Portland Cement Types

The American Society for Testing and Materials (ASTM) Designation C150, which lists eight varieties of Portland cement, explains that different types are made to fulfil particular uses.

Cement – Type I

General-purpose type I cement is used to make floors, pavements, reinforced concrete structures, bridges, tanks, and pipes, among other concrete uses. It is perfect for concrete that isn’t exposed to harsh conditions like soil and water sulphate assault or unfavourable temperature increases.

Cement – Type II

When protecting drainage structures from moderate sulphate concentrations from groundwaters, for example, type II cement is used to prevent mild sulphate assault. Compared to Type I cement, it hydrates more slowly and produces less heat, which makes it appropriate for mass constructions such retaining walls, big piers, and hefty abutments. It is also better in hot weather due to its reduced heat generation.

Cement – Type III

Type III cement comprises finer particles and is comparable to Type I cement in terms of chemical and physical composition. It often offers strong early strengths in a week or less. It is used when forms must be swiftly removed or when the construction needs to be quickly placed into use. In colder climates, type III cement is recommended to shorten the curing time.

Cement – Type IV

When it’s important to minimise the rate and amount of heat created during hydration, type IV cement is used. In comparison to other cement kinds, its strength grows more slowly, which makes it appropriate for large-scale concrete constructions such major gravity dams, where temperature rise control is crucial to prevent concrete cracking.

Cement – Type V

Particularly in situations where soils or groundwaters have a high sulphate concentration, type V cement is employed in concrete exposed to severe sulphate action. Its low C3A level (about 4%) is responsible for its great sulphate tolerance. But it is not impervious to acids and other extremely corrosive materials.

Portland Cements via Air-Entraining
(IA, IIA, and IIIA types)

While the composition of these cements is the same as that of Types I, II, and III, respectively, during the manufacturing process, tiny amounts of air-entraining material are mixed in with the clinker. They yield concrete that is more resilient to the effects of freeze-thaw cycles and chemical-induced scaling that occurs during the removal of snow and ice.

Portland Cement- White

The composition of white Portland cement is identical to that of Type I or Type III cement; however, it is coloured white rather than grey. The grey colour of cement is caused by trace amounts of iron and magnesium oxides, which are present in certain raw materials used in its production. The main usage of white Portland cement is in architecture.

Blending Hydraulic Cements

These cements are made by mixing Portland cement with various pozzolanas, fly ash, blast-furnace slag, and silica fume byproducts. There are five classes of mixed cements recognized by ASTM C 596:

• Portland Slag Cement from Blast Furnace (Type IS)
• Portland cement (both Type IP and Type P)
• Portland cement treated with pozzolana (Type I(PM))
• Type S slag cement
• Portland cement treated with slag (Type I(SM))

Masonry Cements.

Masonry construction mortar is made with masonry cements. Masonry cements are divided into three types by ASTM C 91: Type N, Type S, and Type M.

Expensive Cement

As per ASTM C 845, expansive cements are categorised as Type E-1(K), Type E-1(M), and Type E-1(S). Their main purpose in concrete is to control shrinkage.

Special Cements (which ASTM does not cover)

Portland Cement’s Chemical Compound

As previously mentioned, the burning of the raw materials causes a reaction between the oxides, resulting in the formation of four compound compositions in the cement product as a whole:

• C₃S = 3CaO.SiO₂ (tricalcium silicate)
• C₂S = 2CaO.SiO₂ (dicalcium silicate)
• C₃A = 3CaO.Al₂O₃. (tricalcium aluminate )
• C₄AF = 4CaO.Al₂O₃.Fe₂O₃, (Tetracalcium aluminoferrite)

Compound composition’s function

Tricalcium Silicate (C₃S)

contributes to early strength and first set by quickly hydrating and hardening. increased early strength is the result of increased C₃S percentages.

Di-calcium Silicate (C₂S)

gradually hardens and hydrates, primarily aiding in the development of strength after a week.

Tricalcium Aluminate (C₂A)

releases a lot of heat in the first few days of hydration, which helps with early strength a little bit. The addition of gypsum to cement reduces the pace at which C₃A hydrates. Particularly resilient to sulfate-containing soils and waterways are cements with low C₃A content.

Tetracalcium aluminoferrite (C₄AF)

has no appreciable impact on hydration.