Max Fajardo Simplified Methods on Building Construction

Simplified Methods on

BUILDING·CONSTRUCTION

MAX 8. FA.JAAOQ JR. B. S. Architecture, National University 1961; Passed the . Boord Exam for Architects 1961; Former Deon College of Architecture and Eng in~ering, University of North Eastern Pl)ilippines; Architect, . Public ';tNorks Province of Comorines Sur; Practising Architect and Contractor; Author and pu~ Usher of S'implified Construction Estim~te_

Philippines Copyright

1983

by

MAX B. FAJARDO, JR.

All Rights Reserved Every copy of this book must bear the genuine signature of the author. Copies not having the signature will be deemed to hove emanated from on illegal source.

FOREWORD Experienced builders agree that Building Construct ion is considered os the most challenging, complicoted and articulate work in the field of construction. To discuss the subject matter embracing the whole aspect o~ b_uilding construction from the laying out up fo the lost touch of the finished work requires· several volumes. The author in this f irst volume presents the rudimentary knowledge os well os the techn ie:a/ aspect and procedur~ of building construction. The book was designed to present the technical trade in-formation in a short, concise, d irect and plain language accompanied with illustrations os o visual aid to the reader. Useful tables, conversion foetor and formulae from the English to the Metric System (Sil, various permit forms, problems and solutions were also incorporated. Hand tools, power tools and equipment including their respective uses and functions in the construction were also p re- . sented because the author considered those to be the first one a builder should be fam iliar with before any other thing in the construction. The book could be of great help to Architecture and Engineering students as well as trade school stude nts, carpenters and laymen who ·have interest in the field of construction. ·For the first.vqlume, the author wishes to express his grateful acknowledgement to the. valuable research and contributions. of PepinN . Fajardo, and also to the constructive sugge~t ions of Supervisor Jhonny Blonquera who first read the preliminary . manuscript. The author likewise expresses his indebtedness and gratitude to the persons here unnamed wro in one way or another hove contributed to the full realization of this book.

M. B. F.

}•

TAILE OF CONTENTS CHAPTER I 1·1 1-2

1-3 1-4

l -5 1-6..

1-7

l-8 1-9

1-lO I -ll 1-12 1- 13 1- 14 1- 15

Mea suring i ools . . . .•.. •. . . .. . .. .. •. . • ... .. Marking Tools • .• . . •... .. . •.• . ..• . . .. . .. . Testing and Guiding Tools • ... .••. .. •..• •.• • Fastening Too I5. ••• • •.. •• • • •.. • • • • • •• ••• •• • Rough Foc:ing Tools . . .. . . ....• . ..... . .... Toothed Cutting Tool!> . . ... .. . . .• .. . . .•• .. .. Sharp-Edged C~tt i ng Tools .. . . . . .. . . . .... . Smooth Facing Tools . . ...... . : . ... .. ..... . . Boring o r Drill ing Too ls ... .. . . .. .... . . .. . . . Holding Tools ... .•. . . .. . . . . ... . . . . .. . .. .. Sharpening Tools . . . . . .. .. ... . . . . . .. ..... . Work Bench .. .. .. . .. .. ...•• •. .. . ...•... Roughing Up Tools .. . . .. .. . . .. : . . . . ... . . . Surface Finishing Toofs .. . .. . .. \ .... . ... . . . M iscel laneous Ma son ry Tools . . . . . . ...... .

CHAPTER 2 2-1 2-2 2-3

2-4 2-5

4!-6 2-7 2~8

2-9

TOOLS

2 5

6 12

·13 14 19

22 26

29 31

32 33

35 37

WO 0 0

Introduction ... .... .. ... ......... ,,. .. ... ~· .,,. ,. :.... . . Definition of Terms .... . .- .,)••··-"' . . ... . . ..... .,.•,..._. Classification of Wood .i . . .r • • • ' ·' . . , •• • • • , ,.,..,. _ Preparation of Wood . . . .. .. ·" . . ..• . . . ... .. , ,__, , Defects in Wood .• .... ., ••. , ..• , ... .. .... ... .. , . Of~ Seasoning of Wood . .. .. •.... .... • .. . .... . .,,... ~ Causes of Deca y and Methods of..F!JeServotrtm. --:':'J Measuring of Wood . •.. .. , . ... . ... .... ..... . ,. . Eng lish to Metric Measure o.f'· ~ --~. ,_.. ._. • .;.• . .

CHAPTER 3

Page

42 42 43

44 45 46 47 49 51

LA.YOUT AND EXCAVATIONS .

3-l

·53

3-2 3-3 3-4

57

De finit ion . . . •... . ....• • ... •. . •... .. . . . .. . Lay'out Method s c;m d Procedures .. .. ... ... .. . M inor ExcCtvation ... . ,. • ... ..... •. . . .. .. . . .. Major Exca va tion .. . ... . . . . . . . . . : ......... . J ... Sheeting and Bracing Sha llow Excavat ion .. . 3-6 Sheeting and Bracing ·of Deep Excavation . • . Sheet Piles ..... . ..... . ..... .. ... . ..... . . 3-7 3-8 Exca va t ion in So nd .. . .... , . . ......... . . .. . 3-9. Excavation in Clay · . . . . ... . . . •.. . . .. ... ... 3-10 Filling · ... . . .. .. . .. .. . . . . .. • ; ... . . . . ..... .

s

53 59 61

63 65

67

68 69

CHAPTER 4

C0 N C R ET E

Concrete ........ , ............... , , ...... ~ .. Cement ........................... ~ ...... . 4-3 Aggregate ...............•................ Water ......................... , . ~ ........ . 4-4 4-5 Types of Concrete ond Their Weight ....•..•.. 4-6 Mixing of Concrete .............•.......... 4-7 Segregation ............................•.. 4-8 Requirement for Good Quality Concrete ..... . Curing ............................. , . , .. . 4-9 4-10 Admixture .............................. . 4-11 Concrete Proportion and Water Cement Ratio .. 4-12 Tests ................. ·...................... . 4-1

4-2

CHAPTER

5

Steel Reinforcement .........••......•... , . Steel Bars ·from English to Metric Measure .... Prestressed Steel •..•••••.•.•••........•..•• 5-3 Welded Wire Fabric ..................••... 5-4 5-5 Identification of Steet Bars ................. . 5-6 Bar Cut Off and Bend ·Points ..•............. Bar Splicing ................•....•... ; ... . 5-7 Bar Spacing ........•....... .' ............. . 5-8 Concrete Protection for Reinforcement ....... . 5-9 5-10 Bundle of Bars ....• ; ..•.•.....•............ 5- J 1 Control of Crocks ......................... . S-12 Metal Reinforcement Specifications . . . . . .. 5-2

6-l 6-2

6·3 6-4 6-5 6-6 6-7 6~8

6-9 6-10

6-ll

6·12 6·13

72 72 73 76 76 77

78 78 82

METAL REINFORCEMENT

5-1

CHAPTER 6

7J 71 71

86 87 90 91 91 93 94 94 95 97

98

98

F 0 U N D AT I 0 N

Brief History ••••••••••••••••••. Wall Footing ...•........•..•..•...... , ... . Isolated or Independent Footing ......•..... Combined Footing ..••..•....•............. Continuous Footing ..•.......•...•........• Raft or Mat Footing ......•........•....... Piile Foundation ........•..••............•. Piles •••••••...••..••.•••...•.• ............. . The Important Functions or Uses of Pile~ ... . Quality and Durability of Piles .•..... , ..... . Timber Piles .....................•....... Deterioration of Wood Piles .............•.. Protection of Timber Piles .................. · !

