Cement act as a binder in concrete. It binds sand and coarse aggregate together. It is not possible to check all the properties of cement on site, so we can do some basic field tests through which we can get a rough idea about the quality of cement.
In this article we are suggesting some simple tests which we can perform easily on site without any apparatus to find out the quality of cement on site.
1. Date Of Packing (Manufacturing Date):
We know that Strength of cement decreases as time goes on. In general we know that cement which is manufactured 3 months before from that day we use is not suitable for construction. As per IS specification this type of cement is to be tested in lab before using it.
2. Color of Cement:
In general cement is present in "Grey color" with light greenish shade. If excess Lime (or) Clay present in cement then its color will change. Check the color of the cement is uniform or not.
3. Lumps in the cement:
If cement catches moisture automatically lumps will form. Cement undergoes chemical reaction when it reacted with atmospheric moisture. This process is called "Hydration".
4. Float test of cement:
Take some quantity of cement and through it in a bucket of water. The cement particle should remain on the surface of water for a while, later it should sink and should not float on the water surface.
5. Smoothness test (or) Rubbing Test:
To test the cement smoothness take a pinch of cement and rub it between fingers. It feel smooth wile rubbing. If it is rough, it is a sign of cement adulteration with sand.
6. Cement Temperature test:
Insert your hand into a cement bag. It must give you a cool feeling. The cool feeling implies that no hydration reaction taken place in that bag of cement.
7. Shape test (or) setting test of cement:
Take a 100 grams of cement and mix it with water to make a stiff paste. Then make a cement cake with sharp edges and place it on a glass plate. Immerse this glass plate in the bucket of water for 24 hrs. Observe that, while settling the shape shouldn't get disturbed. A good cement should be able to set, not crack and attain strength in water. Cement is ready to set under water also and that is why it is also called "Hydraulic Cement".
8. Smell test:
Take cement into your palm and smell it, if we feel some earthy smell, then we can come conclude that the cement is adulterated with high quantity of silt and clay.
9. Strength test:
Prepare a block of cement 25 mm breadth, 25 mm height and 200 mm long. Immerse the block in water and cure it for 7 days. Place the immersed block on supports 150 mm apart and then load with a weight of 34 kg (or) 340 N. If the block which is made of good cement should not show any sign of failure.
10. Specific gravity of cement:
Cement is having specific gravity around 3.1 to 3.6 g/cc, check that the specimen cement is having a value in between it (or) not.
FAQ'S on checking the quality of cement in construction site
How to check quality of cement on site?
What is the cause of lump formation in cement?
How to test cement strength on site?
Why does cement need to be used within 3 months from its manufacturing date?
How to conduct smoothness test on cement?