IRC 37-2012 Venkats Presentation Flexible Pavement Design Soft Copy. This copy can be conveniently read on computers, T...
IRC:37-2012 VENKAT’S PRESENTATION on DESIGN of FLEXIBLE PAVEMENTS
V. VENKATA NARAYANA DEPUTY EXECUTIVE ENGINEER (R&B), vvnhighways.blogspot.in vvnhighways.blogspot.in
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IRC:37 2012 vis-a-vis IRC:37-2001 First 4 slides are for the Engineers well versed with IRC:37:2001. Amateur can skip the first 4 slides. 1) DESIGN PRINCIPLE :: i. IRC:37-2012 :: APPROACH of DESIGN :- MECHANISTIC EMPIRICAL . Traffic 2-30 msa :- Design Life Lasts till which ever following takes place earlier. FATIGUE CRACKING in Bituminous surfacing limited to 20% of pavement area or RUTTING in Pavement reached terminal rutting (20 mm) in 20% of length. Traffic 30-150 msa :- Design Life Lasts till which ever following takes place earlier. FATIGUE CRACKING in Bituminous surfacing limited to 10% of pavement area or RUTTING in Pavement reached terminal rutting (20 mm) in 10% of length.
ii. IRC:37-2001 :: APPROACH of DESIGN :- MECHANISTIC EMPIRICAL . Traffic 1-150 msa :- Design Life Lasts till which ever following takes place earlier. FATIGUE CRACKING in Bituminous surfacing limited to 20% of pavement area or RUTTING in Pavement reached terminal rutting (20 mm) in 20% of length. vvnhighways.blogspot.in
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IRC:37 2012 vis-a-vis IRC:37-2001 2) PAVEMENT COMBINATIONS :: IRC:37-2012 :- FIVE different COMBINATIONS :: Surfacing with Bitumen and Bases and Sub-Bases with un-bound and bound materials ( Cementitious) . IRC:37-2001 :- ONLY ONE COMBINATION :: Surfacing with Bitumen and Bases and Sub-Bases with un-bound materials.
3) SYSTEM of UNITS :: IRC:37-2012 :- IS SYSTEM. IRC:37-2001 :- CGS SYSTEM .
4) PAVEMENT DESIGN PROCEDURES :: IRC:37-2012 :- TWO Procedures 1) Using IITPAVE & 2) Design Charts &Catalogues. IRC:37-2001 :- ONE Procedures Using Design Charts & Catalogues .
5) ANNUAL TRAFFIC GROWTH RATE :: IRC:37-2012 :- 5.0 %. IRC:37-2001 :- 7.5 % . vvnhighways.blogspot.in
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IRC:37 2012 vis-a-vis IRC:37-2001 6) CBR – The SUBGRADE Strength :: i. CBR for DESIGN :: IRC:37-2012 :- EFFECTIVE CBR -> Obtained by combining Subgrade CBR & Embankment CBR. IRC:37-2001 :- CBR of SUBGRADE Only .
ii. CBR Minimum for SUBGRADE :: IRC:37-2012 :- 8 % CBR of SUBGRADE. IRC:37-2001 :- 2 % CBR of SUBGRADE .
iii. CBR Minimum – Maximum for Design :: IRC:37-2012 :- 3-15 % EFFECTIVE CBR . IRC:37-2001 :- 2-10 % CBR of SUBGRADE.
7) BITUMINOUS GRADING :: IRC:37-2012 :- VISCOSITY GRADING. IRC:37-2001 :- PENETRATION GRADING.
8) NAMING PAVEMENT LAYERS :: IRC:37-2012 :- Wearing Course, Layer below Wearing Course, Base Layer, Sub-base Layer. IRC:37-2001 :- Wearing Course, Binding Course, Base Course, Sub-base Course. vvnhighways.blogspot.in
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IRC:37 2012 vis-a-vis IRC:37-2001 9) PAVEMENT LAYER THICKNESS in Base & Sub- base layer combinations :: i. TOTAL THICKNESSES :: IRC:37-2012 :- Min:380+(20) mm to Max: 850 mm ( Arithmetic sum of all layers) . IRC:37-2001 :- Min:375+(20) mm to Max: 975 mm (Clearly given in the Code).
ii. GSB THICKNESSES :: IRC:37-2012 :- 100 – 380 mm. IRC:37-2001 :- 150 – 460 mm.
iii. WMM THICKNESSES :: No change. IRC:37-2012 :- 225 – 250 mm. IRC:37-2001 :- 225 – 250 mm.
iv. LAYER BELOW WEARING COURSE THICKNESSES :: IRC:37-2012 :- 30-170 mm. (Only DBM). IRC:37-2001 :- 0 – 215 mm. ( BM or DBM).
v. WEARING COURSE THICKNESSES :: IRC:37-2012 :- 20 -- 50 mm . (, SDBC, of BC). IRC:37-2001 :- 20 -- 50 mm . (PC, SDBC, of BC). vvnhighways.blogspot.in
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COMPONENTS OF ROAD ROAD WAY FORMATION
CARRIAGEWAY
SHOULDER PAVEMENT SUBGRADE EMBANKMENT
G.L
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PAVEMENTS • Pavement : Pavement is a structure. 1. It consists of superimposed layers of selected and processed materials. 2. It is placed on a Sub grade. 3. It supports the applied traffic loads and distributes them to the soil foundation.
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ESSENTIL REQUIEMENT OF PAVEMENTS
• 1) STRUCTURAL PERFORMANCE – A PAVEMENT SHOULD BE • (i) STRONG enough to resist the stresses imposed on it and • (ii) THICK enough to distribute the external loads on the earthen subgrade.
