PPC is Portland Pozzolana Cement, is useful in general construction work and is especially suitable for applications in aggressive environmental conditions. It is mainly employed in construction of hydraulic structures, marine works, mass concreting such as dams, dykes, retaining walls foundations and sewage pipes.
Two types of Pozzolana that PPC utilizes:
| Fly ash | Calcined clay |
|---|---|
| Covered under IS:1489 (Part I) | Covered under IS:1489 (Part II) |
PPC provides improved workability, has less segregation and bleeding, increased water-tightness and reduced tendency of lime to leach out. It produces less heat of hydration and offers greater resistance to the attack of aggressive water containing sulphates and chlorides.
PPC is manufactured either by inter-grinding Portland cement clinker, gypsum and fly ash obtained from thermal power plants or by intimately blending OPC and fly ash. The percentage of fly ash in PPC permitted by IS:1489 varies from 15% (in minimum) to 35% (maximum). The minimum compressive strength of PPC after 28 days, as prescribed by BIS is 33 MPa or 330 kg / Cm2.