Portland Pozzolana cement
On the basis of pozzolana added to PPC. It is divided into two parts. Flyash based Portland pozzolana cement and calcined clay based Portland pozzolana cement. PPC is maufactured either by grinding intimately together Portland cement clinker, gypsum and a pozzolana such as flyash, or by intimately and uniformly blending portland cement and fine pozzolana. The physical requirements of OPC and PPC are similar. Increased impermeability, lower heat of hydration, lower plastic shrinkage, reduced alkali- aggregate expansion, and improved resistance to aggressive chemical agents and corrosion are some of the major benefits to be derived from the use of PPC. In mass concrete construction, PPC concretes have shown rather better behaviour in request of cracking than OPC concretes because of lower heat of hydration. PPC ensures durability in addition to strength.