Formwork for Concrete Structures, 4th Edition

Contents......Page 6
Preface......Page 18
Acknowledgments......Page 20
Abbreviations and Symbols......Page 22
Purpose of This Book......Page 26
Allowable Unit Stresses in Formwork Material......Page 27
Arrangement of This Book......Page 28
References......Page 31
Impact of Structural Design on Formwork Costs......Page 32
Suggestions for Design......Page 34
Dimensional Standards......Page 35
Economy of Formwork and Sizes of Concrete Columns......Page 36
Beam and Column Intersections......Page 37
Economy in Formwork and Sizes of Concrete Beams......Page 38
Economy in Making, Erecting, and Stripping Forms......Page 39
Removal of Forms......Page 40
Building Construction and Economy......Page 41
Economy in Formwork and Overall Economy......Page 44
References......Page 45
Behavior of Concrete......Page 46
Lateral Pressure of Concrete on Formwork......Page 47
Lateral Pressure of Concrete on Wall Forms......Page 48
Example 3-1......Page 49
Example 3-2......Page 50
Example 3-3......Page 51
Relationship between Rate of Fill, Temperature, and Pressure for Wall Forms......Page 53
Example 3-4......Page 56
Example 3-5......Page 57
Graphical Illustration of Pressure Equations for Walls and Columns......Page 58
Vertical Loads on Forms......Page 61
Example 3-9......Page 63
References......Page 64
Properties of Lumber......Page 66
Allowable Stresses of Lumber......Page 69
Adjustment Factors C[sub(M)] for Moisture Content......Page 71
Adjustment Factor C[sub(P)] for Column Stability......Page 76
Adjustment Factors C[sub(b)] for Bearing Area......Page 77
Example 4-2......Page 78
Plywood......Page 79
Plyform......Page 80
Equations for Determining the Allowable Pressure on Plyform......Page 85
Allowable Pressure Based on Fiber Stress in Bending......Page 87
Allowable Pressure Based on Shear Deflection......Page 88
Maximum Spans for Lumber Framing Used to Support Plywood......Page 89
Hardboard......Page 91
Steel Forms......Page 97
Plastic Forms......Page 98
Nails......Page 99
Lateral Resistance of Nails......Page 100
Toe-Nail Connections......Page 102
Withdrawal Resistance of Lag Screws......Page 103
Lateral Resistance of Lag Screws......Page 104
Split-Ring Connectors......Page 107
Shear-Plate Connectors......Page 108
Penetration Requirements of Lag Screws......Page 109
Concrete Anchors......Page 110
References......Page 111
Arrangement of Information in This Chapter......Page 112
Lumber versus Timber Members......Page 113
Equations Used in Design......Page 114
Analysis of Bending Moments in Beams with Concentrated Loads......Page 115
Analysis of Bending Moments in Beams with Uniformly Distributed Loads......Page 116
Bending Stress in Beams......Page 117
Stability of Bending Members......Page 118
Example 5-1......Page 120
Example 5-2......Page 121
Example 5-3......Page 122
Horizontal Shearing Stress in Beams......Page 123
Example 5-5......Page 124
Modified Method of Determining the Unit Stress in Horizontal Shear in a Beam......Page 125
Example 5-6......Page 127
Example 5-7......Page 128
Deflection of Beams......Page 129
Deflection of Beams with Concentrated Loads......Page 130
Deflection of Single-Span Beams with Concentrated Loads......Page 131
Example 5-8......Page 132
Multiple-Span Beam with Concentrated Loads......Page 133
Single-Span Beams with Uniformly Distributed Loads......Page 134
Example 5-9......Page 135
Table for Bending Moment, Shear, and Deflection for Beams......Page 136
Example 5-10......Page 138
Example 5-11......Page 139
Allowable Span Length Based on Moment, Shear, or Deflection......Page 140
Allowable Span Length for Multiple-Span Members with Uniformly Distributed Loads......Page 141
Stresses and Deflection of Plywood......Page 142
Allowable Pressure on Plywood Based on Bending Stress......Page 143
Example 5-13......Page 145
Allowable Pressure on Plywood Based on Rolling Shear Stress......Page 146
Example 5-15......Page 147
Allowable Pressure on Plywood due to Bending Deflection......Page 148
Allowable Pressure on Plywood Based on Shear Deflection......Page 150
Example 5-17......Page 151
Compression Stresses and Loads on Vertical Shores......Page 152
Example 5-18......Page 156
Bearing Stresses Perpendicular to Grain......Page 157
Design of Forms for a Concrete Wall......Page 160
Plywood Sheathing to Resist Pressure from Concrete......Page 161
Studs for Support of Plywood......Page 163