• 2) FUNCTIONAL PERFORMANCE – A PAVEMENT SHOULD HAVE • • • •
(i) Riding quality, (ii) Surface friction for skid resistance, (iii) Low noise and (iv) Good Geometrics. vvnhighways.blogspot.in
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TYPES OF PAVEMENTS 1) FLEXIBLE PAVEMENTS, 2) RIGID PAVEMENTS, 3) COMPOSITE PAVEMENTS, i.
Surface course is Bituminous & Base Layer is RIGID (PCC).
ii. Surface course is RIGID (PCC) & Base Layer is Bituminous.
4) SEMISEMI-RIGID PAVEMENTS and 5) PRECAST PREPRE-STRESSED CONCRETE PAVEMENTS.
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ELEMENTS of FLEXIBLE PAVEMENTS as per MoRT&H
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ELEMENTS of CONCRETE PAVEMENTS as per MoRT&H
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1) FLEXIBLE PAVEMENTS 1. Consists THREE Layers. 2. It has low FLEXURAL strength. 3. Transfers the traffic loads by DISPERSION.
Bituminous Wearing Course Layer below Wearing Course
BITUMINOUS SURFACINGS
BASE LAYER SUB-BASE LAYER SUB GRADE (FOUNDATION) vvnhighways.blogspot.in
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FLEXIBLE PAVEMENTS- LOADS & STRESS STRESSESS ON DIFFERENT LAYERS
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2) RIGID PAVEMENTS
1. These consist of only TWO Layers. 2. Transfers the traffic loads by FLEXURE.
CC WEARING COURSE
SUB-BASE LAYER SUB GRADE
Sub-base may be
DLC/ PCC/ WMM/WBM
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3) COMPOSITE PAVEMENTS • Surface course is BITUMINOUS.
• Surface course RIGID (PCC)
• Base/ Sub-base is RIGID (PCC).
• Base/ Sub-base is BITUMINOUS.
BITUMINOUS WEARING COURSE
RIGID (CC) WEARING COURSE
RIGID BASE LAYER
BITUMINOUS BASE LAYER
SUB GRADE
SUB GRADE
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4) SEMI-RIGID PAVEMENTS
COMPOSITE PAVEMENT MATERIAL includes CONSISTING OF • Porous asphalt concrete (PA) with air voids between 25-30% (by Marshall mix design volume). • Filled or flooded by special formulated high performance polymer modified cement mortar material in to above Porous asphalt concrete wearing course. SEMI-RIGID WEARING COURSE
BASE LAYER SUB GRADE vvnhighways.blogspot.in
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5) PRECAST PRE-STRESSED CONCRETE PAVEMENTS.
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DESIGN OF FLEXIBLE PAVEMENTS
TWO CODES for DESIGN Village Roads and Rural Roads :: Traffic Less than 450 CVPD). IRC:SP:20-2002 (Rural Road Manual). IRC :SP72-2007 (Guide lines for the design of flexible pavements for low volume Rural Roads ).
Expressways, NH, SH, MDR:: Traffic Greater than 450 CVPD (2 msa to 150 msa). IRC:37-2012 (Guide lines for the design of flexible pavements). vvnhighways.blogspot.in
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IRC:37-2012 GUIDELENES FOR THE DESIGN OF FLEXIBLE PAVEMENTS
This code is based on MECHANISTIC EMPERICAL Approach. Design life of pavement to last till the earliest of the following happening. A. Up to 30 msa. I. FATIGUE CRACKING in Bituminous surfacing limited to 20% of pavement area or II. RUTTING in Pavement reached terminal rutting (20 mm) in 20% length. B. Up to 150 msa. I. FATIGUE CRACKING in Bituminous surfacing extended to 10% of pavement area or II. RUTTING in Pavement reached terminal rutting (20 mm) in 10% length
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DESIGN OF FLEXIBLE PAVEMENTS Design of FLEXIBLE PAVEMENTS involves the interplay of several variables like Wheel Loads. Traffic. Climate. Terrain. Subgrade condition.
MAIN PARAMETERS FOR DESIGN . DESIGN TRAFFIC .- (STRESS) Cumulative number of Standard Axles.
CBR value of Subgrade.-(STRENGTH). vvnhighways.blogspot.in
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TRAFFIC TERMS - Definition in code.
IRC:37 Considers traffic in terms of :: STANDARD AXLE = 80 KN DESIGN LIFE = Period in which the cumulative number of standard axles carried by the pavement. CVPD :: Commercial Vehicles Per Day Vehicle having LADEN weight more than 30 KN.
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PARAMETERS for DESIGN TRAFFIC For estimating the DESIGN TRAFFIC, information required :: i. INTIAL TRAFFIC :: After construction (before the road is opened to traffic) in terms of CVPD. ii. TRAFFIC GROWRT RATE :: % of Annual increment in traffic. iii. DESIGN LIFE :: in number of years. iv. VEHICLE DAMAGE VACTOR :: Due to deviation from Standard Axle loads v. DISTRIBUTION of commercial traffic over the carriageway.
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TRAFFIC I) INITIAL TRAFFIC :: Only the number of commercials (W>30 KN) and The Axle-Loading of Commercial Vehicles are considered. The initial daily average traffic flow based 7 days X 24 hours classified counts. II ) TRAFFIC GROWTH RATE :: Traffic growth rate is estimated :: By studying the past trends of traffic growth and By establishing economic models as per procedure out lined in IRC:108. The code recommends average annual growth rate as 5.0 % (In case adequate data is not available). vvnhighways.blogspot.in
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iii) DESIGN LIFE Definition :: Design life of a pavement is the CUMULATIVE NUMBER of “standard axles” that can be carried before strengthening of pavement is necessary. DESIG LIFE for :: Express ways & Urban Roads. -- -- -- 20 yrs. National Highways & State Highways – 15 yrs. Other category of roads -- -- -- -- 10 to 15 yrs.
