SIGNIFICANCE OF FIELD TESTS
Field test of Cement is one of the most important activity to be done at site to ensure the quality of construction. Every structure comprises of hundreds of building materials like sand, cement, aggregates, bricks, tiles, marble, etc. For creating a quality structure, building material quality plays an important role and needs to be checked frequently at different stages of construction. Cement is the most significant material used in construction and is responsible for the overall strength of the structure. Cement quality has to be ensured strictly for ensuring quality in construction.
WHY FIELD TEST OF CEMENT IS CONDUCTED?
Cement plants are mainly located near limestone mines in remote locations. Cement companies produce clinker from a centralised clinkerization plant. Clinkers are ground at the clinkerization plant or conveyed to strategically located grinding units for grinding followed by packing of cement bags. Cement, manufactured and packed are conveyed and distributed to designated locations via road/rail.
During transporting there are chances of moisture absorption by the cement even after ensuring the best protection. The cement tends to harden after absorbing the moisture thereby hampering the quality. Because of these unforeseen issues, cement has to be checked for its quality before using it in works. The tests of cement are conducted in approved labs.
TESTS TO BE CONDUCTED ON CEMENT
Normally lab tests are conducted to ascertain the properties of cement. Lab tests require time, special types of equipment, and professionals for testing and interpreting the results. It may not be possible to check all the properties of cement at the site. To overcome this difficulty cement tests are categorised into two.
FIELD TEST OF CEMENT AT CONSTRUCTION SITE
The quality of cement can be confirmed with the help of some simple field tests. These tests do not require any sophisticated types of equipment and professional skills and get the results very quickly. By conducting these simple tests and analysing the results we will get an idea about the cement quality and can immediately decide on accepting or rejecting it. These are first look tests and quality of cement is ensured by its smoothness to touch, the colour of cement, etc.
Check the manufacturing date of cement
The cement has to be consumed within 90 days from the date of manufacturing when stored in ideal conditions. All cement bags have the manufacturing date and batch no printed on it. By confirming the manufacturing date we can have a fair idea about how old the cement is and can make a decision on using it.
Apart from this, all batches of cement bear a Manufacturers Test Certificate which can also be requested and checked to confirm the manufacturing dates.
Visual checking for Lumps
Cement can be checked for any visual lumps. The cement bag corners can also be pressed to confirm the possible presence of lumps. By this test, we can ensure the cement is hardened or not.
Feel a pinch of cement between the figures. Cement has to feel smooth and not grainy. By this test, we can rule out the presence of any adulterated material like sand mixed with cement.
Heat of cement
Insert hand into an open bag of cement. The hand feels cool if the cement is of good quality and not yet started the hydration process.
Cement colour is usually greenish-grey. We can check the colour of the cement and confirm it at the site. But cement colour can vary with ingredient source and type.
Water float test
This test is done to determine the presence of impurities in cement. A hand full of cement is thrown to a bucket of water. If it is a good cement without impurities or any foreign bodies, the cement floats for a while before settling down. The presence of impurities can immediately settle the cement into the water.
A thick paste of cement is placed on a glass piece and immerse slowly in water and kept there for 24 hours. The cement piece will retain its shape and sets without any cracks or changes in shape. This is considered as a good cement.
In case of any doubts in quality, we have the privilege to be in touch with the cement manufacturers through their customer services and can address our concerns. Laboratory tests can also be conducted to confirm field observations. Cement quality is an element that never has to be compromised on construction. Because cement is the most important material which determines the quality and life of a structure.
ALSO READ : WHAT ARE THE PROPERTIES OF CEMENT?