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
any claims of cost which is the main concern for most engineers. This is
the contractual power given to the Engineer in case of any failure in tests
required by the contract, even though some engineers argue that slump
tests are not as important as other tests like compression test.
The second school of thought is to let the contractor to continue their
concreting works and later on request the contractor to prove that the
finished works comply with other contractual requirements e.g.
compression test. This is based upon the belief that workability is mainly
required to achieve design concrete compression strength. In case the
compression test also fails, the contractor should demolish and reconstruct
the works accordingly. In fact, this is a rather passive way of treating
construction works and is not recommended because of the following
reasons:
(i) Workability of freshly placed concrete is related not only to strength
but also to durability of concrete. Even if the future compression test
passes, failing in slump test indicates that it may have adverse
impact to durability of completed concrete structures.
(ii) In case the compression test fails, the contractor has to deploy extra
time and resources to remove the work and reconstruct them once
again and this slows down the progress of works significantly.
Hence, in view of such likely probability of occurrence, why
shouldn’t the Engineer exercise his power to stop the contractor and
save these extra time and cost?
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