......... .

100 102

102 106 107 107. 109 109 110

112 113 114 114

6-14 6-15 6-16 6-17 6-18 6-19 6-20 6-21 6-22 6-23 6-24 6-25

Pile Dr.iving .................. .. .... .... . Con.rete and Pipe Piles ...... ·.... ........... . Precast Concrete Piles ............ -. -.- ... . Deterioration of Concrete Piles ....·.... ..... . Metal' Pile ....••.... - .. ,. .. : . •.... . . . . . ... Driving Equipment· •..........••••... : . ... . Pile Spacing .............. ........ ........ . Driving of Piles Through on Obstruction ... . Causes of Pile Deflection in Driving Settlement of Foundation ............. . .. . . Failure of Pile Foundation ................. . Grillage Footing •.•............. ·.......... .

CHAPTER 7 7-1 7-2 7-3 7-4 7-5 7-6 7J7 7-8 7-9

115 118 119 119 120 120 124 124 125 125 126 l27

SOIL TEST

Auger Boring . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wosh Boring . . . . . . . • . . . . . . . . . • . . . . . . . . . . . Hollow Stem Auger Boring . . . . . . . . . . . . . . . . . Rotary Drilling ........•....•..••... : . . ; . . Percussion Drilling • . . . . . . . • . . . . . . . . . . . . . . Penetrometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dutch Cone Penetration . . . . . . . . . . . . . . . . . . . Vone Shear Test ..... :. . . . . . . . . . . . . . . . . . . Standard Load Test . . . . . . . . . . . . . . . . . . . . . . .

f 28

128 129 129 130 130 130 131 182

CHAPTER 8 POST AND COLUMN 8-1 8-2 8-3 8-4 8-5 8-6 8-7 8'-8

Definition . . . . . • . . . . . . . . . . • . . • . . . . . . . . . . . Wooden Post . . . . • • • . • . . . • • • • • . . • . . • . . . • • . . Rein'forced Concrete Column . . . . . . . . . . . . . . . T ied Colu mn . . . . • • . . . . . . . . . . . . . . . . . . . . . Spiral Column . . . • . . . . . . . • . . . . . . . . . . . . . . . Composite ·cotumn . • . . . ... • . . • . . . . . . . . . . . . Combined .Column . . . . . . . . . . . . . . . . . . . . . . . . Lally Column .. . . .. .. .. .. .. . .. .. .. . .. . . .

CHAPTER· 9 9-1 9-2 9-3

9-4 9-5 9-6 9-7

13'-4 134 136

137 149 159 160 l 61

PLATFORM- FLOOR STRUCTURE

Wood Floor System • . . . . . . . . . . • . . . . • . . • . . . Beam ...••. .. ....... ..•• ..•••..... .. : . . . Relation Between the Materials and Structure . . Behavior of Beam Under the Influence of Load . Reinforcement of Concrete Beam . . . . . . . . • . The Compression and Tension m a Beam . . • . Spacing of Reinforcing Bars in Seam ... ·~ • . • .

162 165 16.7

l69 170 171 173

9-8 9-9

9-10 9-11 9-12 9-13 9- 14 9-15

9-16 9-17

Splicing Hooks and Bends .. .. .. .•• .- •••• •.. 174 175 Steel Bors Cut Off 'o nd -Bend Point ......• • .. 176 Beams Reinforced- for Compression •. ••• .• .. 177 Web Reinforcement ....... . .• . ...... .... . 177 Tor&ion in Reinforced Concrete Member •.•• . • 178 T-Beam Design & limitation , • • . ••.•• . ... . . 178 Other Causes of Beam Failure ...•.•....•.. ~einfarced Concrete Slob .. ....•.•••••.••• . . 179 Ribbed Flood Slab . ...... ............... ..· 186 189 The AC I on Concrete Joist Floor Construction .

CHAPTER 10 · STEEL FRAMING 10-1 10-2

Introduction . . .. . . . ..... . . . ..•••••.... . .. Structural Shapes . . ....•. • .... . • . .•• .•. ... 10-3 Structural Steel ... . ....... . .. . .. . ........ . 10-4 High Strength Steel ....... .. . ..•.... . .. .. . Rivets and Bolts . . . . . . . . . . . .••.•.... . .. .. l0-5 l0-6 Riveting Procedures . . ... ... . ....•.••..... . 10-7 Conditions for Punching and Drilling •.. : ... . Bolts ~ . ...... .. . ...... ..... ,. .. .•• _ • : ... ... . 10-8 Connect ion of Structu ral Members .... . . ... . 10~ 9 10-10 Plate Girders . .. .. ... . ..... . .. ... ..... . .. . 10-1 1 Web Plates and· Intermediate Stiffeners ..... . 10- 12 Roof Trusses ........ . ............... . . .. . 10- 13. Welded Connections .•...... .. .•.... .. .... . CHAPTER 1.1 11-1 11 ..2 11 - 3 11 -4 11-5 11-6 1 1-7 11-8

195 195 196 196

197 200 200 206 207 211

212

TIMBER ROOF FRAMING

Introduction . • . . . . . . . . • • . . . . • • . • • • • . . • . . Types of Roof .. .. . .. .. . .. .. • . . • • .. .. .. . .. Types of Roof Frame . . ....• ... , . . • . . . . . . . . . T imber Framing Fasteners . . . . • . . . . . . . . . . . . . lntf!rmediate Joints . . . . . . . . . . . . . . . . . . . . . . . . End Joints ·• . . . • . . . . • . . . . . . . . . . . . . . . . . . . . . Splicing . . • . . . . . . . . . . . • . . . . • . . . • . . . . . . . . . Glued Laminated Lumber . . . . . . . . • • . . . . . . . .

CHAPTER 12 'ROOF AND 12- l 12-2 12-3 t 2-4 12-5

190 191

215 216 220 225 228 231 233 235

ROOFING MATERIALS

Roofing Materials . . . . . . .. .. . . • .. .. .. • .. .. Galvanized iron Sheets ... . . . - .............. Corrugated G.J. Roofing Fasteners·......... . Advantages and Disadvantages of G. I. Rivets . . Advantages and Oisadvcntagess of G. I. Nails . :

242 243 246 247 247

Technical Specifications .•. . .•.....•....• . .. 248 Plain G.l. Sheet ...••...................... 249 252 12-8 . Flat, Standing Seom and Botten_Roofing ..... . 12-9 Slope of RooF • . . ... . . . . . . . . . . . . . . . . . . .... . . . 252 255 12-lO Cloy Tile Roofing ... . .... ... ....... .. ... . . 256 12-1 1 Asbestos ond Color. Bond Roofing . .. .... .... .

