Concrete
Concrete is a construction material composed of cement, fine aggregates (sand) and coarse aggregates (Crushed or natural stones) mixed with water which hardens with time. Portland cement is the commonly used type of cement for the production of concrete. The proportion of Concrete: The proportion of concrete depends upon 1. cement, 2. sand, 3. aggregates and 4. Water. A mixture of Portland cement and water is called a paste. So, concrete can be called a mixture of paste, sand and aggregates. Sometimes rocks are used instead of aggregates. The cement paste coat the surface of the fine and coarse aggregates when mixed thoroughly and binds them. Soon after mixing the components, hydration reaction starts which provides strength and a rock-solid concrete is obtained. Materials are mixed in specific proportions to obtain the required strength. T...