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
high-rise buildings involves the construction of lower levels firstly in which
they are not loaded for a period of a year and more. Substantial material
savings shall be resulted from using 56 or 91-day compression test results.
Moreover, with later ages of test results used, other cementing materials
can be incorporated into the concrete mixture which improves the durability
of concrete in terms of heat generation in hydration and other aspects.
9. What are the differences between shear slump and collapse slump
in slump test? (T3)
There are three types of slump that may occur in a slumps test, namely,
true slump, shear slump and collapse slump.
True slump refers to general drop of the concrete mass evenly all around
without disintegration.
Shear slump indicates that the concrete lacks cohesion. It may undergo
segregation and bleeding and thus is undesirable for the durability of
concrete [46].
Collapse slump indicates that concrete mix is too wet and the mix is
regarded as harsh and lean.
Fig. Type of concrete slump
10. If on-site slump test fails, should engineers allow the contractor to
continue the concreting works? (T3)
This is a very classical question raised by many graduate engineers. In fact,
there are two schools of thought regarding this issue.
The first school of thought is rather straightforward: the contractor fails to
comply with contractual requirements and therefore as per G. C. C. Clause
54 (2)(c) the engineer could order suspension of the Works. Under the
conditions of G. C. C. Clause 54(2)(a) – (d), the contractor is not entitled to
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