12-6

12-7

CHAPTER 13-1

13-2 13-3 13-4 13-5 13-6

13-7

13

STAIRS

Introduction ...•.•••.............•...... · . Definitions . . . . • . . • • • . . . . . . . . . . . . . . . . . . . . Laying Out of Stairs ...................... · . laying Out the Stringer . , . . . . . . . . . . . . . . . . . . Type of Stringers . . . . . . . . . . . . • . . . . . . . . . . . . Handrail and Balusters . .. .. .. . . .. . . .. .. . .. Re inforced Concrete Sta irways . . . . . . . . . . . . .

259 259 263

263 265

266 266

CHAPTER 14

PRECAST AND PRESTRESSED CONSTRUCTION ·Introduction . . . . . . . . . . . . . . . • . . . . . . . . . . . . . Types of Precast Structure ....... . ......... . Roof and Floor Members ....... ..... ·. . . .. •.. 14-3 14-4 Precast Beams •.••••••••• • .•.. .. .•. .. .•.• 14-5 Precast Column ................... .. .•... 14-6 Prestressed Concrele .................... . l4-7 Prestressing of Concrete ........ ... ... .. ... . 14-8 Concrete for Prestressing ... ............. . . 14-9 Shope of Prestressed Structure ... . ......... . 14-10 Metal Rein:orcement .. .... .............. . 14-11 Grout for Bonded Tendons ...... .. ... ..... . 14-12 Measurement of ~restressing Force .. .. . . ... . 14-13 Post Tensioning Anchorage . .... . .......... . 14-1

J4~2

CHAPTER 15 15- J

1-5-2

~5-3

15-4 15·5 15-6 15-7

269 269 270 271

272 272 273 275

275 , 280 282

283 283

FORM, SCAFFOLDING AND STAGING

Form . . . • • . . • . . • . . • . . . . . . . . . . . . . . . ... . . • . . Construction ,f forms ...•.......... ,' ,.:. . . Erection ond Securing of Forms . . . . . . . . . . . . Wall Forms ...•••..................... ·. . . . Greasing of Forms . . • • . . . . . . . • . . . . . . . . . . . . Comparative Analysis Between tke T&G ond Plywood as Form . . • . . . • • • • • . • . . . . • . . . . . . Scaffolding and Staging .. • .. • .. .. . . . . . .. . ..

284 285 287 288 288 289 290

15-8

Stag ing for Reinforced Concrete Beam and Floor Slob • . . . • • . • • . . . . . • . . . . . . . . . . . . . . . . Conduits and Pipes Embedded in Concrete

15-9

293 294

CHAPTER 16

HOISTiNG EQUIPMENT and POWER TOOLS 16- 1 16-2 16-3 16-4 16-5 16-6 16-7 16-8 16-9 16- 10 16-1 1 16-12 16- 13 16- 1-4 16-15 16-16 16-17

Hoist • . . . • • . . . . • . . . . . . . • • . . . • . . . . . . • . . . . • Definitions . . • . • . . . . . . . . • . . . . • • . . . • • . . . . . . Knotting and H 1tching . . .. .. . . .. . . . . . . .. Pu lleys .....•. . ..... . ...•....... . .... .. .. Circu lar Sow . . ........... . ... , . . . . . . . . . . . . Radial A rm Sow . . . • . • . . • • . . . . . . . . . . . . . . . . . Portable Electric Sow . . . . . . . . . . . . . . . . . . . . . . . Portable Electric Drill . . . . . . . . . . . . . . . . . . . . . . Drill Press ·. . • . . . . . . • . . • . . . . . • . • . . • • . . . . . . Portable Electric Sabe r Saw . . . . . . . . . . . . . . . . Band Saw • • • • • . • . • • • • • . . . • . • . • . . . . • • . . . • Single Surface Planer . . . . . . . . . . . . . . . . . . . . . Portable Sanders . . . . . . . . . . . . . . . . . . . . . . . . . . Porta ble ·Hand Router . . . . . • . . . . . . • . . . . . . . . . Wood Lathe •. ..••..•• . , • • . . . . .. . . . . . . . . . . . Truck Mounted Crane . •..• • ........ ~ , . . , . . . Tpwer Crone . . • . . . • . . • • • • . . • . . . . . . . . . . . . .

APPENDICES

... .•... . .....•.•...... , . . . . . . . . . .

297 297 298 304 · 306 31 0 311 3 11 31 2 3 13 3 14 31 7 317 318 319 320 321 322

CHAPTER

1

TOOLS INTRODUCTION Tools had been regarded as a partner of man·s quest for progress and survival from the early stone age down to the present generation. The mechanical advantages, accuracy, speed and efficiency derived from the use of the right tools and equ ipment, has prompted man to continuously search for the refinement of old tools aside from the invention and introduction of new ones that would provide greater efficiency and refinement of work. Comparatively, it could be seen from the structures and works , of past builders, the quality. refinement of texture and the time involved in their construction to be far behind the wor ks of the present generation. These could be mainly attributed to the kind of tools and or power tools that are being used by the present contemporary builders Experienced builder agrees, that the efficiency of the work in building construction could be augmented by 25 percent or more with the use of the right kind of tools aside from the improved quality of the work performed. By hiring an experienced worker who has a complete set of tools however high his demand for pay is more advantageous and cheaper than hiring a beginner with a lower rate but without the . necessary tools for a particular job. The former although demanding a higher pay can accomplish wor~ with better qu-a lity in a 5hort time than the latter whose work r isks repair and delay not to mention the extra cost involved. The efficiency and quality of the work particularly in building construction depends upon three factors: 1. Avai labi I ity and sufficiency of materials. 2. Experience and skill of the workers in their respective field. 3. Complete set of too ls and equipment of good quality and standard make. The different kinds of construction tools may be classified according to the different kinds of trade involved:

1. Carpentry Tools 2. Masonry Tools 3. Tinsmithing Tools

4. Painters Tools ·

5. Plumbing Tools 6. Electrical Tools

A- CARPENTRY TOOLS Carpentry tools are classified according to their functions:

1. · 2. 3. 4. 5. 6.

Measuring Tools Marking Tools Testing and Guiding Tools Fastening Tools Rough Facing Tools Toothed Cutting Tools

7. 8. 9. 10.