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iv) VEHICLE DAMAGE FACTOR
Definition :: It is an equivalent number of STANDARD AXLE per COMMERCIAL VEHICLES. STANDARD AXLE = 80 KN.
It is a multiplier to convert COMMERCIAL VEHICLES of different axle loads and configuration to STANDAD AXLE. COMMERCILA VEHICLE * VDF = STANDARD AXLE. vvnhighways.blogspot.in
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iv) VEHICLE DAMAGE FACTOR The following equations used for computing equivalency factors for Single, Tandem and Tridem axles.
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iv) VEHICLE DAMAGE FACTOR- Example
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iv) VEHICLE DAMAGE FACTOR- Example
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iv) VEHICLE DAMAGE FACTOR- Default Values THE DEFAULT VALUES of V.D.F. Stipulated in code Where Sufficient information on axle loads is not available and The small of the project does not warrant axle load survey.
Examples 100 CVPD = 150 Standard Axles. 1000 CVPD = 3500 Standard Axles. 2000 CVPD = 9000 Standard Axles.
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v) LANE DISTRIBUTION FACTOR Distribution of commercial traffic by LANE. DIRECTION. Necessary in arriving realistic total equivalent standard axle load used in design.
Types of Carriageways Single Lane carriageway ( No median of divider). Dual lane carriageway ( With Median or Divider).
Types of Lanes Single - Lane (only in single carriageway). Two – Lane. Three – Lane (only in dual carriageway). Four – Lane .
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v) LANE DISTRIBUTION FACTOR SINGLE CARRIAGEWAY ROADS
DUEL CARRIAGEWAY ROADS
100 %
75 %
75 %
60 %
40 %
45 %
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v) LANE DISTRIBUTION FACTOR SINGLE CARRIAGEWAY ROAD Sno
Number of Lanes
Width
L.D.F. (%)
1
Single – Lane
3.75 m
100
2
Two – Lane
7.00 m
75
3
Four – Lane
14.0 /15.0
40
7.0 + 7.0
75
DUAL CARRIAGEWAY ROAD 1
Two – Lane
2
Three – Lane
10.5 + 10.5
60
3
Four – Lane
14.0 + 14.0
45
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Estimation of TRAFFIC- Initial
Suppose TRAFFIC in the year of CENSUS is (CVPD) - - - - - - - -
P (1 + r )
TRAFFIC after ONE year (CVPD) - - - - - - - - - - - - - - - - TRAFFIC after TWO years (CVPD) -TRAFFIC after THREE years (CVPD) - - -
P
P (1 + r )(1 + r ) = P (1 + r ) 2 P (1 + r )(1 + r )(1 + r ) = P (1 + r ) 3
----- -- - - - - - - - - - - - - - - - - - -- - - - - - - - - --------------- - - - - - - - - - - - -- - - - - - - - - - - - - - - - TRAFFIC after x years (CVPD) - - -
P(1+ r)(1+ r)(1+ r) − −x = P(1+ r)x = A
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Estimation of TRAFFIC- Cumulative Suppose TRAFFIC in the year of COMPLETION is (CVPD) - - - - - TOTAL number of vehicles in FIRST year (CVPD) -- - TOTAL number of vehicles in SECOND year (CVPD) TOTAL number of vehicles in THIRD year (CVPD)
365
A * A
365 * A * (1 + r ) 365 * A * (1 + r ) 2
=== === === === === === === === === === === ====
TOTAL number of vehicles in ‘n th’ year (CVPD) CUMULATIVE TRAFFIC for
n years (CVPD)
(By adding the TRAFFIC from FIRST to n th year)
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365 * A * (1 + r ) ( n −1 )
[
365 * A * (1 + r ) n − 1 r
] 34
Estimation of TRAFFIC – ABSTRACT FORMULA CUMULATIVE NUMBER OF STANDARD AXLES TO BE CARRIED IN THE DESIGN PERIOD IN TERMS OF msa (Millian Standard Axles)
N =
[
365 * ( 1 + r ) n − 1 r *1000000
]* A * D * F
A = Initial Traffic. r = Growth Rate. D = Lane distribution factor. n = Design life in years. F = Vehicle Damage Factor. vvnhighways.blogspot.in
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SUBGRADE Definition :: It is the top 500 mm of FORMATION and is FOUNDATION to the pavement. The Subgrade is in infinite layer in contact with the ground. It should be well compacted. The Subgrade is constructed with Local materials Without stabilization or With stabilization using stabilizers. .
Density :: The DRY DENSITY not less than 1.75 gm/cc. Strength :: The STRENGTH of subgrade is assessed in terms of CBR ( California Bearing Ratio).
Minimum = 8% The CBR should be found on remolded samples in the lab at the weakest condition under the road after construction. vvnhighways.blogspot.in
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SUBGRADE
Compaction :: 97.0 % of Dry density achieved with heavy compaction (MODIFIED proctor density). For Expressways, National Highways, State Highways, Major District Roads, Other Heavy trafficked roads.
97.0 % of Dry density achieved with normal compaction (STANDARD proctor density). Rural roads . vvnhighways.blogspot.in
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CBR- California Bearing Ratio The California Bearing Ratio test is a penetration test meant for the evaluation of SUBGRADE strength of roads and pavements. It is an EMPIRICAL test. One CBR value is equal to average of three specimen tests. The test should be performed on remoulded samples in the laboratory. The sample should be remoulded at placement density & moisture content. The moisture content should be Ascertained from compaction curve at lab or Can be based on field data of existing in-service pavements.
