Every house uses both. Knowing which is which — and why — helps you read the drawings, check the work and order the right materials for each stage.
Why Does Concrete Need Steel?
Concrete is very strong in compression: it resists being squeezed. It is weak in tension, roughly a tenth as strong as in compression, so it cracks when pulled or bent. A beam under load bends, which puts its bottom face in tension. Plain concrete would crack and fail there.
Steel is strong in tension. Embedding steel bars in the tension zone lets the steel carry the pull while the concrete carries the push, and the concrete protects the steel from rust and fire. That partnership is RCC.
PCC vs RCC at a Glance
| PCC | RCC | |
|---|---|---|
| Full form | Plain Cement Concrete | Reinforced Cement Concrete |
| Steel | None | TMT bars as per design |
| Strength | Compression only | Compression and tension |
| Typical grades | M10, M15 | M20, M25 and above |
| Uses in a house | Footing bed, floor base, apron, levelling | Footings, columns, beams, slabs, lintels |
| Formwork | Usually minimal | Required for most members |
| Cost per m³ | Lower | Higher (steel, formwork, richer mix) |
Where Is PCC Used?
- Bed under footings: a 75–100 mm layer of M10 or M15 gives a clean, level surface for the footing steel and stops it touching the soil.
- Ground floor base: M15 over compacted fill, under the floor finish.
- Plinth protection: an apron around the building, sloped away, that keeps rainwater off the foundation.
- Levelling courses and non-structural paving.
Where Is RCC Used?
- Footings that spread column loads into the ground.
- Columns that carry each floor's load down.
- Beams — plinth, floor and roof — that carry slabs and walls.
- Slabs for floors and roof.
- Lintels and sunshades over openings.
- Staircases, sumps and overhead tanks.
Why Is RCC's Minimum Grade Higher?
The concrete in RCC has two jobs: carry compression and protect the steel. A lean mix is porous; moisture and air travel through it to the bars, which rust and expand, cracking the concrete from inside. IS 456 therefore sets a minimum grade of M20 for RCC in mild exposure and M25 in moderate exposure, with limits on water-cement ratio and minimum cement content, along with a minimum concrete cover over the steel.
What Does This Mean for Your Material Order?
PCC and RCC use the same ingredients in different proportions, plus steel for RCC. For a house, cement for the PCC beds and floor base is a small part of the total; the RCC frame and slabs take most of it, and all of the steel.
| Stage | Concrete type | Main materials |
|---|---|---|
| Footing bed | PCC M10/M15 | Cement, sand, aggregate |
| Footings and columns to plinth | RCC M20/M25 | Cement, sand, aggregate, TMT |
| Plinth beam | RCC | Cement, sand, aggregate, TMT |
| Ground floor base | PCC M15 | Cement, sand, aggregate |
| Columns, beams, slab | RCC | Cement, sand, aggregate, TMT |
The Short Version
PCC is concrete alone, for beds, bases and aprons, in M10 or M15. RCC is concrete with steel, for everything that bends or carries the building, in M20 or richer. If a member carries load across a span or up a column, it is RCC.
