The compressive strength for OPC 43 grade cement is 43 Mpa and that for OPC 53 grade cement is 53 MPa. The unit MPa(Megapascal) is the unit for compressive strength.

You can determine the quality of cement on the basis of these tests:

1. Float test
2. Smoothness test
3. Smell test
4. Color test
5. Manufacturing test
6. Temperature test
7. Setting test

Store the cement in a dry place. Use the cement bag that hasn’t been used since a long time to avoid it from becoming solid.

The lifespan of cement depends on the way it’s stored. If the cement is stored properly satisfying the expected conditions, it can stay fresh longer for years. However, no matter how perfectly you store, the compressive strength of cement reduces over time. If cement unused for more than 2 years, it could see a decrease in its compressive strength more than double of its original compressive strength after manufacturing.

Cement comes in more than 5 types.

Ordinary Portland Cement(OPC) and Portland Pozzolana Cement(PPC) are the popular types.

The other cement types are — Rapid Hardening Cement, Low Heat Cement, Sulphate Resisting Cement, Quick Setting Cement, Blast Furnace Slag Cement, High Alumina Cement and White Cement.

The hardening of the cement on the concrete takes about 28 days. However, it takes 24 to 48 hours to make it dry enough that one can walk on.