB 600 Extending Screed in the TP2 Plus version for compaction at the highest level.
The material feeder is the first machine involved in the paving process. It receives binder and surface course mixes supplied by feed vehicles and conveys the mix, by turns, either directly into the large material hopper of the paver for binder course or, via a transfer module, into the material hopper of the paver for surface course.
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7.2
7. Special Equipment and Special Methods
Two-Layer Paving
The Advantages of InLine Pave® Technology at a Glance 1. Greatest Evenness The conventional method of road construction is ideal for producing pavements of greatest evenness. Base course, binder course and surface course are laid in three passes. The “self-levelling” behaviour of the paver’s screed ensures that the evenness is improved from layer to layer. InLine Pave® translates 100% of this principle into reality, despite paving “hot on hot“. Thanks to VÖGELE High Compaction Technology installed in the screed, the binder course reaches a density beyond 98%, as a function of mix composition. Just as if that layer had been compacted by rolling. In other words: When applying InLine Pave®, the surface course is paved “hot on hot“ on a binder layer which, in terms of evenness and density, is on a par with a binder layer compacted in the conventional way. InLine Pave® does not make special demands on the evenness of the base course. 2. Use of Conventional Rollers With VÖGELE InLine Pave®, the precompaction of the binder course achieved by the paver is so high that medium-weight rollers can follow right behind the screed to produce the final density. InLine Pave® does not call for a gradual compaction of binder and surface courses by light and heavy rollers working in echelon. This reduces the risk of destroying the pavement’s evenness behind the paver. VÖGELE High Compaction Technology applied for InLine Pave® attains such a high degree of precompaction that the number of roller passes required for the final density is reduced substantially. Especially when using HAMM rollers with oscillation, a perfect final density is achieved after just a few passes. The gentle compactive action of HAMM rollers with oscillation is ideal for thin surface layers like the ones placed with InLine Pave®. 3. Clear Separation of Layers The high precompaction of the binder course precludes blending of binder and surface course mixes. A clear separation of layers results, which allows a high-quality surface course to be achieved in the specified thickness and with optimal surface finish. In addition, measurements of layer thickness can be carried out at any point while paving. This considerably facilitates monitoring of the layers for correct thickness.
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InLine Pave® achieves excellent monolithic interlocking of binder and surface courses. At the same time, VÖGELE High Compaction Technology provides for a clear separation of layers.
4. H igh Productive Utilization through Use of Machines Close to Standard Design The material feeder and the paver for surface course forming part of the InLine Pave® train can be employed for conventional paving jobs at any time, without a need for conversion. The transfer module of the SUPER 2100-2 IP, used for placing binder course, mounts or demounts in just a few hours. As a result, every machine of the InLine Pave® train is available for conventional paving applications at all times. This enhances productive utilization of the contractor’s equipment pool. 5. P lacing Base Course with the SUPER 2100-2 IP The SUPER 2100-2 IP with the AB 600 High Compaction Screed in the TP2 Plus version can also be used as a stand-alone paver for placing high-density base course. The special feature here is that single-layer construction is possible. Depending on the mix to be placed, an 18cm base, for instance, can be built in one pass instead of two layers of 9cm each. This saves time and money. For tough jobs like this, the pressure for the pressure bars of the VÖGELE High Compaction Screed is infinitely variable up to 110 bar. 6. E asy Operation for High Process Reliability The operation of all InLine Pave® machines is to a large extent identical with ordinary paving jobs. Also as far as grade and slope control is concerned, the paving teams can fall back on their knowledge gained from jobs with conventional VÖGELE equipment.
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7.2
Two-Layer Paving
The Wide Range of InLine Pave® Applications
214
Pavement rehabilitation for motorway, pave width 4m: Rehabilitation of lorry lane. Traffic kept flowing on the adjacent lane.
Pavement rehabilitation for motorway, pave width 3.75m: Rehabilitation of lorry lane. Ambient temperature 0 °C.
