Question

The field test for the quality of cement consists in putting a small quantity of cement in a bucket containing water. A good quality cement will:

• A. Immediately dissolve in the water
• B. Float on the water surface
• C. Sink to the bottom of the bucket
• D. Produce this steam

Answer 1

The correct option is B Float on the water surface

Following four field tests may be carried out to ascertain roughly the quality of cement:

(i) colour: Colour of cement should be uniform and greenish grey.
(ii) Physical Properties:

$\bullet$ Cement should feel smooth when touched or rubbed in between fingers. If it is felt rough, it indicates adulteration with sand.

$\bullet$ If hand is inserted in a bag or heap of cement, it should feel cool and not warm

$\bullet$ If a small quantity of cement is thrown in a bucket of water, it should float for some time before they sink.

$\bullet$ A thin paste of cement with water should feel sticky between the fingers.

$\bullet$ If the cement contains too much pounded clay and silt as an adulterant, the paste will give an earthy smell.

(iii) Presence of lumps: Cement should be free from any hard lumps. Such lumps are formed by the absorption of moisture from the atmosphere. Any bag of cement containing such lumps should be rejected.