To determine the properties of cement, we perform various tests such as fineness test, soundness test, setting test, strength tests etc. These are all laboratory tests.
Many times, It is not feasible to check the quality of cement on-site at the time of preliminary inspection through the lab tests.
Even though. we can not check all the engineering qualities of cement on site. There exist some tests which give us a rough idea of the quality of cement.
These tests are known as the field tests on cement.
Various field test on cement
Colour of cement:
For this test one should open the bag and then take a look at the cement. The colour of the cement should be greenish-grey in colour. It should be uniform throughout the bag.
Presence of loops:
Thrust your hand into the cement. There should not be any lumps inside the bag. If there are any lumps in the bag then it should be rejected.
Since lumps are formed by the absorption of moisture from the atmosphere. It also provides the idea of whether the cement is fresh or not.
For this test, one should take a sample of cement from the bag and then throw it into the bucket full of water. It should float for sometime before settling in the water.
For this test pick up an inch of cement and feel or rub between the fingers. It should feel smooth. If it felts rough, it indicates the adulteration with sand.
It is conducted to know that the cement is pure or it is containing some impurities.
If a hand is inserted in a bag or heap of cement it should feel cool, not warm. It is performed for checking that the cement is in its workable condition or not.
Date of Packing Test:
It is important to check the manufacturing date of the cement. Usually, the cement should be before 90 days from the date of manufacturing. One must note that hydrophobic cement can be used in a place where prolonged storage is required for the cement. It is generally used at dam sites and at the ports.
|Age of Cement||% Reduction in strength of cement|
From the above table, it is clear that the strength of cement loses its strength over a period of time.
By using the above field tests on cement, we can ascertain the quality of cement quickly.