Pavement rehabilitation for federal highway, pave width 2 x 3.2m: Rehabilitation in single-lane width. Traffic kept flowing on the adjacent lane.
Pavement rehabilitation for motorway, pave width 4.7m: The roadworks on the busy motorway were carried out at night.
Pavement rehabilitation for motorway, pave width 7.5m: Two-layer paving of porous asphalt (ZWOPA).
Pavement rehabilitation for motorway, pave width 7.5m: Rehabilitation in two-lane width. Layer thickness for binder and surface courses 10cm + 2cm.
Pavement rehabilitation for rural road, pave width 5.5 - 7m: 9.5cm binder course and 2.5cm surface course were paved in 12-hour shifts – no problem for the InLine Pave® train.
Pavement rehabilitation for national road, pave width 3.75 - 5.25m: Rehabilitation in single-lane width. Traffic kept flowing on the adjacent lane. Slope of 2%. Referencing from the milled base using the Big MultiPlex Ski allows paving to the highest standards of evenness.
New construction of motorway, pave width 5m: Before placing binder and wearing courses, the roadbase was built with the SUPER 2100-2 IP.
Pavement rehabilitation for rural road, pave width 7.5m: During the pavement rehabilitation work, the road was closed to traffic. For the binder course, grade and slope control by means of the VÖGELE Big MultiPlex Ski referencing from the milled base. Slope up to 3.5% on curved sections. Crown set to 2.5%.
New construction of federal highway, pave width 7.5m: Two-layer paving between 6 bridges. On the bridge decks asphalt was placed by the paver for surface course. VÖGELE Big MultiPlex Ski used for grade and slope control.
Pavement rehabilitation for cross-town link, pave width 2 x 3.2m: Rehabilitation of 950m section in single-lane width. Traffic kept flowing on the adjacent lane. Short set-up time of just 2 hours for the basic configuration allows economical paving of short stretches.
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7.3
Material Feeders
MT 3000-2 Offset
MT 3000-2
C ontinuous, non-contacting supply of mix to pavers ensures maximum paving quality. High-performance feeder concept in combination with the large receiving hopper holding 11 tonnes allows even large mix lorries to be emptied in just 60 seconds.
216
Anti-collision protection and reliable distance control. ErgoPlus® operating concept offers an excellent all-round view and allows easy and safe operation. High conveying capacity of 1,200 tonnes/h.
C ontinuous, non-contacting supply of mix to pavers ensures maximum paving quality.
The conveyor can be pivoted to the left or right by 55°, opening up a wide range of diverse applications.
High-performance feeder concept in combination with the large receiving hopper holding 11 tonnes allows even large mix lorries to be emptied in just 60 seconds.
ErgoPlus® operating system allows safe and easy one or two-man operation.
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7.3
Material Feeders
Conveying Capacity
55
60
Extremely Powerful in New Fields of Application
5
50
10
45
15
40 55 35 50
20 sec 60 255 30 10
45
15 60 4055 sec 5 20 50 35 2510 30 15
45
40
20
sec 35
30
25
Feeding the paver from the side, e.g. when laying base course material in deeply milled out strips with no possibility for a feed lorry to manœuvre.
0 seconds: The mix lorry manœuvres up to the feeder. 55
60
5 10
50
15
45
20 sec 60 55 255 35 30 10 50
40
15 60 4055 sec 5 20 50 35 2510 30 15 45 45
40
20
sec 35
30
25
30 seconds: Thanks to the high-performance feeder concept, more than half of the 25 tonnes has already been unloaded.
55
60
As the conveyor can be pivoted through 55°, left or right, and can be precisely controlled, it is ideal for backfilling all kinds of trenches. The maximum distance from the outer edge of the feeder to the discharge point of the conveyor is 3.5m.
