OPC vs PPC vs PSC

Think of Ordinary Portland Cement, OPC, as the base recipe, pure clinker ground into powder, and blended cements as variations on that recipe where a portion of the clinker is deliberately replaced with another material that brings its own useful properties. Portland Pozzolana Cement, PPC, replaces part of the clinker with fly ash, the power-plant byproduct covered elsewhere on this site, while Portland Slag Cement, PSC, replaces part of it with slag, a byproduct of steel manufacturing.

These aren't lesser substitutes chosen purely to cut cost, both blended variants genuinely improve on plain OPC in specific ways, better resistance to certain chemical attacks, lower heat generated during curing, which matters enormously for large concrete pours where excess heat can cause cracking, and generally better long-term durability, which is exactly why blended cements have become the dominant choice in Indian construction rather than a budget alternative.

The market numbers reflect this clearly, PPC alone accounts for roughly 65 to 70% of all cement used in India, PSC contributes a further 7%, leaving plain OPC at around 30% of the market, essentially reserved for applications specifically requiring OPC's faster early strength development, rather than the default choice it remains in many other countries.

This blended-cement dominance connects directly to two other stories on this site, it's part of why fly ash utilisation in cement runs so high, and it's part of why Indian cement's carbon footprint per tonne, the exact metric the Carbon Credit Trading Scheme now regulates, is genuinely lower than it would be in a market still dominated by plain OPC.