There are five different types of Portland cement, all containing approximately seventy-five percent calcium silicate. They differ in their maturing time and settling agent components,
which are typically gypsum. Ordinary Portland cement, also known as
Portland concrete cement
is the most common type used in construction. It is a versatile material, used in virtually every construction project where the strength and durability are important. It can be used for floors, sidewalks, buildings, and pavements, as well as masonry units and bridges.
Portland cement is made from lime, silica, and alumina. It contains a small amount of ferric oxides, which are impurities that form major unhydrated cement phases. These impurities are generally referred to by chemical abbreviations, which abbreviate the oxide formula to the first letter. Some of these minerals are di- and tri-calcium silicate, tri-calcium aluminate, and tetra-calcium aluminoferrite. The amount of these elements determines the performance and hydration of cementitious SSCs.
A cement’s composition is determined by its composition. In general, cements are classified as either Type I or Type II. The difference between the two is that the former has lower C 3 A content than the latter. It is also stronger than the latter, but has a lower compressive strength at early ages. To qualify as a cement, its paste must be strong enough after one day or three days of hydration. There is no minimum strength requirement for the latter two types, but it should meet minimum requirements in most situations.