5
50
10
45
15
40
20 sec 60 55 35 255 30 50 10
45
15 60 4055 sec 5 20 50 35 2510 30 15
6 0 seconds: The feeding process is complete. The mix has been dumped into the feeder’s receiving hopper and the extra hopper of the paver. 45
40
20
sec
35
30
25
Numerous factors have to be taken into consideration to ensure that a high level of paving quality is achieved in road construction. There can be no doubt that an uninterrupted and non-contacting supply of mix to the paver is crucial to preventing any downtimes in the paving process. A feeder is thus essential to the economical achievement of high-quality results, especially on large-scale job sites. The ultra-modern MT 3000-2 Offset can do a great deal more than previous feeders. The pivoting conveyor opens up a wide range of applications that greatly improve machine utilization. And the innovative material transfer system has a top conveying capacity of 1,200 tonnes/h. This allows a 25-tonne feed lorry to be emptied in 60 seconds flat.
Quick and economical filling of the cavities in motorway safety barriers.
Pavers can be fed from the side in all those places where normal feed with mix is not possible, e.g. when surfacing footpaths or cycle paths.
The MT 3000-2 Offset is a highly advanced machine from the new VÖGELE PowerFeeder generation. It is characterized by an innovative feeder concept with economical consumption and compact dimensions.
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8
Index
A Additives . .............................................. 180, 183 Amount of Subsequent Compaction by Rolling . .................................... 30, 92, 100ff., ...................................................... 106, 125, 132ff. Asphalt Base, Binder and Wearing Course . ............................... 174ff. Asphalt Thickness Measuring Instrument ... 137 Augers ............................. 11, 46, 108, 126, 134, 144, 155ff., 165, 167 Auger Blade ............................. 155ff., 165, 167 Auger Height ............. 126, 134, 156, 165, 167 Auger Speed .................................................. 126 Auger Tunnel ....................................... 11, 165ff. Automated Grade and Slope Control ....................... 92, 116, 118, 119, ............................................. 125, 144, 150ff., 162 Automatic Steering Control ....................... 110
B Base . .......................... 15, 44, 75, 104ff., 112ff., ............................................ 118, 150ff., 174, 187, ......................................................... 191, 198, 215 Base Course . ............................... 26, 27, 35, 68, 159, 212ff., 219 Basic Screed .......................... 23, 44, 47, 50, 55, ...................................... 58ff., 61, 63, 65, 82, 126, ................................................. 152, 155, 162, 170 Basic Width . .................................... 62 - 65, 215 Bevel Irons ........................................................ 77 Big MultiPlex Ski .................. 111, 115ff., 214ff.
220
Bitumen .......................... 104ff., 107, 130, 140, ....................................... 160, 169, 171, 180, 185, ............................................. 186, 190, 192, 202ff. Bolt-on Extensions ............ 36ff., 44ff., 51 - 60, .................................................... 63, 65, 150 - 157 Bond of Layers . ................. 24ff., 141, 203, 208 Bracing ....................................................... 60, 61 Breaking of Emulsion . ............................. 198ff.
C Calculation of Average ....................... 114, 118 Centre Auger Bearing ...... 144, 155ff., 165, 167 Cleaning . ........................ 49, 80, 105, 128, 131, ............................................. 134ff., 144, 156, 169 Combined Base and Wearing Course . ................ 93, 176ff., 185 Compaction ............... 11, 24, 27, 30, 35ff., 54, ............................................... 68ff., 73, 88, 90, 92, ............................................ 100, 107, 125, 127ff., .................................................. 133, 138ff., 149ff., ...................................................... 153ff., 171, 212 Compacting Systems . ... 11, 30, 63, 65, 69, 88, ............................................. 90, 107, 125, 133, 171 Conveying Capacity ............................ 216, 218 Conveyors . ............................................ 126, 164 Cracks from Rolling ...................................... 142 Crawler Tracks . ............................................. 14ff. Crown .................... 23, 38, 63, 65, 80, 155, 214 Crushed Grains ..................... 88, 107, 132, 171 Curves . ......................................... 23, 114ff., 117
