Cement is a binder, a substance that sets and hardens independently, and can bind other materials together. It’s about a blend of calcium silicates and calcium aluminates, obtained by high temperature firing of limestone and clay or marl (in this case we speak about natural cements).
There are different types of cement, classified in composition, strenght and hardness and thus for the intended use.
As per UNI EN 197-1 regulation, cements basic requirements are:
Composition: Portland cement is the basis of almost all kinds of cement presently used in building industry. From Portland cement blended with different materials in variable proportions but in compliance with above mentioned regulation, all other types and subtypes of cement can be obtained.
Normalized resistance class (in 28 days) expressed in Pa M with reference to the initial compressive strength (7 days for 32, 5N and 2 days for other classes).The concrete strength class depends on the fineness of grinding of the same and the percentage of tricalcium silicate compared to dicalcium. For each normalized resistance class can be defined two classes of initial resistance N (ordinary) and R (high resistance).
UNI EN 197-1 regulation defines 5 types of cement, 27 subtypes and 6 resistance class.