Sharp-edged Cutting Tools Smooth Facing Tools Boring or Drilling Tools Holding Tools 11. Sharpening Tools 12. Work Bench

1- 1 MEASURING TOOLS The early developed measuring tools used in constructions were of various types provided with English-measure graduated scale into 8th. and 16th of an inch. The forerunner in making · these kinds of warranted tools are the Stanley and the Lufkins Rule Co. The increasing popularity and worldwide acceptance of the Metric measure has prompted these companies and others to adopt and incorporate the meter and centimeter rules in all the measuring tools that they are manufacturing. The recent measuring tools appear to contain the inches on one edge and the centimeters on the opposite side of either the zig-zag or push· pull tape. · Consequently, the worldwide adoption of the Metric System otherwise known as the System International (SI). manufacturers of all kinds of tools has to change the scale and graduation ot measuring tools from English to Metric measure. However, although the Engl·ish measuring tools are already obsolete, they are still presented in this topic for historical background. How the present tools developed the correlat ion between the English and the Metr ic measure, their equ ivalent values, how they served the past generation and how they used the instrumen-ts which could be of help to the educational background and advancement of the present crop of builders. The different kind,s of measuring tools that are being used in building construction otherw ise known as "Rules" are; 2

•

1. The two foot four folding rule 2. The Extension Rule 3. Zig-zag Rule

4. Push-Pull tape rule 5. Slide Caliper rule 6. Marking Gauges

The two foot four folding rule - is generally used in measuring short distances. It is usually made up of four folds connected by three hinges spaced at 6 inc;hes or 15 em apart wh ich could be ' folded-up.

Figure l-1

a~

Extention Rule - Is used for measuring inside distances such doors, w indows, cabinets etc.

Figure 1- 2

Zig-zag rule - Is ava ilabe in (4 ft.) 1.20m and (6 ft.) 1.80 m commonly used by carpenters fo r ro ugh layout. There are three types of joints available : 1. Concealed 2. Riveted 3. Springless

Push-Pull Tape rule - Is used to measure long distances; available from 1.00 m to 50 meters tong.

tio-zoo rule

Figure 1-3

Slide Caliper rule

Is used to measure outside diameter of

cylindrical objects.

SLIDE CALIPER IIULE

Figure 1-4

Marking Gauges- Is used to make lines parallel to the edges.

Figure 1 - 5 4

The two foot four folding ru le cou ld be used as a protractor using the values on table 1-1.

TABLE 1-1 ANGLES AND OPENINGS OiL Ang. Dis. Ang. Dis. in. 0 in. 0 in.

Ano, Dis. An g.

.21 3.34 .42 2 3.55 .63 3 3.75 .84 4 3.96 1.05 5 4.17 1.26 6 4.37 1.47 7 4.58 1.67 8 4.78 1.88 9 4.99 2.09 10 5.19 2.30 11 5.40 2.51 12 5.60 2.72 13 5.81 2.92 14 6.01 3.13 15 6.21

31 32 33

,

.

16 17 18 19 20 21 22 23

24 25 26 27 28 29 30

6.41 6.62 6.82 7.02 7.22 7.42 7.61 7.81 8.01 8.20 8.40 8.60 8.80 8.99 9.18

0

34

35 36 37 38

39 40 41 42 43 44 45

in.

0

9.38 9.57 9.76 9.95 10.14 10.33 10.52 10.71 10.90 11.08 11.27 11.45 11.64 11.82 12.00

46 47 48

49 50 51 52 53 54 55 56 57 58 59

60

Dis. in

Ang.

12.18 12.36 12.54 12.72 12.90 13.07 13.25 13.42 13.59 13.77 13.94 14.1 1 14.28 14.44 14.61

61 62 63 64 65

0

66 67 68

69 70 71 72 73 74 75

Dis. in. 14.78 14.94 15.11 15.27 15.43 15.59 15.75 15.90 16.06 16.21 16.37 16.52' 16.67 16.82 16.97

Ang. 0

76 77

76 79 80 81 82 83 84 85 86 87 88 89 90

1-2 MARKING TOOLS Marking tools are classified according to the kind of work it is to perform: 1. Chalk or charcoal line- is used for marking a very rough work. 2. Round pencil lead- used for mark ing rough work . 3. Scratch awl - is used in mark ing a sem i-rough work. 4. Scriber - is used in marking fine work. It is hardened steel with a sharp point designed to mark fine line. 5. Compass- is used to inscribe arcs or circle. 6. Divider - is used in dividing distances into equal parts' · particularly an arc or circumference.

5

SCRA"fCH AWL

r~--s-c_··-·-~~·· CHALK OR CHARCOAL LINE

COMPASS

Figure 1 -6

1-3 TESTING AND GUIDING TOOLS Good carpentry work demands accur~cy in measurement and a well fitted joint or parts together. This could be done with the various guiding tools for a precise and quality work. The different kinds of testing and

guiding tools are:

1. Level- is used for both guiding and testing the work to a vertical or ht>rizontal position. 2. Plastic Hose with water - is the best and accurate tool for guiding the work in establishing a horizontal level.

Figure.. 1-7 3. Plumb Bob - is used to check or obtain a vertical line. The word plumb means perpendicular to a horizontal plane.

6.

PL.UM8 808

Figure 1·8

4. Miter Box - is a device used as a guide of the hand saw in cutting object to form a miter joint.

Figure 1·9 5. Miter shooting board - is a plai n board with two 45° guide fastened on top of the upper board. This device is used for designing patterns, cabinets. etc.

'

Figure 1-10 · 7

6. Sliding r~bevel - is like a try square with a slidina and adjustable blade that could be set to any angle other than 90

SLIDING T- BEVEL

Figure 1·11

. ·TABLE 1·2 TABLE OF ANGLES Polygon No. of Sides

3

5 6 7 8 9

10

Angle

Tongue

Degrees

ln.

30 54 60 64.3 67.5 70 72

12

12 12 12 12 12 12

Blade em.

30.5 30.5 30.5 30.5 30.5 30.5 30.5

ln.

20718

8 25/32 6 15/16

5 25/32 4 31/32 43/8 3718

em.

53.0 22.3 17.6 14.6 12.6 11.1 9.8

Table 1 - 2 is useful in laying out the included angles of a given polygon.

7. Angle Divider- is a double bevel used to divide an angle a complicated work. This tool could divide an angle in one

8

/ /,.

...

[~

/

'

L-_J

SQUARE

COMBINED TRY AND ANGLE OlVlOER

MITER SQUARE

Figure 1-12

8. Square - is called a "Trying Square" . Square is a· right angle standard at 90 degrees us.ed in marking or testing work. The different types of square are: Try Square - is a square with blades that ranges from (3" to 15") 7.6 to 38 em. b) Miter Square - is a square w it h blades permanently set .

a)

at 45 degrees. c) Combined Try and Miter Square .- is a combination of 4 5 and 90 degrees in one set. d) Combination Square ..:.. is similar to a try square only that the head can be made to slide and clamp at any desired place of the blade and is also provided w ith a miter and a level gu ide. 9

e)

Framing or Steel Square - so called as it is used effectively on framing work.

