Field Test For Ordinary Portland Cement
The colour of cement should be uniformly greenish Grey.
The cement should feel smooth when touched between fingers. If it is felt rough, it indicates adulteration with sand.
When hand is trusted into a bag or heap of cement, it should feel cool.
Cement should be free from any hard lumps. Such lumps are formed by the absorption of moisture from the atmosphere.
A small quantity of cement is thrown in a bucket of water, should float in case the cement is of good quality. If it sinks, it contains some impurities.
It should not feel oily when touched.
It should not change its color on heating on a hot plate for 20 minutes. Adulterated cement will change it's color on heating.
Three pats ( 75 mm X 75 mm X 25 mm in size) are made from the sample of cement using 28% water by weight. It should not give nail impression after 24 hrs and it should be difficult to break it with pressure of fingers.
A pat ( 75 mm in diameter and 12 mm thick) is made from the sample of cement. The pat is covered by moist cloth for 24 hrs. Then the pat is boiled in water for 6 hrs. The surface of the pat is observed. If the cement is sound, the surface should not develop a pattern of cracks.