Testing of cement can be brought under two categories:
(a) Field testing
(b) Laboratory testing.
Field Testing
It is sufficient to subject the cement to field tests when it is used for minor works. The following are the field tests:
(a) Open the bag and take a good look at the cement. There should not be any visible lumps. The colour of the cement should normally be greenish grey.
(b) Thrust your hand into the cement bag. It must give you a cool feeling. There shouldnot be any lump inside.
(c) Take a pinch of cement and feel-between the fingers. It should give a smooth and not a gritty feeling.
(d) Take a handful of cement and throw it on a bucket full of water, the particles should float for some time before they sink.
(e) Take about 100 grams of cement and a small quantity of water and make a stiff paste.
From the stiff paste, pat a cake with sharp edges. Put it on a glass plate and slowly
take it under water in a bucket. See that the shape of the cake is not disturbed while taking it down to the bottom of the bucket. After 24 hours the cake should retain its original shape and at the same time it should also set and attain some strength.
If a sample of cement satisfies the above field tests it may be concluded that the cement is not bad. The above tests do not really indicate that the cement is really good for important works. For using cement in important and major works it is incumbent on the part of the user to test the cement in the laboratory to confirm the requirements of the Indian Standard specifications with respect to its physical and chemical properties. No doubt, such
confirmations will have been done at the factory laboratory before the production comes out from the factory. But the cement may go bad during transportation and storage prior to its use in works. The following tests are usually conducted in the laboratory.
(a) Fineness test. (b) Setting time test.
(c) Strength test. (d) Soundness test.
(e) Heat of hydration test. (f ) Chemical composition test.
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