MINIMUM value of CBR for Subgrade = 8% Embankment below Subgrade = 1.5%. vvnhighways.blogspot.in
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EFFECTIVE CBR In case there is significant difference between the CBRs of the select SUBGRADE and EMBANKMENT below Subgrade soils, the Design should be based on EFFECTIVE DBR. The EFFECTIVE CBR of subgrade can be determined from the adjacent figure. vvnhighways.blogspot.in
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EFFECTIVE CBR - EXAMPLES EXAMPLE 1 CBR of Subgrade = 20 % CBR of Embankment = 7% Effective CBR = 15.0 % EXAMPLE 2 CBR of Subgrade = 10 % CBR of Embankment = 3% Effective CBR = 7.0 %
15.0%
7.0%
EFFECTIVE CBR MINIMUM = 3 % MAXIMUM = 15% vvnhighways.blogspot.in
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EFFECTIVE CBR - VALUES
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PRINCIPLES of PAVEMENT DESIGN PAVEMENT MODEL A Flexible pavement is modeled as an elastic multilayer structure. CRITICAL PARAMETERS FOR PAVEMENT DESIGN. i. Tensile strain at the bottom of bituminous layer-> CRACKING. ii. Vertical subgrade strain on the top of subgrade -> RUTTING
Deciding Limits. CRACKING in Bituminous Layers. RUTTING in Non-Bituminous Layers vvnhighways.blogspot.in
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FATIGUE
Definition :: Fatigue is the weakening of a material caused by repeatedly applied loads. It is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The nominal maximum stress values that cause such damage may be much less than the strength of the material. Fatigue occurs when a material is subjected to repeated loading and unloading.(Temperature also is a load).
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FATIGUE in BOTTOM Layer of Bituminous Pavement and Fatigue Life
FATIGUE With every load repetition, the tensile strain developed at the bottom of Bituminous Layer develops micro cracks. These MICRO CRACKS widen and propagate to surface beyond the following acceptable limits. The phenomenon known as FATIGUE (or fracture) of the bituminous layer. LIMITS 20 % of Area for traffic up 2 to 30 msa. 10 % of Area for traffic 30 to 150 msa. vvnhighways.blogspot.in
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RUTTING in PAVEMENT
RUTTING RUTTING is the permanent deformation in pavement usually occurring longitudinally along the wheel path. It may partly be caused by deformation in the subgrade and other non-bituminous layers. The Bituminous layers may undergo rutting due to secondary compaction. Excessive rutting greatly reduces the serviceability of the pavement. LIMITS 20 mm in 20 % of the length for traffic up to 30 msa. 20mm in 10 % of Length for traffic 30 to 150 msa. vvnhighways.blogspot.in
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Design To limit the RUTTING and the CRACKING, the pavement is designed based on elastic behavior of component layers. 1. Resilient Modulus is the measure of elastic behaviour of Subgrade and Granular bases. Resilient Modulus of Subgrade estimated from CBR of Subgrade. Resilient Modulus of Granular bases is determined from Resilient Modulus of Subgrade.
2. Elastic Modulus is the measure of strength of Bound Sub-bases. Elastic Modulus of Bound Sub-bases is determined from the unconfined compressive strength of the material.
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Design 3. Flexural strength is the measure of strength of Bound Bases. Flexural strength of Bound Bases is determined from the unconfined compressive strength of the material.
4. Resilient Modulus if the measure of elastic behaviour of Bituminous Layers. Resilient Modulus of any Bituminous mix controlled by the I. Grade of bitumen used and II. Air temperature. Design catalogues giving pavement compositions are prepared at 350C temperature.
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Design 1. The parameters to addressed in design of Pavement are i. FATIGUE leading to CRACKING and ii. RUTTING.
2. FATIGUE LIFE. i. Sub-Base --- Thickness ii. Base --- Thickness iii. Bituminous Surfacings - Thickness.
3. RUTTING. i. Sub-Base --- Thickness ii. Base --- Thickness iii. Bituminous Surfacings - Thickness and Mix Design using higher viscosity grade Bitumen or Modified Bitumen. vvnhighways.blogspot.in
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FATIGUE LIGFE
The Fatigue Life of Pavement increased THREE TIMES if i. The Bitumen content increased by 0.5 % to 0.6% above optimum bitumen content given by Marshal test, ii. Air void is reduced to the minimum acceptable level of 3 % and iii. Volume of Bitumen increased to the level of 13 %.
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PAVEMENT COMPOSITION THE COMPONENTS of FLEXIBLE PAVEMENTS ARE 1) BITUMINOUS SURFACING :: Wearing Course and/or Layer Below Wearing Course.
2)
AGGREGATE INTERLAYER :: Only for Cement Base. Aggregate Layer -- (WMM 100 mm) or SAMI
3)
BASE LAYER :: Unbound Base layer -- Granular. Bound Base layer -- Cemented or Stabilized
4)
SUB-BASE LAYER :: Unbound Sub-base layer – Granular. Bound Sub-base layer -- Cemented or Stabilized
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BITUMINOUS SURFACING – Wearing Course.
WEARING COURSES :: Catalogue of design are worked out at 350C of Bitumen. At 350C , Poisson’s ratio of Bitumen is 0.35. I. SDBC--- Semi-Dense Bituminous Concrete :: 1. Specification No :- 508 of MoRT&H (4 th Revision) 2. Traffic :- up to 5 msa. 3. Thickness :- 25, 30, 40 mm. 4. Bitumen :- VG 30 grade. II. BC--- Bituminous Concrete :: 1. Specification No :- 507 of MoRT&H (5 th Revision) / 509 of MoRT&H (4 th Revision 2. Traffic :- Above 5 msa. 3. Thickness :- 25, 30, 40, 50 mm 4. Bitumen :- VG 30 grade up to 30 msa & VG 40 grade above 30 msa. vvnhighways.blogspot.in
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BITUMINOUS SURFACING – Layer below Wearing Course.
LAYER BELOW WEARING COURSE :: Catalogue of design are worked out at 350C of Bitumen. At 350C , Poisson’s ratio of Bitumen is 0.35.