FRAMING

OR

STEEL SQUARE

Figure l -13 Parts of a fram ing square:

Body- the longer and wider part Tongue- the shorter and the narrower part Face - the side visible when the square is held by the tongue in the right hand, the body pointing to the left. Back - the side ~isible when the square is held by the tongue with the left hand, the body pointing to the r ight. 10

. ,._ u:n HAND

TO NGUE.

Figure 1-14

TAf?LE 1-3 TABLE OF ANGLE FORM BY THE SQUARE (inches)

Angles: Tongue: Body:

2 3 4 5 6 7 8

9 10 11 12 13 14 15

.35 .70 1.05

1.40 1.74 2.09 2.44 2.78 3.13 3.47 3.82 4.16 4.50 4.84 5.18

20.00 19.99 19.97 19.95 19.92 19.89 19.85 19.81 19.75 19.70 19.63 19.56 19.49 19.41 19.32

Angle: Tongue: Body: Angle: Tongue:

16 17 18 19 20 21 22 23 24 25 26 27 28 29

30

5.51 5.85 6.18 6.51 6.84 7 .17 7 .49 7.80 8.13 8.45 8.77 9.08 9.39 9.70 10.00

19.23 19.13 19.02 18.91 18.79 18.69 18.54 18.40 18.27 18.13 17.98 17.82 17.66 17.49 17.32

31 32 33 34 35 36 37 38 39 40 41

42 43 44 45

10.28 10.60 10.89 11 .18 11.47 11.76 12.04 12.31 12.59 12.81 13.12 13.38 13.64 13.89 14.14

Body:

17.14 16.96 16.77

16.58 16.38 16.18 14.98 15.76 15.54 15.32 15.09 1l

"Y

Dr,..,, • M Bof Clomp

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1-- - - - ·l

'- - · -_I

ol EltlCTION OF WOOO POST

bl CORRECTING TNE 8E ND

POST

Figure 8-1 TABLE 8- 1 DIMENSION OF WOODEN POSTS OR SUPORTALES Maximum Types of Building Height of 1st Floor

1 storey shed 1 storey shed 1 storey shed 1 storey house or chalet 2 storey house or 2 storey house 2 storey house 2 storey house

l.OOm 3~00m

4.50m 5.00m

Maximum Maximum Required Maximum Height Spacing Finished Size of Total (m) of Post (m) Suportales

4.00 3.00 5.00

3.50 4.00 4.00

10 X lOcm · lOx lOcm 12.5 x 12.5 em

5.50 6.00 7.00 8.00 .9.00

3.60 3.00 4.00 4.50 4.50

12.5 x 12.5 em 12.5 x 12.5 em 12.0 x 15.0 em 17.5 x 17.5 em 20.0 x 20.0 em '11i:

Logs or tree trunk supportales may be utilized as post in its indigenous traditional type of construction, provided, that they are of the sizes and spacing capable to sustain vertical loading equivalent to the loading capacity of the posts and spacing as provided for on Table 8-1.

COMMENTS: Bent post could be corrected in the process of construction, but no att6mpt should be made to correct the bent unless proper bracing and adequate support be made first, otherwise, the foundation pedestal might break-up during the operation. The usual failure of this nature is the crushing of the pedestal brought about by the twisting of the wrought iron post strap. · At present, the trend is to avoid the use of wooden post in building construction under the following considerations: 1. Reinforced concrete column appears to be cheaper and durable.than the wood post. 2. Commercial lumber nowadays are taken from young trees thereby producing inferior quality of lumber. 3. Hardwood is scarce and could hardly be found in big lumber or sawmills. · 4. The cracks between the wooden post and the concrete wall is inevitable aside from its prominence on the wall · finished. 5. Wooden post is susceptible to decay brought about by moisture insect, worms, termites and the like.

8- 3 REINFORCED CONCRETE COLUMN Reinforced concrete is at preseRt the most popular and widely used materials for column of buildings instead of wooden post regardless of its size or height. Reinforced concrete columns are classified as: 1. Short Column = When the unsupported height is not greater than ten times the shortest lateral dimension of the cross sect ion. 2. long Column = When the unsupported height is more than ten times the shortest lateral dimension of the cross section. 136

Columns are classified according to the types of reinforcement used: 1. 2. 3. 4. 5.

Tied Column Spiral Column Composite Column Combined Column Lally Column

!--Lateral t1es

Tied Column

Spiral Column

Composite Column Combined Column

Figure 8 ·.2

8- 4 TIED COLUMN T.ied column· has reinforcement consisting of vertical or longitudinal bars held in position by lateral reinforcement called lateral ties. The vertical. reinforcement shall consist of at least 4 bars with a manimum diameter of No.5 or 16 mm steel bars. Lateral ties= The ACI Code so provides: "All non-prestressed bars for tied column shall be enclosed by lateral ties of at least No. 3 in size for lon9.itudinal bars No. 10 or smaller and at least No. 4 in size for No. 11, 14 and 18 and bundled longitudinal bars. The spacing of the ties shall not exceed 16 longitudinal bar diameter, 48 tie bar diameter or the least dimension of the column". The Code is specific that 13/8") or 10 mm diameter steel bar shall be used as lateral ties for a column reinforced with 32 mm or smaller longitudinal bars. Likewise, 12 mm steel bar shall be used as lateral ties for column with longitudinal reinforc'3ment having a diameter from 36 to 57 mm including those longitudinal bundled bars. 137·

The spacing of the lateral ties of a tied column is governed by three factors: 1. Should not be more than 16 times the diameter of the longitudinal or main reinforcing bar. 2. Should not be more than 48 times the diameter of the lateral ties. 3. Not more than the shortest dimension (side) of the column. To find the spacing of lateral ties required for a tied column, the following illustration is presented: Hlustration: Determine the spacing of the lateral ties for a tied column as shown on Figure 8 - 3.

~.20"""~

0 -

-lG,.m

.fO

'"'·

IQ.,..rn ...J

---IDN•m

\

Figure 8-3

Solution: a.

The diameter of the longitudinal bar is (3/4"1 or 20 mm The diameter of the lateral ties is (3/8") or 10 mm b. Multiply: 16 x 20 mm =32 cm · c. Multiply: 48 x 10 mm ::= 48 em d. The shortest side of column =30 em From the result·of the above computation, it could be readily seen that the least value found Is 30 em. therefore, the spacing of the lateral ties will be af 30 centimeters on center. When there are more than 4· vertical bars in a tied column, additional ties shaU be provided in order to hold the longitudinal bars firmly to its designed position. The Code further states: "the ties shall be so arranged that every corner and the alternate longitudinal bar shall have lateral support provided by the corner of the tie having an inclined angle of not more than 135 degrees and no bar shall be farther apart than 15 em clear on either side from such a laterally supported bar." 138

[g] J[: J: ll ~ lo~ ;orran~ttntno> ~onfurllliftlt

I.