Wales for Support of Studs......Page 165
Strength Required of Ties......Page 167
Design Summary of Forms for Concrete Wall......Page 168
Bracing for Wall Forms......Page 169
Example 5-19......Page 171
Example 5-20......Page 173
Design of Forms for a Concrete Slab......Page 174
Loads on Slab Forms......Page 175
Plywood Decking to Resist Vertical Load......Page 176
Joists for Support of Plywood......Page 177
Stringers for Support of Joists......Page 179
Shores for Support of Stringers......Page 181
Minimum Time for Forms and Supports to Remain in Place......Page 184
Minimum Safety Factors for Formwork Accessories......Page 185
References......Page 187
Shores......Page 188
Wood Post Shores......Page 190
Ellis Shores......Page 191
Symons Shores......Page 193
Selecting the Size and Spacing of Shores......Page 195
Tubular Steel Scaffolding Frames......Page 199
Steel Tower Frames......Page 202
Safety Practices Using Tubular Scaffolding......Page 204
Horizontal Shores......Page 205
Shoring Formwork for Multistory Structures......Page 207
References......Page 208
Causes of Failures of Formwork......Page 210
Forces Acting on Vertical Shores......Page 211
Force Produced by Concrete Falling on a Deck......Page 212
Example 7-1......Page 214
Motor-Driven Concrete Buggies......Page 215
Impact Produced by Motor-Driven Concrete Buggies......Page 216
Examples of Failure of Formwork and Falsework......Page 218
References......Page 220
Forms for Foundation Walls......Page 222
Example 8-1......Page 223
Procedure for Erection of Forms for Footings......Page 227
Forms for Concrete Footings......Page 229
Additional Forms for Concrete Footings......Page 230
Forms for Stepped Footings......Page 232
Forms for Round Footings......Page 233
Placing Anchor Bolts in Concrete Foundations......Page 235
General Information......Page 236
Definition of Terms......Page 237
Designing Forms for Concrete Walls......Page 238
Table of Equations for Calculating Allowable Span Lengths for Wood Beams and Plywood Sheathing......Page 240
Design of Forms for a Concrete Wall......Page 245
Plyform Sheathing to Resist Pressure from Concrete......Page 247
Summary of Allowable Span Lengths for the Sheathing......Page 249
Studs for Support of Plyform......Page 250
Bearing Strength between Studs and Wale......Page 251
Size of Wale Based on Selected 24 in. Spacing of Studs......Page 252
Results of the Design of the Forms for the Concrete Wall......Page 254
Tables to Design Wall Forms......Page 255
Calculating the Allowable Concrete Pressure on Plyform......Page 256
Allowable Pressure Based on Fiber Stress in Bending......Page 258
Allowable Pressure Based on Bending Deflection......Page 259
Maximum Spans for Lumber Framing Used to Support Plywood......Page 260
Forms for Walls with Batters......Page 265
Forms for Walls with Offsets......Page 266
Forms for Walls with Corbels......Page 267
Forms for Walls with Counterforts......Page 268
Forms for Walls of Circular Tanks......Page 269
Snap Ties......Page 271
Coil Ties......Page 272
Taper Ties......Page 274
Coil Loop Inserts for Bolt Anchors......Page 275
Prefabricated Wood Form Panels......Page 276
Gates Single-Waler Cam-Lock System......Page 278
Forms for Pilasters and Corners......Page 280
Ellis Quick-Lock Forming System......Page 282
Jahn System for Wall Forms......Page 285
Modular Panel Systems......Page 294
Gang-Forming Applications......Page 297
Gang Forms......Page 299
Forms for Curved Walls......Page 301
Jump Form System......Page 303
Self-Lifting Wall-Forming System......Page 305
Insulating Concrete Forms......Page 306
References......Page 307
Pressure on Column Forms......Page 308
Designing Forms for Square or Rectangular Columns......Page 309
Maximum Spacing of Column Clamps Using S4S Lumber Placed Vertical as Sheathing......Page 311
Example 10-1......Page 312
Plywood Sheathing with Vertical Wood Battens for Column Forms......Page 313
Tables for Determining the Maximum Span Length of Plyform Sheathing......Page 315
Maximum Spacing of Column Clamps Using Plyform with Vertical Wood Battens......Page 317
Example 10-2......Page 318
Design of Wood Yokes for Columns......Page 321
Example 10-3......Page 323
Example 10-4......Page 324
Steel Column Clamps with Wedges......Page 325
Example 10-5......Page 326
Concrete Column Forms with Patented Rotating Locking Device......Page 328