I. DBM --- Dense Bituminous Macadam ::. 1. Specification No :- 505 of MoRT&H (5 th Revision) / 507 of MoRT&H (4 th Revision). 2. Traffic :-2- 150 msa (Every traffic). 3. Thickness :- 30, 40 , 50 … 80, 85, 90 … 170 mm. 4. Bitumen :- VG 30 grade up to 30 msa & VG 40 grade above 30 msa. 5. Note :- Bitumen used for DBM should be same as used for wearing course laid over DBM. vvnhighways.blogspot.in
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AGGREGATE INTERLAYER – Aggregate Layer
1)
Cementitious base normally crack due to Shrinkage and Temperature changes even before pavement being loaded. The cracks developed in the Cementitious base reflect in Bituminous Course laid on it. To delay propagation of cracks in the Bituminous course, a crack relief layer provided between the bituminous course and Cement Base. Aggregate layer consists any one of the following
2) 3)
4) 1) 2)
Crushed aggregate 100 mm of WMM conforming to MoRT&H. Stress Absorbing Membrane Interlayer (SAMI) of elastic modified binder. vvnhighways.blogspot.in
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BASE LAYER – Unbound Base Layer -GRANULAR I. FUNCTIONS :- It serves TWO Functions. 1. Provides strength and support to the overlying pavement. 2. Protect the Subgrade from over stressing. II. MATERIALS :- Wet Mix Macadam(406), Water bound macadam, Crusher run macadam, reclaimed concrete. III.PROPERTIES of WMM :1. Gradation as per Table 400-13 of MoRT&H. 2. AIV less than 30%. 3. Flakiness Index+ Elongation Index < 35 %
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BASE LAYER – Bound Base Layer – CEMENT TREATED I. FUNCTIONS :- It serves TWO Functions. 1. Provides strength and support to the overlying pavement. 2. Protect the Subgrade from over stressing.
II. MATERIALS(403 of MoRT&H) :1. Aggregates stabilized with Cement. 2. 7 day minimum strength 4.5 Mpa. 3. 28 day minimum strength 7.0 Mpa. III.PROPERTIES of Cement treated BASE :1. Gradation as per Table 400-4 of MoRT&H. 2. Data as per 4.6 of MoRT&H Standard Data Book (First Revision). 3. Ratios of (37.5-9.5):(9.5-4.75):(4.75-0.75) is (32.5) % : (5) % : (62.5) % vvnhighways.blogspot.in
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SUB-BASE LAYER – Unbound Sub-base Layer- GRANULAR I. FUNCTIONS :- It serves THREE Functions. 1. Protect the Subgrade from over stressing. 2. Provides platform for construction traffic. 3. Serves as drainage and filter layer.
II. MATERIALS (GSB-401 of MoRT&H) :Crushed stone, Sand, Reclaimed Crushed concrete, reclaimed asphalt Pavement , Crushed slag or combinations there of
III.PROPERTIES of Granular Sub-base :1. Gradation as per Table 400-1 of MoRT&H. 2. AIV less than 40%. 3. Material passing 425 micron should have Liquid Limit not more than 25 and Plasticity index not more than 6.
IV. COMPOSITION :1. LOWER LAYER serves as SEPARATION/ FILTER Layer -- Gradings III and IV. 2. UPPER LAYER serves as Drainage Layer -- Gradings V and VI.
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BASE LAYER – Bound Sub-Base Layer – CEMENT TREATED I. FUNCTIONS :- It serves THREE Functions. 1. Protect the Subgrade from over stressing. 2. Provides platform for construction traffic. 3. Serves as drainage and filter layer.
II. MATERIALS(403 of MoRT&H) :1. Aggregates modified with Cement. III.PROPERTIES of Cement treated Sub-Base :1. Gradation as per Table 400-4 of MoRT&H. 2. Data as per 4.6 of MoRT&H Standard Data Book (First Revision). 3. Ratios of (37.5-9.5) : (9.5-4.75) : (4.75-0.75) is (55) % : (20) % : (25) %
IV. COMPOSITION :1. LOWER LAYER serves as SEPARATION/ FILTER Layer. 2. UPPER 100mm LAYER serves as Drainage Layer -bound with 2-3 % cement. vvnhighways.blogspot.in
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PAVEMENT DESIGN PROCEDURE
The FLEXIBLE PAVEMENTS can designed USING IITPAVE. Any combination of traffic and pavement layer composition can be tried using IITPAVE. The strength of materials used and the stresses from traffic are the parameters.
USING DESIGN CATALOGUES. These Guide lines provide a design Catalogue giving pavement compositions for various combination of TRAFFIC. LAYER CONFIGURATION and ASSUMED MATERIAL PROPERTIES. vvnhighways.blogspot.in
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PAVEMENT DESIGN CATALOGUES
FIVE different combinations . In cement bases for the cases 2, 3 & 4 the top 100 mm of sub-base is to be porous and act as DRAINAGE LAYER. vvnhighways.blogspot.in
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PAVEMENT DESIGN CATALOGUES -1 BITUMINOUS SURFACING with GRANULAR BASE and GRANULAR Sub-BASE.
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Bituminous composition with Granular Bases
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Bituminous composition with Granular Bases
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Bituminous composition with Granular Bases ABSTRACT- ( 400 to 850 mm) SUSURFACE LAYER – BITUMINOUS :: 50-220 mm thick. WEARING COURSE :MIX SEAL -> 20 mm thick up to 2 msa of traffic. SDBC -> 25 mm thick up to 5 msa of traffic. BITUMINOUS CONCRETE (BC) -> 40 to 50 mm 5 to 150 msa
LAYER BELOW WEARING COURSE :DENSE BITUMINOUS MACADAM (DBM) -> 30 to 170 mm.
BITUMEN :- VG 40 grade for BC and DBM for traffic > 30 msa.
