Limestone is a sedimentary rock composed mostly of the mineral calcite and comprising about 15% of the Earth's sedimentary crust. It is a basic building block of the construction industry (dimension stone) and a chief material from which aggregate, cement, lime and building stone are made. 71% of all crushed stone
Nature and Occurrence. Limestone is a relatively common sedimentary rock formed from remains marine organisms such as coral or other invertebrates, and composed largely of calcium carbonate and other carbonates.
Crushed limestone is interground with clinker to produce cement, reducing the needs for clinkermaking and calcination. The addition of up to 5% limestone has shown to have no negative impacts on the performance of Portland cement, while optimized limestone cement would improve the workability slightly.