04-04-2017, 02:49 PM
Aggregate is a collective term for mineral materials such as sand, gravel and crushed stone which are used with a bonding medium (such as water, bitumen, Portland cement, lime, etc.) to form composite materials (such as bituminous concrete and Concrete Portland cement). By volume, the aggregate generally accounts for 92 to 96 percent of bituminous concrete and 70 to 80 percent of Portland cement concrete. The aggregate is also used for basic and sub-base courses for flexible and rigid pavements. Aggregates can be natural or manufactured. Natural aggregates are generally extracted from larger rock formations through an open excavation (quarry). The extracted rock is typically reduced to sizes usable by mechanical crushing. The manufactured aggregate is often an indirect product of other manufacturing industries.
