PCC (Plain Cement Concrete)

Plain Cement Concrete (PCC) is concrete without any steel reinforcement, used where the structural action requires only compressive resistance. Typical PCC grades are M5 (kerb stones, blinding), M7.5 and M10 (sub-base for floors, pavements, footing levelling), M15 (mass concrete fills, plain footing pads in mild exposure). Because PCC has effectively zero tensile capacity, it is restricted by IS 456:2000 to non-flexural applications. Any element subject to bending, lateral load, or tensile stress requires reinforcement and becomes RCC.

PCC's primary use on an Indian site is the levelling course (mud mat) under raft and footing reinforcement — typically 75-100 mm of M10 PCC poured directly on the prepared subgrade, providing a clean, level surface for placing rebar. Other common applications: blinding layer below grade beam reinforcement, kerb and channel construction in roads, plinth beams in load-bearing masonry buildings (where RCC ground beams are not specified), boundary wall foundations where the wall is masonry and only the foundation is concrete. PCC is also used for protective layers — for example, the 40-50 mm screed above waterproofing membrane in basements and over wet areas.

PCC is chosen for cost — typically 30-40% cheaper than RCC at the same grade because no steel is procured, fabricated, or placed. However, the temptation to use PCC where RCC is required is a common safety violation. Floor slabs supported on subgrade, ramps with slope, and any wall above 600 mm height in earth-retaining service all require reinforcement per IS 456 Cl. 5.1.1. Site engineers should refuse to pour PCC in any element with a tensile stress field — even small reinforcement (a single layer of T8 nominal mesh) converts the element to RCC and prevents brittle cracking.