Cement is one of the most important materials used in construction. The strength of a structure depends upon several factors, cement quality is one of them. To achieve the desired strength of concrete and to increase the longevity of structure good quality cement should always be used.
So it is important to check the quality of cement before using.
To check the quality of cement we need to pass some easy tests which are described below.
Different Tests conducted on cement
1. DATE OF PACKING:
The strength of cement decreases with time. First of all, check the manufacturing date in the bag before using. Generally, cement should be used before 90 days from the manufacturing date.
2. CEMENT COLOR:
The cement should be uniform in color. Good quality cement should have gray color with greenish shade.
3. CHECK FOR LUMPS:
No lumps should be present in the cement. Lumps are formed due to absorption of moisture from the climate.
4. RUBBING TEST:
Cement should feel smooth while rubbing in between fingers. If it gives a rough feeling that means cement is mixed with sand.
5 TEMPERATURE TEST:
Simply insert your hand into the cement bag, it should give cool feeling if its quality is good. Otherwise, you may feel warm because of hydration reaction.
6. FLOAT TEST:
Take some amount of cement and throw it in water. The cement should float for sometimes before it sinks in the water.
7. SETTING TEST:
Make a thick cement paste with water and immerse it in water for 24 hours. It should be set and should not develop cracks.
8. STRENGTH TEST:
Prepare a cement block of 25 mm x 25 mm and 200 mm in length. Now submerge it in water for 7 days. Now place it on supports 15 cm apart and load it with 34 kg weight. Block made from good cement.
These are the different tests done on cement