ABSTRACT
Cement is a powdered hydraulic binder, which is characterized by the fact that the products of its hydration are air-resistant, damp-proof and stable even under water. Based upon composition, cements are divided into silicate, aluminous and special cements. Portland clinker provides the basis of silicate cements, with a setting regulator added and some hydraulic active or pozzolana additives. Aluminous cement is made of a mixture of bauxite and limestone, but this cement has not been used for structural concrete for more than 40 years because the conversion of hydration products leads to mechanical failures. Since the first half of 20th century, Portland cement has been the most frequently used cement.
