Page 35 - HIGHWAY ENGINEERING LABORATORY_FLIP BUILDER

Page :
WORK INSTRUCTION
Edition :
Checking No.
SOUNDNESS TEST OF CEMENT

CIVIL ENGINEERING (Reference Standard: BS EN Effective Date:
196-3:2016 )
JKA/ DCC30112/ 2021 Amendment Date:

1.0 OBJECTIVE OF EXPERIMENT :

It is very important that the cement after setting shall not undergo any appreciable
change of volume. Certain cements have been found to undergo a large expansion
after setting causing disruption of the set and hardened mass. This will cause serious

difficulties for the durability of structures when such cement is used. The unsoundness in
cement is due to the presence of excess of free lime than that could be combined with
acidic oxide at the kiln. It is also likely that too high a proportion of magnesium content or

calcium sulphate content may cause unsoundness in cement. Soundness of cement may
be determined by two methods, namely Le-Chatelier method and autoclave method. In
the soundness test a specimen of hardened cement paste is boiled for a fixed time so
that any tendency to expand is speeded up and can be detected. Soundness means the

ability to resist volume expansion.

2.0 SUMMARY OF THEORY :
The soundness of cement may be defined as the property of which cement resists or

withstands the expansion due to slow or delayed hydration of free lime, magnesia and
calcium sulphate.

In other words, soundness can be defined as the ability of the cement to retain its

volume after it has hardened. The soundness test is an important test that is necessary for
evaluating the quality of cement to be used in the construction. This is because unsound
cement adversely affects the quality and strength of the construction. Soundness also

directly affects the durability of the structure. The soundness test of cement is mostly
conducted by Le-Chatlier’s Method

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