Field test for cement | quality check of cement in site

Field test for cement              1.      Colour        2.      Physical properties        3.      Presence of lumps        4.      Strength 1. Colour             The colour of cement should be uniform. It should be typical cement colour that is grey colour with light greenish shade. This is not always reliable test but it gives an indication of excess of lime or clay and degree of burning 2.  Physical properties             The cement should feel smooth when touched or rubbed in between fingers. If it is felt rough, it indicates adulteration with sand. If hand is inserted in bag or heap of cement, it should feel cool and not warm.             If a small quantity of cement is thrown in a bucket of water, it sinks and should not float on the surface. A thin paste of cement water should feel sticky between the fingers. If the cement contains too much of pounded clay and silt as an adulterant, the paste will give an earthy smell. 3. Presence of lumps             The cement should be free from lumps.  Such lumps are forced by the absorption of moisture from the atmosphere. Any bag of cement containing such lumps should be rejected. 4. Strength             A block of cement 25mm* 25mm and 20mm long is prepared and it is immersed for 7 days in water. It is then placed on a supports 15cm apart and it is loaded with weight of 340N.the block should not show signs of failure.