111 ACI Coot .

II (

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J

Figure 8-4 Rein~ement Ratio 1nd Limitation =The size and number of steel bars be plac,ed in a tied co lumn is governed by the proportion of its cross sectional area to the gross area of the column.

to

"The cross sectional area of the vertical reinforcement shall not be less than .01 nor more than .08 times the gross area of the column section. ••

Illustration: Find the .mm1mum and maximum steel bats that could be placed in a tied column having a cross sectional dimension of (10" x 12") or 25 x 30 em.

. ,. D

. -...

~ I{) · 29 Mt'l"'l

-- ~·\C.mm .

MINIMUM REINFORCHIIEI/T

Figure 8-5

Solution: A -

Minimwn Reinforcement: a. Solvo for the cross sectional area of the column, 25 x 30 = 750 sq em (10" x 12""' 120 sq in) 139

b.

Solve for the minimum area of the vertical reinforcement. .01 x 750 = 7.5 sq. em. {.01 x 120 = 1.2 sq. in.) c. Convert this area to the size and number of steel bars by the aid of Table 5 -I. 9 Area of 4 pes. No. 5 (16 mm) bar = 8.04 sq. em. (Area of 4 pes No. 5 (5/8") bar = 1.24 sq . in.

8

Maxim lilt Reinforcement: a. .08 x 750 = 60 sq. em. (.08 x 120 = 9.6 sq. in.) b.

(English) Metric:

Table 5-2 shows that: 10 pes No. 9 bars gross area= 10.0 sq. in 8 pes. No. 10 bars gross area= 10.12 sq. in. 10 pes. 28 mm gross area = 61.6 sq. em. 8 pes. 32 mm grons area = 64.3 sq. em.

From the result of the above illustration, it appears that the minimum steel bars that could be placed in a 25 x 30 em. column are 4 pes 16 mm steel bars. Likewise, the maximum reinforcing bars that could be placed therein are ei't her 10 pes 28 mm or 8 pes 32 mm diameter. The above example shows how to determine the least and the most number of bars that could be placed in a tied column. Bundled Bars - Difficulties had been encountered in placing concrete inside the forms congested with steel bars. A column that is heavily loaded with reinforcement has this serious problem when large nu mber of steel bars are positioned and held indiv idually by lateral t ies. Bundled bars are sometimes employed consisting of 2 to 4 bars tied in direct contact with each other to serve or act as one unit reinforcement placed at the corner of the lateral ties.

·~•DLID

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Figure 8 · 6

140

~

18

16

- --

H

12

25 29

196 224 252 280

432

468

24 26

396

288 320 352 384

256

308

41

46 51 65 60

37 41 45 49

83

36 39

32

28 31

192

168

25

23

216 240

324 360

22

20

16

20

18

Mill.

ou B&l'll

P {ki~) - {0.18/',A,

115

166 184 203 221 240

131 H7 164 180 197

158

143

129

100

123

93 Ul

86

74

92

Ill 72 82

Mu.

-

29

75

69

58 63

52

41 46 51 56 61

49

45 '

31

86 40

23 'Z7 31 36 38

19 22 .26

Jdlu. 77

207 230 253 276 300

164 184 206 225 246

L25

143 161 179 197

92 108 123 138 154

115

00

102

+ 1000

156 168

143

117

130

1'Z7 138

115

92 104

111

101

91

71 81

86

88

211

146 i62 178 194

115

130 144 158 173

1.26 139

113

101

108

76

86 '¥7

78

69

65

81

72

M

ea

2600

190

~

.233

175 194 214

207

138 156 173

1011 121 136 151 100

130

117

1(K

91

'78

85 711 88 111

3000

!'.

~

316

292

243 267

219

173 194 216 238 259

132 151 170 189 208

146 162

tao

113

07

us

108

81

3760

x-d on Concrete 0.18J'.A1 + 1000

60

.s2

43 50 58 65

2000

+ 0.8/,A,)

Jdu.

J.- 20,000

Mlu.: 0.008/,Al + 1000 Mas.: 0.032/, ' + 1000

Loed

Pari 1.

ALLOWABLE LOAD ON A TIED COLUMN

' · - 16,000

18 22

144

18

18 20 22 24

---16

16 18 20 22

14

12 14 16 18 20

180

120 140 160

16 18

a

12

10

A,

Al"e&

Colultlll Size

G...,.

TABLEB -2

230

•zt

29.2 3.24 356 389

346

317

288

.259

176 202 2'Z7 252 27'7

130 151 173 194 2111

1112

108 1211

1«

11000

...

),)

84

!

I6

61

66 80

120

77 98

"

81 10! 130 160

61

32

Ill

t5

24

84

612

401 + 1000

+ 1000

JnO

154 177 2101

m

2M 2M S14

till

415 452

346

-1.50

380

780

120

703

~ ~

564

az.s

S5a

221

Zit

3015 '"

337

m

408 4411

SZ7

510

816

1131 573 816 661 8(M

7ffl 756 8M

Load OQ

SPIRAL COlUMNS. LOAD OH GROSS SECTION

f.

17l lN Si t 244

270 2118

357

422

I.

.. --.. m

3Z7

.all

1111

388

...,

t.o.d c.. Cooerete

tal)

eoa-.

m

110 181

lU

• 1112 203

248

225

Its

212 288

218

324 862

456

Me

492

10 13

880

760

710

1081

882

0f07

9111

5111

eo8 735

· -~~

608

328 410 353 441 878 . 473

613

MO 67t

1151 122&

405 433

4.61 490

6481811 1181 11M

ao.

238

259 281

14& 1&2 180

116

130

101

o..=r~,

TABLE 8- 4 8quano

Ban

t5 11 68

• M

12 80 88 97 106

116 126

135 14& 157

188 192 206

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1.-1

1.-to.ooo

OD

lAM

1.- ts.ooo

31

68

52

ce

3a ·&1

xt.. x!a. ..... M1... ~ .....

-71

cu.