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VÖGELE Booklet on Paving
D
H
Deformation .................................................. 175 Direction of Paving . ............................ 120, 142 Distance ...................... 40, 71ff., 118, 123, 127, ......................................... 133, 156, 162, 167, 219
Head of Mix in Front of Screed .......... 60, 89, 126, 154, 165 Heating Power . ...................................... 78, 156 Heating Rods ......................... 50, 63, 65, 78, 79 Height Adjustment......... 11, 23, 38, 40, 42, 73, ......................................... 74, 80, 150ff., 163, 170 High Compaction Screed .... 25, 46, 68, 210, 211 Hopper Sides ................................................. 164 “Hot to Cold” Paving .............. 127ff., 132, 207 “Hot on Hot“ Paving . ............. 25, 68, 208, 212 Hydraulic Rams for Pressure Bars ................ 71
....................................... 129, 132, 135, 150, 154, .................................... 159, 165, 171, 178, 187ff. ................................................................... 192, 207 Level Regulating Layer ....................... 106, 171 Level Regulating Measures ........................ 191 Limiting Plates for Auger Tunnel .................. 108ff., 126, 144, 165 Load Bearing Capacity ........... 12, 88, 92, 105, .......................................... 143, 153, 159ff., 174ff. Longitudinal Direction ................ 89, 129, 170 Longitudinal Joint ............................... 127, 132 Longitudinal Profile ..................................... 162 Loss of Heat . .................................................... 78
I
M
Imprint(s) ............................. 142, 150, 153, 170 Inline Pave® ............................ 25, 68, 208 - 215 Irregularities . ............ 9ff., 14ff., 44, 75ff., 90ff., ......................................... 95, 105, 117, 134, 158ff., ............................................. 161ff., 175, 187, 191
Material Hopper ............ 110, 144, 157, 164, ................................................................... 166, 216ff. Material Transfer .................................. 164, 218 Measuring Range ............................ 112ff., 115 Mixing Plant . ....................... 98, 104, 122, 135, ...................................................... 145, 156ff., 169 Mix Properties .......................................... 12, 88 Mix Temperature . ....... 88, 104, 137, 160, 196
E Eccentric Shaft . ........................................ 30, 70 Emulsion Types ............................................. 198 End Plate . ..................... 108ff., 132, 135, 151ff.
F Feed Vehicle .................. 11ff., 125, 140ff., 144, ........................................ 149, 153, 183, 195, 218 Feed with Mix ....................... 10ff., 88, 98, 135, ...................................................... 144, 166, 216ff. Filling Level .................................................... 168 Fishplates . ...................................................... 102 Frequency . ....................................................... 30 Function Check ........................................ 78, 98
G Generator .................................................. 69, 78 Generator Temperature . ............................... 79 Grade and Slope ................. 13, 118, 120, 125, .......................................................... 135, 213, 215 Grade Sensor ................................................. 116 Grain Size ................................................. 88, 190
222
J Joint Face ............................................... 127, 128 Joints ..................................................... 73, 127ff.
L Laser . .................................... 111, 113, 119, 121 Laydown Rate . .............................................. 122 Layer Thickness ............. 11, 12, 22, 30, 35, 53, ............................................ 69, 76ff., 79, 88ff., 90, ........................................... 93, 100ff., 119ff., 129,
N NAVITRONIC® .................................... 111, 120ff. NIVELTRONIC® . ............... 116, 118, 121, 150ff. Non-contacting Feed with Mix ............. 216ff.
