### Strength of Cement - Building Research Institute

Back to Main Page. Strength of Cement Strength of cement is the most important of all the cement properties. Grades mentioned in the cement bags as 53/43 grade OPC/PPC in fact represent the strength of the cement. 53 Grade OPC Cement simply means that 28-days compressive strength of the cement-mortar cubes prepared out of that cement in a standard manner will be of 53 MPa.