The Star Portland Pozzolana Cement is a kind of blended cement that is produced in two ways. The process is either by inter-grinding of OPC clinker with gypsum and pozzolanic materials in certain proportions or grinding the OPC clinker, gypsum and Pozzolanic materials separately and blending them thoroughly in certain proportions. Pozzolana is a natural or artificial material containing silica in a reactive form. It may be further discussed, as siliceous and aluminous material that possesses little or no cementitious properties but, in finely divided form and in the presence of moisture, it will chemically react with calcium hydroxide at ordinary temperature to form compounds possessing cementitious properties. Pozzolana must be in a finely divided state, and then silica can combine with calcium hydroxide (liberated by the hydrating Portland cement) in the presence of water to form stable calcium silicates which have cementitious properties with the highest one day strength in the industry.
