Composition of Concrete

Composition of Concrete

Concrete is one of the most common construction materials worldwide. It is a mixture of coarse and fine aggregates, cement, water, air, and (mineral admixtures). 

1. Aggregates are natural rocks sourced from quarries or river gravels. In the Philippines, volcanic rocks basalt and andesite are commonly used as aggregates in the construction industry.

2. Cement (Portland Cement) is a substance composed of silicates and oxides often mixed with water to produce cement paste. This paste binds the aggregates and hardens to form concrete.

3. Water is used to hydrate cement in concrete mixtures. It enhances workability during production, but its amount must be moderated as it has marked effects on concrete strength.

4. Air in concrete is often entrained from the surroundings or as dissolved oxygen in the mixing water during concrete mixing.

All these components have significant impact on concrete strength and durability. Parameters such as aggregate type, cement type, water/cement ratio, and air void percentage can be identified and quantified using concrete petrographic examination.