INTER LAYER. NOT NECESSARY. BASE LAYER – GRANULAR :: 225 & 250 mm thick. WET MIX MACADAM or (WBM, CRUAHER RUN MACADAM, RECLAIME CONCRETE) 225 mm thick up to 2 msa of traffic. 250 mm thick 2 to 150 msa of traffic.
SUB-BASE LAYER – GRANULAR:: 100-380 mm thick. GSB as per MoRTH. 100 to 380 mm 2 to 150 msa of traffic.
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PAVEMENT DESIGN CATALOGUES -2 BITUMINOUS PAVEMENT with CEMENT TREATED BASE and CEMENT TREARED SUB-BASE.
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Bituminous composition with Cement treated base & sub-base
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Bituminous composition with Cement treated base & sub-base
ABSTRACT- ( 410 to 590 mm) SUSURFACE LAYER – BITUMINOUS :: 30-100 mm thick. WEARING COURSE :SDBC -> 30 to 40 mm thick up to 5 msa of traffic. BITUMINOUS CONCRETE (BC) -> 40 to 50 mm 5 to 150 msa
LAYER BELOW WEARING COURSE :DENSE BITUMINOUS MACADAM (DBM) -> 50 mm for traffic 50 -150 msa.
BITUMEN :- VG 40 grade for BC and DBM for traffic > 30 msa.
INTER LAYER -- AGGREGATE :: 100 mm thick. BASE LAYER – CEMENTED :: 30- 140 mm thick. AGGREGATE STABLISED WITH CEMENT. Minimum Strength 4.5 MPa @ 7days and 7.0 MPa @ 28 days.
SUB-BASE LAYER – CEMENTED :: 250 mm. AGGREGATE /SOIL modified with stabilizers. DRAINAGE LAYER -> Top 100 mm Coarse Aggregate with 2-3% Cement. FILTER LAYER -> Bottom 150 mm Stabilized Aggregate/ Soil.
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PAVEMENT DESIGN CATALOGUES -3 BITUMINOUS SURFACING with CEMENT TREATED BASE and CEMENT TREARED SUB-BASE with SAMI.
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Bituminous Surfacing with cement treated base and cement treated sub-base with SAMI.
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SAMI-Stress Absorbing Membrane Interlayer SAMI- It is a layer which is laid on cracked pavement surface before laying Bituminous Surfacings, i.e., sandwiched layer between cracked layer and Bituminous layer. MATERIALS :: Modified Binder 8-10 kg per 10 sqm… Aggregate Chips of 5.6 mm size 0.100 cum per 10 sqm.
METHODOLOGY :: Modified Binder heated to 160-1700C and sprayed on prepared Base layer using pressure sprayer. Aggregate Chips 10 mm size are spread within 2 minutes using mechanical spreader. Rolling carried out within 5-10 minutes using pneumatic/ steel tire self propelled roller and continued till all cover aggregate particles are firmly embedded in Bituminous material. Sweeping is carried out to remove all excess chippings. MEASUREMENTS :: Finished work in square meters. vvnhighways.blogspot.in
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Bituminous Surfacing with cement treated base and cement treated sub-base with SAMI.
ABSTRACT- ( 360 to 530 mm) SUSURFACE LAYER – BITUMINOUS :: 30-100 mm thick. WEARING COURSE :SDBC -> 30 mm thick up to 5 msa of traffic. BITUMINOUS CONCRETE (BC) -> 40 to 50 mm 5 to 150 msa
LAYER BELOW WEARING COURSE :DENSE BITUMINOUS MACADAM (DBM)
-> 50 mm for traffic 30 -150 msa
BITUMEN :- VG 40 grade for BC and DBM for traffic > 30 msa.
INTER LAYER -- SAMI (Stress Absorbing Membrane Interlayer). BASE LAYER – CEMENTED :: 80- 180 mm thick. AGGREGATE STABILIZED WITH CEMENT. Minimum Strength 4.5 MPa @ 7days and 7.0 MPa @ 28 days.
SUB-BASE LAYER – CEMENTED :: 250 mm. AGGREGATE /SOIL modified with stabilizers. DRAINAGE LAYER -> Top 100 mm Coarse Aggregate with 2-3% Cement. FILTER LAYER -> Bottom 150 mm Stabilized Aggregate/ Soil.
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PAVEMENT DESIGN CATALOGUES -4 BITUMINOUS SURFACINGS with BITUMEN TREATED RAP/ AGGREGATE OVER CEMENT TREATED SUB-BASE.
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Bituminous Surfacing with Bitumen treated RAP /AGGREGATE over cement treated sub-base.
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RAP : RECYCLED ASPHALT PAVEMENT RAP : RECYCLED ASPHALT PAVEMENT :: Asphalt pavement reclaiming/recycling involves reusing the in-place pavement material to rehabilitate and/or strengthen the asphalt pavement structure. The recycling process involves removing the asphalt pavement materials of the pavement structure, usually by cold milling. After adding new materials, reheating the recycled mixture and placing it with the same methods as used for conventional virgin asphalt concrete. Minimal adaptation of existing pavement construction equipment or new equipment purchases are required for hot-mix recycling. The proportions of old material to new material in the blending process will be governed by the material properties of the old asphalt concrete and the specification requirements for the recycled mix. vvnhighways.blogspot.in
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Bituminous Surfacing with Bitumen treated RAP /AGGREGATE over cement treated sub-base.
ABSTRACT- ( 255 to 600 mm) SUSURFACE LAYER – BITUMINOUS :: 25 to100 mm thick. WEARING COURSE :SDBC -> 25 mm thick up to 10 msa of traffic. BITUMINOUS CONCRETE (BC) -> 40 to 50 mm 10 to 150 msa
LAYER BELOW WEARING COURSE :DENSE BITUMINOUS MACADAM (DBM) -> 50 mm for traffic 50 -150 msa.
