Here's why:
* Calcium Carbonate: Limestone is primarily composed of calcium carbonate (CaCO3), which is the essential ingredient for cement. When heated, calcium carbonate decomposes into calcium oxide (lime) and carbon dioxide.
* Availability: Limestone is one of the most abundant rocks on Earth, making it readily available and relatively inexpensive.
* Chemical Properties: The chemical composition of limestone allows it to react with other ingredients like clay and gypsum during the cement manufacturing process, forming the desired chemical bonds.
While limestone is the primary ingredient, other sedimentary rocks like clay and shale can also be added in smaller amounts to influence the properties of the cement.
