RCC is a Reinforced Cement Concrete
It is a common trade term in Construction & Infra, commonly termed as Concrete.
RCC is concrete which contains Reinforcement bars or Rebars, generally, those rebars are of steel.
The constituents of RCC are:
- Reinforcement Bars (Steel Bars)
- Cement (Portland Cement [FlyAsh in recent times])
- Coarse Aggregates (Stone Chips/brick chips)
- Fine Aggregates (Crushed Stone or Sand)
When Reinforcement Bar is set up and is poured with Concrete, after curing the formation of Reinforced Cement Concrete is formed.
Like everyone would know, the Concrete is a most advanced construction material required and comes in variants.
The quality of the variant is derived from the purpose of use and relevantly the strength required for the purpose is decided.
Based on these parameters the Structural Designing Engineer would design a specification of the Structure.
The specification of the structure includes the use of specific grade of product to get the desired performance in terms of Strength & Durability.
The Concrete is one of the components of those specifications.
The formation of Concrete is achieved using a specific methodology:
- Nominal Mixes:
The Prescribed specification of concrete for proportions of Cement, fine and coarse aggregate. The standard cement to aggregate ratio delivering the adequate strength is called Nominal Mix.
Nominal Mix offers simplicity & posses marginal strength above desired strength.
- Standard Mixes:
Due to the required minimum strength in most of the specifications, the use of nominal mix is compromised, as the standard cement to aggregate ratio (by volume) vary widely in strength resulting in Under or Over Rich mix.
As per IS 456–2000 (revised in 2005); The concrete is been designated into the number of grades and abbreviated as M10, M15, M20, M25, M30, M35, M40 and so on;
The referencial proportion for M10 is (1:3:6), for M15 is (1:2:4), for M20 is (1:1.5:3) and for M25 is (1:1:2); where M refers to the Mix and the following number refers the specified strength at 28th Day in Cube Strength in N/mm2. and the number in bracket states Proportion of (Cement: Sand / fine aggregate : Stone pieces / coarse aggregate)
- Design Mixes:
In these kinds of mixes, the performance of concrete is defined and specified by the designer and the proportions are determined by the concrete producer. This is one of the most pragmatic approaches for determining the mix proportions with the use of specific materials and producing unique characteristics.
These kinds of mixes are a pragmatic approach to the production of the concrete most economically, however, the design mix is not a guide and doesn’t reward the correct proportional mix for prescribed performance.
Factors affecting the choice of mix proportions:
- Compressive Strength
- Maximum nominal size of Aggregates
- Grading / Type of Aggregates
in simplest way for all to know the Aggregates in RCC = Concrete – Cement
As, Concrete = Cement : Fine Aggregates : Coarse Aggregates (by volume)