BITUMEN :- VG 40 grade for BC and DBM for traffic > 30 msa.
INTER LAYER -- NOT NECESSARY. BASE LAYER – Bitumen treated RAP /AGGREGATE :: 30- 250 mm thick. RAP- Reclaimed Asphalt Pavement.
SUB-BASE LAYER – CEMENTED :: 200 to 250 mm. AGGREGATE /SOIL modified with stabilizers. DRAINAGE LAYER -> Top 100 mm Coarse Aggregate with 2-3% Cement. FILTER LAYER -> Bottom 100-150 mm Stabilized Aggregate/ Soil.
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PAVEMENT DESIGN CATALOGUES -5 BITUMINOUS SURFACINGS with CEMENT TREATED BASE and GRANULAR SUB-BASE with AGGREGATE INTERLAYER.
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Bituminous composition with cement treated base and GRANULAR sub-base.
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BITUMINOUS SURFACINGS with CEMENT TREATED BASE and GRANULAR SUB-BASE with AGGREGATE INTERLAYER.
ABSTRACT- ( 520 to 680 mm) SUSURFACE LAYER – BITUMINOUS :: 30 to100 mm thick. WEARING COURSE :SDBC -> 30 mm thick up to 5 msa of traffic. BITUMINOUS CONCRETE (BC) -> 40 to 50 mm 5 to 150 msa
LAYER BELOW WEARING COURSE :DENSE BITUMINOUS MACADAM (DBM) -> 50 mm for traffic 50 -150 msa.
BITUMEN :- VG 30 up to 30 msa & VG40 for traffic > 30 msa.
INTER LAYER -- 100 mm thick (of Wet Mix Macadam) . BASE LAYER – CEMENTED :: 140- 230 mm thick. AGGREGATE STABLISED WITH CEMENT. Minimum Strength 4.5 MPa @ 7days and 7.0 MPa @ 28 days.
SUB-BASE LAYER – GRANULAR :: 250 mm thick. GSB retained from existing Highway. vvnhighways.blogspot.in
USES . FOR RECONSTRUCTION OF EXISTING HIGHWAYS. G. S. B. of EXISTING HIGHWAYS is retained. 77
BITUMEN - CLASSIFICATION Based GRADATION values STRAIGHT RUN BITUMEN is classified in 3 ways. 1. PENETRATION GRADING (Adopted 1950-2006) :: Penetration of needle loaded with 100 gm for 5 seconds at temperature of 250 C. Penetration is expressed in units of 0.10 mm. 80/100 means Penetration of needle 8 to 10 mm. It is an ARBITRARY & EMPIRICAL test not SCINTIFIC. It does not involve the measurement of any fundamental engineering parameters. 250 C is an average Annual temperature which is a low service temperature.
S90 (80/100), S65 (60/70), S55 (50/60) and S35 (30/40) are 4 types penetration grades for Highways from softer to stiffer grade. Penetration graded bitumens can be more prone to rutting than viscosity graded bitumens. 2. VISCISITY GRADING :: 3. PERFORMANCE GRADING (Superpave performance Grading) :: vvnhighways.blogspot.in
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BITUMEN - CLASSIFICATION 2. VISCISITY GRADING (Adopted from 2006) :: Viscosity (degree of fluidity) denotes the fluid property of bituminous material. It is a measure of resistance to flow when a shearing stress is imposed on it. Viscosity is typically calculated from the time required for the bitumen binder to flow between two successive marks. Viscosity of bitumen is measured at 600C temp. which is a service temperature for Pavement. Viscosity also measured at 1350C and retain penetration grading system at 250C. It is expressed in units of POISES (grams per cm per second). It is a SCINTIFIC and FUNDAMENTAL test . This system had an excellent performance history . Based on Viscosity at 60OC Bitumen is Classified as VG-10, VG-20, VG-30 and VG-40 grades. VG-10 minimum Absolute viscosity 800 Poise at 600C. VG-20 minimum Absolute viscosity 1600 Poise at 600C VG-10 minimum Absolute viscosity 2400 Poise at 600C VG-10 minimum Absolute viscosity 3200 Poise at 600C vvnhighways.blogspot.in
VISCOSITY of fluids in Poise Water - 1 Blood - 10 Caster oil - 350 Honey - 3500 79
BITUMEN - CLASSIFICATION
3. PERFORMANCE GRADING (Not Adopted in INDIA) :: Aimed at addressing: Physical properties measured are directly related to field performance by engineering principles. Climatic effects from complete range of pavement service temperatures. Construction. Aging during construction and in-service. Traffic speed. Traffic volume. Site condition.
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BITUMEN, DIFFERENT GRADINGS & PROPERTIES Bitumen is a thermoplastic material, Its stiffness is dependent on its temperature. A. B. C. D.
-100, -150 :: Minimum pavement temperature. Thermal cracking. 250C :: Average annual temperature. Pavement raveling and/or Fatigue cracking. 600C :: High Service temperature, critical performance temperature. Deformation, Rutting. 1350C :: Mixing, Transportation and Compacting temperature.
1) Penetration grading addresses Bituminous property B only. 2) Viscosity grading addresses Bituminous properties B, C and D. 3) Performance grading addresses Bituminous properties all A, B, C and D. This grading also addresses real properties during service period. vvnhighways.blogspot.in
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BITUMEN GRADATION, MoRT&H GUIDE LINES
MoRT&H Guide lines in selection of appropriate grade of Bitumen based on VISCOSITY GRADE. I. VG-10 Grade may be used in place of : 80-100 penetration grade Bitumen.
II. VG-20 Grade may be considered for : Special cases only.
III. VG-30 Grade may be used in place of : 60-70 penetration grade Bitumen.
IV. VG-40 Grade may be used in place of : 30-40/ 40-50 penetration grade Bitumen.
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BITUMEN SELECTION for BITUMINOUS LAYERS
PMB :: Polymer Modified Bitumen. NRMB :: Natural Rubber Modified Bitumen. CRMB :: Crumbed Rubber Modified Bitumen.
