What is concrete? Its ingredients? | Q & A

Concrete is a composite construction material formed by mixing a binding material (cement) with fine and coarse aggregates and water.
After mixing, it sets and hardens due to hydration of cement, forming a stone-like mass capable of resisting high compressive loads.

In simple terms:

Concrete = Cement + Aggregates + Water (+ Admixtures if required)

Ingredients of Concrete 1. Cement (Binding Material)

• Acts as the glue that binds aggregates together

• Common type: Ordinary Portland Cement (OPC)

• Provides strength and durability

2. Fine Aggregate

• Usually natural sand or manufactured sand (M-sand)

• Fills voids between coarse aggregates

• Improves workability and finish

3. Coarse Aggregate

• Crushed stone or gravel (generally 10 mm, 20 mm, or 40 mm)

• Provides bulk strength and reduces shrinkage

• Main load-carrying component

4. Water

• Required for:

  • Hydration of cement

  • Workability of concrete

• Should be clean and potable

• Excess water reduces strength

5. Admixtures (Optional)

• Added to improve specific properties

• Common types:

  • Plasticizers / Superplasticizers (increase workability)

  • Retarders (delay setting time)

  • Accelerators (speed up setting)

  • Air-entraining agents

One-Line Interview Answer (Very Important)

Concrete is a composite material made by mixing cement, fine aggregate, coarse aggregate, and water, which hardens due to hydration and gains strength.