441

361 4.00

21

18 Ill 20

'I? 86

484 92

100 108 117 12&

185

1n

1M

tu 374 180

S41

154

1088

1024

!.lOO

,.,;;t

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ne

626

629

12 28

578 i

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k 26

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2e 27 28 .29 SJ

12 88

from Rart/rwutl. CoJOCrCt• Dui~rt H..Ubol:,

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63

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178

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711 108 142 180 229 281

70

116 128 HIO 203 250

56

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200

22$

183

163

Z79 3-t3

25.1 812

200

132 174 220

97

68

120 168

112 88

275

224

126 160

114 144

128

203 260

116

71 101

67

66

17 106 139 176

70

-

37-l

74 106 144 190 240 305

300

192 244

162

00 M 115

1101111121

60

9

45

I

63 86

8

40 56

I

86 411

7

88 112 IU 175

I

371

Ill 110

18

15 16 11

fll

122 lliO

116

16

42

fll f lO

30

f/j

6

te

8iae

B.r

- --

805 314

240

1110

381 468

300

237

182 180

113

- -

356 481

280

221

f¥1

156

4.06

74

106 144

711

liQ&

826

258

154 202

113

424

146

163 215 272

84 120

88

«II

866

2811

228

127 178

I 99

499

406

320

263

192

HI

432 631

340

269

204.

lli()

105

562

360 457

5113

380 483

300

223

118

167

112

158 216 284

240 304 3811 414

182

114

IN

llG

Rail or Hard Grade: 1. - 20,000

28& kll

224

lM 177

69 99

205 2M 830

l1a

Intetmediat. Grade: I.- UI,OOO

Ia• lu It& In

123 168

IH

81

a:u·

2M

208

126 164

92

M

18

Number ol Ban

ZI

624

508

316 400

240

124 176

lOt

66.'1

634

~20

252 332

130 185

624

U"T

JM

14.1 2lln

.. 400

320

m

•

1U 19%

20

440 569 686

264 848

194

138

549

IOD LIS 211 278 &52 447

488

467

718

384

364 460

276

143 202

67~

149

740

480 610

379

211 288

ne

811

520 G60

411

112

229

161

640

521

329

260

Ul8

129

- - -

305 600 685 780

300

15.5 220

824

400 508

m

316 ~1

384

240

124 176

303

230

111 1811 368

1Q 221

·u•

I I 1211Z812~juJH

(Mai . ..t • - 0.08A1)

SPIRAl COLUMNS. LOADS ON lARS

r-d on Bart, A. {kipe) •/..&0 + 1000

TABLE 8- 5

S.r SiH

15

Ring

0 I

0

10 10 $

11

7

u 11

•

1a

12

9

u

u 1 tf 10 • 11

.

d:~o(Core

22

21

28

29

26

21

26

:10

81 26

24 1$

23

18

24

17

23

30 25

26

18

1':'

29 24

23

27 23

19

22

21

18

26 21

25 20

22 1T

13

21 16

u,

20

26 21

24

2!

