A Self-Learning Manual - Institution of Engineers Mauritius

A Self-Learning Manual
Mastering Different Fields of Civil Engineering Works (VC-Q&A Method) Vincent T. H. CHU
Fig. 3.1 Crack formation in non-uniform support
3. During the time of construction, cracks are likely to develop in
small diameter concrete pipes. Why? (C1)
During the construction of new pavement, vibratory roller and heavy
equipment are needed to compact the filling material and bituminous
material. These heavy equipment could generate very high impact load
with short duration on the concrete pipes. It requires an extremely even
and uniform support in order to safely support these loads. Therefore, it is
not uncommon that construction vehicles are primary source of
crack-producer and it usually results in the formation of circumferential
cracks.
4. Should air test or water tests be selected to test the leakage of
constructed gravity pipelines? (T1)
For gravity pipes, air tests or water tests are carried out after completion of
laying and jointing of the pipes. These tests are conducted to check the
watertightness of joints and to ensure the pipelines are free from damage
where leakage may occur.
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