O
Option ..................................... 11, 62, 74, 77, 79 Overlapping ................................. 128, 139, 204
P Parameters ................. 85, 87, 89, 92, 100, 157 Patches of Mix in Surface Texture ............. 169 Paving . ...................................................... Paved Cold . .................................................... 184 Paving Errors .............................. 148, 158 - 171 Paved Hot ...................... 24, 184, 188ff., 196ff., ...................................................... 202ff., 207, 212 Paving: Points to Note ......................... 98 - 145 Paving Problems ................................ 158 - 163 Paving Thin Overlay ..................................... 198 Pave Speed . ........................ 90, 91, 125ff., 149, .......................................................... 151, 154, 205 Pave Width .................... 14, 21, 36, 52 ff., 60ff., ...................................... 63ff., 68, 70, 89, 98, 108, ....................................... 121, 126, 133, 135, 149, ................................ 152, 157, 161,170, 205, 209 Polymer Modified Bitumen ...... 185, 194, 198 Porous Asphalt ..... 177ff., 185, 194ff., 199, 214 Precompaction . ............... 11, 26, 30, 35ff., 52, ....................................... 54, 68ff., 89ff., 100, 104, ........................................ 106, 133, 140, 151, 212 Preprofilling ............................................... 105ff. Pressure Bar(s) ....... 30, 35, 47, 49, 50, 53, 68ff., ............................. 93, 144, 149ff., 154ff., 210, 213 Pre-Tension of Spring .................................... 71 Pre-Treatment . .............................................. 183 Process Safety . .............................................. 213 Push-Rollers ................................................... 144
Operating the Hopper Sides ...................... 166
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VÖGELE Booklet on Paving
Q Quality . ........................... 24, 73, 113, 122, 135, .......................................... 148ff., 187, 209, 216ff.
R Reference . ................... 110, 112ff., 116ff., 119, .......................................... 121, 123ff., 150ff., 162 Reference (Grade) . ....................................... 116 Referencing . ......................... 70, 112, 124, 157 Roller . ........................ 92, 100, 102, 104, 127ff., ................................ 130, 132ff., 138ff., 142, 149, ........................................ 152, 154, 156, 187, 212 Rotary Laser Beam .............................. 113, 119 Rules for Rolling ............................................ 142
S Scale for Layer Thickness ................... 100, 102 Screed ........................................................ Screed Arm . ............... 8, 11, 13, 115, 150, 163 Screed Assist ................................ 11, 94ff., 151, .......................................................... 154, 157, 159 Screed Float .................................. 90, 94ff., 159 Screed Float Behaviour ...... 11, 36, 54, 76, 79, ........................................................ 88ff., 101, 124, ................................................................... 161, 170 Screed Freeze . .................. 11, 90, 95, 153, 160 Screed Freeze Pressure . ....................... 94, 160 Screed Heating . ..................................... 78, 169 Screed Planing Angle ............ 11ff., 36, 54, 76, ........................................... 89ff., 95, 102, 125, 135, ................................................... 150ff., 158ff., 170
224
Screed Plate .......................... 11, 13, 30, 36, 40, ................................................... 51, 54, 60, 63, 65, ........................................................... 70ff., 79, 161 Screed Tow Points . ................. 12, 76, 124, 160 Screed Type .............................. 47, 83, 149, 160 Screed Versions for Compaction ............. 34, 52 Screed Weight ............................... 11, 153, 160 Segregation .......... 108, 150, 156ff., 164 - 169 Select Quantity of Emulsion ...................... 205 Selecting Sensor ................................ 111 - 121 Sensor . ..................... 111ff., 114ff., 118, 123ff., .......................................... 126, 144, 150ff., 156ff. Service-Friendliness . .................. 48, 80ff., 144 Setting Pressure ............................................ 159 Setting up the Screed . .............. 38, 40ff., 60ff. Set-Up, Settings .......... 93, 100, 133, 135, ............................................. 159, 168, 171 Set-Up of Extending Screed . ............... 38 - 47 Set-Up of Fixed-Width Screed .................. 60ff. Set-Up of Pressure Bar(s) ..................... 71, 150 Set-Up of Tamper . .......................................... 70 Set-Up of Tamper Shield ............................... 72 Side Plate, Hydraulic ................. 73ff., 115, 144 Slope ................................ 63, 65, 105, 111, 119, ............................................. 123, 133, 157, 214ff. Slope Sensor .............................................. 111ff. Sonic Grade Sensor .................................. 115ff. Spirit Level, Digital ....................................... 136 Sprayed Quantity of Emulsion ..... 202, 205ff. Spraying Emulsion .............................. 128, 203 Spray Nozzles . ........................................... 204ff. Spray Seal .................................... 24, 198, 202ff. Spreading Emulsion.............................. 198, 204 Steering . ....................... 8, 110, 134,138ff., 142
