Cement specifications clearly needed a way of prescribing the fineness of cement, and the sieve method was written into standards in the absence of any more useful measure, despite the fact that it provided little guidance as to the likely quality of the cement, particularly as the number of different grinding technologies multiplied.
Concrete, usually Portland cement concrete, is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens over time—most frequently a lime-based cement binder, such as Portland cement, but sometimes with other hydraulic cements, such as a calcium aluminate cement.
The cement industry faces a number of challenges that include depleting fossil fuel reserves, scarcity of raw materials, perpetually increasing demand for cements and concretes, growing environmental concerns linked to climate change and an ailing world economy.
Find out more about our main types of cement.. Cement is the most widely used construction material worldwide. It provides beneficial as well as desirable properties, such as compressive strength (construction material with highest strength per unit cost), durability, and aesthetics to a variety of construction applications.
Bound or unbound? There are two classes of bedding material: hydraulically bound and unbound. Hydraulically Bound (HB) materials have the loose aggregate (the sand) held together by a binder, most commonly cement or hydraulic lime, while unbound material, unsurprisingly, have no binder present, meaning that the loose aggregate (sand) remains loose.