When CVPD exceeds 2000 per Lane and Daily Mean temperature exceeds 400C VG-40 Bitumen or Modified Bitumen of Equivalent stiffness may be used for Wearing Course. vvnhighways.blogspot.in
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EQUIVALENCE OF THICKNESSES of BITUMEN MIXES
IRC:37-2012 :: Considers Elastic Modulus (E)of Bitumen for Equivalence. Pavement design Charts are prepared at 350C air Temperature. At 350C Resilient Modulus DBM for VG 10 bitumen -- 1000. DBM for VG 30 bitumen -- 1700. DBM for VG 40 bitumen -- 3000. DBM for Modified bitumen -- 1650. BM for VG 10 bitumen -- 500. BM for VG 30 bitumen -- 700.
The thickness are related . 3 E 1 H 1 = H
2
=
H
1
3 E 2 H 2 *
E E
1 2
1 / 3
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LINEAR INTERPOLATION 1 x ---x **** 1 1 y x
2 y
1 y
yyyy
− )
2 x
=
(
)
1 y 1 x
(
y
2 x
(
2 y
y2
1 x ---x
− )
1 y ---y
( + (
− )
− )
* ( x − x1)
1 x
− )
1 y
− )
(
* ( x − x1)
1 x
2 x
− )
1 x
x **** 1 1 y x
2 y
=
( + (
1 y
At any intermediate Value x , value of
yyyy
Second PAIR (x2, y2)
1 y
First PAIR (x1, y1)
− )
2 x
x
− )
2 y
x2
− )
2 x
x1
( y = y1 + (
2 y
y1
( ( y − y 1) = (
) ( = ) (
− )
PAVEMENT DESIGN EXAMPLE
Effective CBR
LDF
A& VDF
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PAVEMENT DESIGN EXAMPLE
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PAVEMENT DESIGN EXAMPLE
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PAVEMENT DESIGN EXAMPLE
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Bituminous composition with Granular Base & Granular Sub-bases
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Bituminous composition with Granular Base & Granular Sub-bases
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Bituminous composition with Cementitious Base & Granular Sub-bases
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Bituminous composition with Cementitious Base & Granular Sub-bases
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Bituminous composition with Cementitious Base & Granular Sub-bases
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Bituminous composition with Cementitious Base & Granular Sub-bases
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DISPARITIES NOTICED in IRC:37-2012
1. Page no. 8, Para 4.5.1 (II) :: 50 percent of total … As per IRC:37-2001 Page No. 13, Para 3.3.5.1 (II) it is 75 %. In this Presentation 75 % is adopted.
2. Page No. 26 to28 , Plate No. 2, 3, 4, 5, 6 & 7:: Wearing Course is given as 2O mm thickness of SDBC. SDBC Specification is discarded in MoRT&H ( 5th Revision). In MoRT&H ( 4th revision) Table 500-15 grading 2 Layer thickness is given as 25-30 mm.
3. Page No. 36 & 37 , Plate No. 17, 18, 19 &20 :: For traffic 10 msa Wearing Course is given as 25 mm thickness. In the legends of the same charts it is given as BC/SDBC ( upto 5 msa). In MoRT&H ( 5th revision) Table 500-17 of Bituminous Concrete , grading 2 Layer thickness is given as 30-40 mm. Doubt? Whether 25 mm is treated as SDBC of BC ? vvnhighways.blogspot.in
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References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
IRC : 37-2012 Guidelines for the design of Flexible Pavements ( 3rd Revision). IRC : 37-2001 Guidelines for the design of Flexible Pavements ( 2nd Revision). IRC:111-2009 Specifications for Dense Graded Mixes for Bituminous Mixes. IS:73-2013 -Indian Standard PAVING BITUMEN — SPECIFICATION (4th revision). MORT&H Specifications for Road and Bridge works ( 5th Revision). MORT&H Specifications for Road and Bridge works ( 4th Revision). MoRT&H Manual for construction and supervision of Bituminous Works. MoRT&H STANDARD DATA BOOK FOR ANALYSIS OF RATES ( 1st Revision). Principles and practices of Highway Engineering. -L.R. Kadiyali. Introduction to Transportation Engineering - Prof K Sudhakar Reddy. An Overview of the Viscosity Grading System Adopted in India for Paving Bitumen -Prof. Prithvi Singh Kandhal. Handbook of Road Technology, Fourth Edition M. G. Lay MoRT&H Circular on Viscosity grade bitumen. Some sites in Internet. MS office 2010.
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acknowledgements 1) 2) 3) 4) 5) 6) 7) 8) 9)
Sri P. Ravindar Rao, EinC (R&B) Govt. of Telangana. Sri K. Bikshapathi EinC (R&B) Govt. of Telangana. NAC :: National Academy of Construction, Hyderabad. Sri S. Jaswant Kumar, C.E.(D&P), R&B Dept.(Retired). Sri D.V. Bhavanna Rao C.E. (QC), (R&B) Dept. Retired. Sri L. Mallaiah, J.D. Research station, HYD. Sri M. Balanarsiah, E.E (R&B), Sangareddy. Master V. Sraman, Sri M. Kishan, AEE (R&B), ZAHEERABAD.
10) Sri Md. Waseem Aqthar AEE(R&B), ZAHEERAABAD.
11) Smt I. Shantisree, NAC. V. VENKATA NARAYANA Dy. Executive Engineer, vvnhighways.blogspot.in
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THANK YOU V. VENKATA NARAYANA, DEPUTY EXECUTIVE ENGINEER (R&B),
9440818440, 07799139399,
[email protected] vvnhighways.blogspot.in vvnhighways.blogspot.in
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