Steering Guide .............................................. 110 Stone Mastic Asphalt .......... 177ff., 184ff., 196 Strike-Off Plate ......... 46, 108ff., 126, 144, 165 Strip in Middle of Pavement ...................... 167 Strip Steel ......................................................... 72 Stroke .................. 9, 68, 70, 90, 93, 151ff., 159 Surface ...................... 30, 36, 54, 79, 90ff., 103, ................................... 105, 107, 127, 135, 140ff., ................................ 150, 155ff., 161ff., 164, 169, ....................................... 171, 174, 186, 188, 190, ................................................. 192, 194, 195, 212 Surface Texture . ............... 36, 79, 90, 169, 171
T Tack Coat . .............................................. 105, 129 Tamper ............................ 11, 30, 32, 34ff., 50ff., ........................................ 69ff., 72, 78, 82, 88, 91, .......................................... 144, 154ff., 160ff., 169 Tamper Height ................................................ 70 Tamper Shield . ................................................ 68 Tamper Speed ......................... 68, 90ff., 149ff., ................................................................. 153ff., 169 Tamper Stroke ................................... 68, 70, 90, .......................................................... 154, 157, 159 Teflon Tapes ................................................... 162 Telescoping Tubes ....... 48, 64, 80, 150ff., 162 Temperature ..................... 88ff., 104, 114, 125, ........................................ 135, 137, 181, 199, 205 Tolerance ........................................................ 112 Torsion . ............................................................. 90 Tow Point Rams . ............... 11, 13, 38, 91, 100, .......................................................... 102, 144, 158 TP . .................................................. 34ff., 47, 50ff.
Tracked Paver . ........................................ 14, 158 Tracked Undercarriage ............................... 14ff. Traction .......................................................... 14ff. Traction Drive ........................................... 11, 14 Traction Main Switch ............................ 95, 125 Transport ................................. 25, 98, 104, 110, ..................................................... 122, 155ff., 164, .......................................................... 183, 209, 211 Transverse Joint ................................... 127, 129 Transverse Slope ........... 63, 65, 105, 111, 119, ............................................. 123, 133, 157, 214ff. Transverse Strip . ........................................... 166 Troxler Probe . ................................................ 143 Trucking ............................................................ 16 TV . ............................................................ 34, 52ff. Type of Paver ...................................... 13, 63, 65
U Undulations ....................................... 46, 70, 83, ...................................................... 113, 116, 150ff.
V Valves in Hydraulic Rams ..................... 95, 151 Vibration .................... 30, 34, 63, 65, 82ff., 142
W Wedge .................................................... 137, 143 Wheeled Paver ............................................. 16ff. Weather . ......................................... 89, 104, 122 Weight ............................. 68, 95, 138, 140, 142, ................................................. 153, 160, 170, 183
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Notes
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Notes
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Notes
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®
ErgoPlus, InLine Pave, NIVELTRONIC, NIVELTRONIC Plus, NAVITRONIC, NAVITRONIC Plus, RoadScan and V-TRONIC are registered Community Trademarks of JOSEPH VÖGELE AG, Ludwigshafen/Rhein, Germany. PCC is a registered German Trademark of JOSEPH VÖGELE AG, Ludwigshafen/Rhein, Germany. NIVELTRONIC Plus and NAVITRONIC Plus are trademarks registered in the US Patent and Trademark Office to JOSEPH VÖGELE AG, Ludwigshafen/Rhein, Germany. Legally binding claims cannot be derived from written information or pictures contained in this brochure. Pictures may include optional extras. We reserve the right of technical or design alterations.
2280299 EN/10.12
VÖGELE Booklet on Paving
Telephone: +49 (0)621 8105 0 Fax: +49 (0)621 8105 461 www.voegele.info
VÖGELE Booklet on Paving
JOSEPH VÖGELE AG Joseph-Vögele-Straße 1 67075 Ludwigshafen · Germany
[email protected]