Column Forms Using Jahn Brackets and Cornerlocks......Page 330
Modular Panel Column Forms......Page 331
All-Metal Forms for Rectangular Forms......Page 333
Fiber Tubes for Round Columns......Page 336
Steel Forms for Round Columns......Page 337
One-Piece Steel Round Column Forms......Page 339
Plastic Round Column Forms Assembled in Sections......Page 340
Spring-Open Round Fiberglass Forms......Page 341
One-Piece Round Fiberglass Column Forms......Page 342
References......Page 343
Concrete Floor Slabs......Page 344
Loads on Concrete Slabs......Page 345
Definition of Terms......Page 346
Spacing of Joists......Page 347
Example 11-1......Page 349
Use of Tables to Determine Maximum Spacing of Joists......Page 350
Size and Span Length of Joists......Page 352
Example 11-2......Page 355
Example 11-3......Page 356
Use of Tables to Determine the Maximum Spans for Lumber Framing Used to Support Plywood......Page 357
Stringers......Page 362
Forms for Flat-Slab Concrete Floors......Page 363
Forms for Concrete Beams......Page 365
Example 11-4......Page 366
Example 11-5......Page 368
Example 11-6......Page 371
Forms for Exterior Beams......Page 373
Form Details for Beams Framing into Girders......Page 374
Suspended Forms for Concrete Slabs......Page 375
Designing Forms for Concrete Slabs......Page 376
Design of Formwork for Flat-Slab Concrete Floor with Joists and Stringers......Page 378
Plywood Decking to Resist Vertical Load......Page 379
Joists for Support of Plyform......Page 381
Stringers for Support of Joists......Page 383
Shores for Support of Stringers......Page 385
Design Summary of Forms for Concrete Slab......Page 386
Minimum Lateral Force for Design of Slab Form–Bracing Systems......Page 388
References......Page 389
Ceco Flangeforms......Page 390
Adjustable Steel Forms......Page 391
Ceco Longforms......Page 392
Ceco Steeldomes......Page 394
Ceco Longdomes......Page 395
Plastic Forms......Page 396
Cellular-Steel Floor Systems......Page 398
Selecting the Proper Panel Unit for Cellular-Steel Floor Systems......Page 399
Horizontal Shoring......Page 400
References......Page 404
Geometry of a Circle......Page 406
Example 13-1......Page 407
Locating Points on a Circle......Page 408
Elevations of Points on a Circular Arch......Page 410
Forms for Circular Shell Roofs......Page 411
Space the Joists......Page 412
Design the Ribs......Page 413
Determine the Load on the Shores......Page 415
Centering for Shell Roofs......Page 416
Use of Trusses as Centering......Page 417
Decentering and Form Removal......Page 419
Forms for Architectural versus Structural Concrete......Page 420
Stained Concrete......Page 421
Form Liners......Page 422
Hardboard......Page 424
Form Ties......Page 425
Construction Joints......Page 426
Order of Erecting Forms for a Building......Page 427
Wood Molds......Page 430
Plaster Waste Molds......Page 431
Metal Molds......Page 433
Forms for Corners......Page 435
Forms for Roof Members......Page 436
References......Page 438
The Forms......Page 440
Yokes......Page 443
Form Jacks......Page 444
Constructing a Sandwich Wall......Page 447
Silos and Mills......Page 448
Tall Bridge Piers......Page 449
Towers......Page 450
Concrete Buildings......Page 451
Linings for Shafts......Page 453
Slipforms for Special Structures......Page 454
References......Page 455
Example 16-1......Page 456
Wood Forms for Deck Slab with Haunches......Page 462
Forms for Overhanging Deck Constructed on Exterior Bridge Beams......Page 463
Deck Forms Supported by Steel Joists......Page 464
Example 16-2......Page 469
Deck Forms Supported by Tubular Steel Scaffolding......Page 471
Adjustable Steel Forms for Bridge Decks......Page 472
All-Steel Forms for Bridge Structures......Page 474
References......Page 475
Advantages of Flying Forms......Page 476
Form-Eze Flying Deck Forms......Page 479
Versatility of Forms......Page 481
Patent Construction Systems......Page 485
References......Page 488
A: Dimensional Tolerances for Concrete Structures......Page 490
B: Guidelines for Safety Requirements for Shoring Concrete Formwork......Page 496
C: OSHA Regulations for Formwork and Shoring......Page 518
D: Conversion of Units of Measure between U.S. Customary System and Metric System......Page 530
E: Directory of Organizations and Companies Related to Formwork for Concrete......Page 532
B......Page 538
D......Page 539
F......Page 540
M......Page 541
S......Page 542
W......Page 543