.23

24

22

HI 15

,_

Manmum Number of S.ra io Out.~: ~line. 0, aod in 11111« RiDe. I

10 8

~~~"

TABLE 8- 6

9 4

7

7

9

$

4

7

6

8

10 6

11 7

9 5

5

9

7

9

9 4

\)

7

6

9

11 7

9

14 10

13

12

9

11

-

11

14 10

7

12

11

13 tl

14

13 7

13

HI II 1---

17

10

14

11

13

6

18

-

11 6

6

li

6

11

--

10

·

9

10

-

IS

20

13

7

9

17 12

-

lll 14

18

20 IS

17

16 ll

14

16

8

9

15

--

14 9

7

16

9

19 lli

c-.u DuiiJI Ha~.

22

20 16

16

14 9

16 10

19 13

21 17

;ao

--

27

12

27 :.!2

;--

20

211

18 12

H

16

22

20

24

18

12

15

ll3

Ill

20

11

18

14

16 11

20

17

- --0 a II 16 18 19 21 25 16 21 28 u 19 1 1 8 14 18 "u --- --17---- - - - - -0 8 to u 16 18 21 23 l a 9 12 17 18 19 -- - 0- - - -- - - -- - - ,_ -- 22 13 18 8 15 18 18 I 8 8 9 13 19 - - - --1 - ---- - - ------ ---- - - - - -0 6 8 10 18 21 19 15 17 I 6 8 9 10 12 13 - - - - --. - -s f--- 10- - - - - ·- 12 ----- -- - -f, ,0 8 19 8 13 15 17 17 18 19 I 12 13 13 7 8 8 10 u 12 - - - - -- 1- ----- -7- · 8- - - --!-:--- - u - ·- ----------,11 12 12 13 14 17

~_I~ =

AmMican Concrete l.o.atitute {rom Rftrt/tNUtl

lot\

-.

CJt

Ut

1t

12

13

14 15 18 17

18 19

14

16

18

17 18

21

22

23

2'

.2$

27

aa

10 Sl 32

lit

•

21

25

ao

20

26 26 · Z7 28

20

22 23 24

IQ :.0

Diameter

I Con

Slae

Coh•mn

K-2

H-2K H-2

H-2~

:K--2J.1 K-2K K-2J.1

}i-2J.S H- 2J.S K-2J.S .J.S-2)(

u-zu u--zu

•

H-2~

~2)(

u-zu

)f-2"

H-2 ~, ~-2 }! H-2 }~

H-2J.S

H-2J.S Ji-2J.S J.S-2J.S

~-2J.S

Jt-2" H-2"'

~-2U Ji-2~

~2J.S

Jt-23(

~-.2

~2

I

3750

I

5000

2000

• • •

• • •

,.,...2

~-2

H-2 H-2

,.,...2

H-2 H-2

Uo-2)(

~-2.1-t

Jt-2~

u-zu

•

Uo-2 J+-2

•

•..

•

•

•

• • •

• • • • • •

•

•

•

•

•

H-3 Jr3

~

H-3

J+-3

~

H-3

~3

~3

K-3

~

H-2J.1

Jf-2)(

u-zu

H-2~

H-2)(

~2)(

)f-2)(

H-2)( Jf-2)( *2K H-214:

H-2~

)f-2)(

~

' )f-2)( K-2)( Jt-2U Jt-2!{

u-2

~I"

~2

2300

H-3

K-2U K-2J.S Jf-2"'

~%)(

~2

~·"'

~2

Hot-Rollecl 1 :K-In. Cooeret.e ~n

3ooo

H-2U

I

Jt-2U

Jt-2"

,....2"'

H-2"'

U-3

~

}i-2 :K--2 .li--2 .li--2 K-2

K-2

Ji-2

H-2"'

Jf-2!{ Jf-2!{

•

Ji-2 }i-2

2500

u-zu

'i-2 !{ Ji-2J.S

}i-2 }i-2

•

2000

I

COLUMNS. $IZ! AND PITCH Of SNAl$

Sq U&('l ColuiZl.ll I 1-~---,--~---1·

TABLE 8 - 7 SPII~.L

I

K-2 '

)f-2·

*2 )f-2

K-2 H-2 H-2

H-2

~2 ~2

H-2 )f-2 ,.,...2

~·"' K-2 H-2

K-l"'

~·"'

~~"'

*•"'

3000

H-2"

)t-2J( .J.S-2"

K-2"' K-2"' )f-2"'

H-2"'

K-2U K-2"'

J+-2)( Ji-2J.S J+-2H K-2U

••

Ji-2 }i-2

8760

~

Ji-.2"

u-2"

. H-2"

·I

RoiUI-4.

fl__

i. I

Figure 9-20

9- 10 BEAMS REINFORCED FOR COMPRESSION When Architectural conditions limit the cross sectional di~ mension of the beam, it might be possible that the area of the concrete that will resist the comJ'ression load becomes smaller · and insufficient. Under this situat•on, steel reinforcement is substituted in place of the concrete area deficiency to supple· ment the ~oncrete in counteracting compression stresses. This type of beam is called .. Double Reinforced Beam" where stirrups or ties are used to hold the reinforcement together in position spaced not further apart than 16 times bar diameter or 48 tie diameter. · If compression bars are used in a flexural member, care should be exercised to ensure these bars from buckling outward spalling off the outer concrete when under load. The reinforcing bars should be properly anchored in the same manner as the compressive bar·s in column are anchored by lateral ties. Such ties must be used throughout the distance where the compression reinforcement is required.

f.-

\t·••

+

T

• r!-• l--6=-l Double Rtlnforcement

Figure ~21

176

d

9- 11 WEB REINFORCEMENT Web reinforcement Is the same as the strirrups used in the beam to hold the reinforcement in its designed position. The web reinforcement is not only intended to hold the reinforcement and provide lateral support but also serves to resist- diagonal tension and counteract the shear action on the structure. The vertical stirrups should encircle the main reinforcement and hook bent w ith a diameter not less than 5 times the diameter of the stirrups at its end and secured prop.e rly to prevent slipping of the main reinforcement in·i he ~oncrete.

U-stirrups

Closed stirrups Figure 9-22

9- 12 TORSION IN REINFORCED CONCRETE MEMBER To resist torsion, the structure must consist of longitudinal reinforcing bars provided with closely spaced stirrups. The UStrirrups commonly used for transverse shear reinforcement are not suitable for torsional reinforcement, instead, a lateral ties used in column is being employed as stirrups which is effective In counteracting torsional stresses. Good anchorage is by hooking the stirrups bar end around the longitudinal or main reinforcement. If flanges of a T·Beam are included in the computation of torsional strength, a supplementary slab reinforcement should be provided. The main reinforcement should be well-distributed around the perimeter of the cross-section to control cracking. Spacing must not exceed (12") 30 em apart. Bars should not be less than No. 3 in size and at least one bar must be placed in each corner of the stirrups.

177

~oo1r panel is nearly square is generalfy economical to employ the two directions of reinforcing bars placed at right angle with each other. This type of reinforcement will transmit the loads to the four sides supporting beams or walls. The code specifies that .thickness of the slab shall not be less than 4 inches or 10 em. nor less than the perimeter of the slab divided by 180. The spacing of the reinforcement shall not be more than 3 times the slab thickness and the ratio of reinforcement shall be at least .0025. 183

Construction Joints:

The ACI Code on construction joints

so provides: 1. Joints not indicated on the plans shall be so made and located as not to impair significantly the strength of the structure. Where a joint is to be made, the surface of the concrete shall be thoroughly cleaned and all laitance and standing water removed. Vertical joints shall also be thoroughly wetted and coated with neat cement grout immediately before placing of new concrete. 2. A delay of at least until the concrete ir columns and walls is no longer plastic must occur before casting or erecting beams, girders, or slabs supported thereon. Beams, girders, brackets. column capitals, and haunches shall be considered as part of the floor system and shall be placed monolithically therewith. 3. Construction joints in floors' shall be located near the middle of the spans of the slabs, beams, or girders, unless a beam intersects a girder at this point, in which case the joints in the girders shall be offset a distance equal to twice the width of the. beam. Provision shall be made for .transfer of shear and other forces ~hrough the construction joints.

Placement of Steel Bars - Where no ~ent bars are used in the slab reinforcements, straight bars are used for both the top and the bottom reinforcements. The bottom bars are extended at least 15 em. into the supporting beams or walls. The top bars are extended to t point of the adjacent panels. Top bars for discontinuous floor edges shall be hooked. (See Table 9 · 5).

_jl ....

L-:

II

\I

·--

A

'I

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TABLE 9 -4 MINIMUM LENGTH OF SLAB

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EN O JOINT WITHOU T SHOE .ANGLIES

OI!SIGN OF £NO J "OINT WITH SHOE ANGLE·

210

10- 21 ROOF TRUSSES Roof trusses is the most economical structure to cover a building having a wide span of supporting columns or walls. A truss is a structural frame generally supported only at both ends by columns, beams, or walls.

The different types of trusses are:

1. King post truss 2. Simple fh1k truss 3. 'Fink truss

7. Single span fink truss 8. Clipped truss 9. Rigid frame open-web clear span truss 10. Rigid frame clear span 11. Single span slope beam

4. Howe truss 5. Pratt truss 6. Fan Truss ·

12. Continuous Seam

~~ SIMPLE FllfK TIIUSS

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Figure 10- 22

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PURLINS: Purlins is a beam placed on top of the rafters or top chord that extends from truss to truss which carry and transfer the roof load to the truss at the panel points.

Roof Panel: - Refers to the roof portion that Hes between two adjacent joints of the upper chord, in short, roof panel is that portion of the roof supported by each purl ins.

Sag rods: - Refers to a steel bar usually of 16 mm or 19 mm diameter rod attached at the center or endpoints of the span of the purlins. Sag rod is secured to the purl ins over the line of the ridge truss usually placed at 7 em. below the top flange of the purl ins. Root ?a"nal

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Figure 10 - 23

10-13 WELDED CONNECTIONS The advantages of using welded connections are: 1. Minimal noise in the erection of structure 2. Savings on labor and materials 3: Rigidity of frame 4. Easy to correct new work to existing structure and also its repair. 5. Simplicity of design

212

Arc Welding:- Although arc and gas welding are permitted in the connection of structural steel members, arc welding is the one most preferred. Penebatlon: - Is the term used to indicate the depth from the original surface of the base metal to the point ·at which fusion ceases. Partial penetration: - is the failure of the weld metal and base metal to fuse at the root of the weld.

Welded Joints:- Are classified into three: 1. Butt joint 2. Tee Joint 3. Lap Joint The selection of the type of weld to be employed depends upon the magnitude of the load requirements, the manner in which it is applied, and the cost of the preparation and welding operation. The weld that is commonly used in building construction is the fillet weld which is somewhat triangular in cross section form· ed between the intersecting surfaces of the joined members. The minimum effective length of a fillet weld shall not be less than 4 times the weld size. The 5 mm fillet weld is considered the minimum size and an 8 mm weld is the most economical size that · could be made by one pass of the electrode. A small size conti· nuous weld is more economical than a bigger discontinuous weld. Large size fillet w~ld requires two or more passes of the electrode.

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Figure 10 • 24

213

Shop Weld: - Where the structural members are welded in the shop before delivering at the site.

Field Welding: structural members.

Welding done during t he erection of the

Plug and Slot Welds: - In connecting two overlapping plates by means of welding, holes are made in one of the two plates then plug and slot welds are made at the entire area of the hole or slot. The maximum and minimum diameters of the plug and slots including its length are shown on the following illustration: .a. ........ . .. . ,.,., .... D. ~ ... ~'" """ '•

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