Portland Pozzolana Cement (PPC) is manufactured by blending pozzolanic materials, OPC clinker, and gypsum either grinding them together or separately. Today Portland Pozzolana Cement is widely in demand for industrial and residential buildings, roads, dams, and machine foundations. Pozzolana is an important ingredient in PPC which is commonly used in the form of:

• Fly ash
• Volcanic ash
• Silica fumes
• Calcined clay

PPC is resistant to harsh water attacks and prevents the formation of calcium hydroxide at the time of cement setting and hydration. It withstands aggressive gases, thermal cracks, wet cracking, etc. The BIS quality specifications for Pozzolana materials used in PPC have been mentioned below:

• Fly ash – IS 3812:1981
• Calcined clay – IS 1344:1981

PPC is used in heavy load infrastructure and constructions such as marine structures, hydraulic structures, mass concreting works, plastering, masonry mortars, and all applications of ordinary Portland cement.

The OPC 43 grade cement is the most popular general-purpose cement in the country today. The production of 43 grade OPC is nearly 50% of the total production of cement in the country. The 43 grade OPC can be used for following applications:

• General civil engineering construction work
• RCC works(preferably where grade of concrete is up to M-30)
• Pre-cast items such as blocks, tiles, pipes etc
• Asbestos products such as sheets and pipes
• Non-structural works such as plastering, flooring etc.

The compressive strength of cement when tested as per IS code shall be minimum 43 MPa.

OPC 53 Grade cement is a higher strength cement to meet the needs of the consumer for higher strength concrete. As per BIS requirements the minimum 28 days compressive strength of 53 Grade OPC should not be less than 53 MPa. For certain specialised works, such as pre-stressed concrete and certain items of pre-cast concrete requiring consistently high strength concrete, the use of 53 grade OPC is found very useful. 53 grade OPC produces higher-grade concrete at very economical cement content. In concrete mix design, for concrete M-20 and above grades a saving of 8 to 10 % of cement may be achieved with the use of 53 grade OPC. 53 Grade OPC can be used for the following applications.

• RCC works(Preferably where grade of concrete is M-25 and above)
• Pre-cast concrete items such as paving blocks, tiles building blocks etc.
• Pre-stressed concrete components
• Runways, concrete Roads, Bridges etc.