A Self-Learning Manual - Institution of Engineers Mauritius

More documents

Recommendations

Info

A Self-Learning Manual Mastering Different Fields of Civil Engineering Works (VC-Q&A Method) Vincent T. H. CHU Sawing cannot be implemented too late. When the volume of concrete is reduced significantly owing to drying shrinkage or thermal contraction, it induces tensile stress owing to the restraint of such reduction. When the tensile stresses exceed the tensile strength of concrete, cracking would result and form in other locations instead of the planned location of contraction joints. 20. For box-out of concrete carriageway, should square box-out or round box-out be adopted? (C3) Isolation joints are introduced where the pavement contains manholes and other structures. The joints allow independent movement of the pavement and roadside structures without any connection which otherwise could result in damage. Square box-outs are commonly used in pavement and it suffers from the demerit that cracks are observed to appear at the corners of the box-out. Hence, to prevent crack formation at corners, the use of rounded box-outs could eliminate such occurrence. In fact, some form of reinforcement could be introduced to reduce the crack formation in square box-outs. For instance, fillets or reinforcing bars and fabric could be placed at interior corners of square box-outs to hold the cracks together should cracks grow. 21. What is the significance of ten percent fines value in testing sub-base material? Ten percent fines value is a measure of the resistance of aggregate crushing subjected to loading and it is applicable to both weak and strong aggregate. Fine aggregates are defined as those passing 2.36mm sieve. The test aims at looking for the forces required to produce 10% of fine values (i.e. weight of fines aggregates/weight of all aggregates = 10%). This test is very similar to Aggregate Crushing Test in which a standard force 400kN is applied and fines material expressed as a percentage of the original mass is the aggregate crushing value. Granular sub-base is subjected to repeated loadings from truck types. The stress level at the contact points of aggregate particles is quite high. The sub-base in pavement is a structural layer used for distribution of traffic loads into larger area. As such, it is of paramount importance that the sub-base material should itself not be disintegrated under severe traffic loads. Ten percent fines value can be used to reveal the aggregate properties when subjected to mechanical degradation. 262
A Self-Learning Manual Mastering Different Fields of Civil Engineering Works (VC-Q&A Method) Vincent T. H. CHU 22. What is difference in purpose for conducting surface regularity test and sand patch test (test on texture depth)? (T2) The purpose of surface regularity test is to measure the riding quality of pavements and the same requirement and standard is applied to both concrete and bituminous carriageway. On the other hand, sand patch test is used for checking the skid resistance of road pavements. Moreover, it is related to traffic noise because the intensity of noise generated from road traffic is related to texture depth of carriageway. 23. Does the use of concrete road enhance fuel saving when compared with bituminous road? Concrete road belongs to rigid pavement and they do not deflect under traffic loads. On the contrary, bituminous pavement deflects when subjected to vehicular load. As such, for concrete road no extra effort is paid on getting out of deflected ruts which is commonly encountered for bituminous pavement. Hence, vehicles using concrete road use less energy and there is about 15-20% less fuel consumed when using concrete road when compared with bituminous road. 263
Page 1 and 2:
A Self-Learning Manual Mastering Di
Page 3 and 4:
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212: A Self-Learning Manual Mastering Di
Page 261: A Self-Learning Manual Mastering Di
Page 313 and 314:
Page 315 and 316:
Page 317 and 318:
Page 319 and 320:
Page 321 and 322:
Page 323 and 324:
Page 325 and 326:
Page 327 and 328:
Page 329 and 330:
Page 331 and 332:
Page 333 and 334:
Page 335 and 336:
Page 337 and 338:
Page 339 and 340:
Page 341 and 342:
Page 343 and 344:
Page 345 and 346:
Page 347 and 348:
Page 349 and 350:
Page 351 and 352:
Page 353 and 354:
Page 355 and 356:
Page 357 and 358:
Page 359 and 360:
Page 361 and 362:
Page 363 and 364:
Page 365 and 366:
Page 367 and 368:
Page 369 and 370:
Page 371 and 372:
Page 373 and 374:
Page 375 and 376:
Page 377 and 378:
Page 379 and 380:
Page 381 and 382:
Page 383 and 384:
Page 385 and 386:
Page 387 and 388:
Page 389 and 390:
Page 391 and 392:
Page 393 and 394:
Page 395 and 396:
Page 397 and 398:
Page 399 and 400:
Page 401 and 402:
Page 403 and 404:
Page 405 and 406:
show all

A Self-Learning Manual - Institution of Engineers Mauritius

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?