Cement is a fine binder powder with binding properties that hardens on contact with water. In addition of water, cement becomes a homogeneous paste. Cement is capable of hardening and preserving its structure, even in spite of a new contact with water. The most used is called Portland cement.
Portland cement can be defined as a hydraulic. Is produced by pulverizing clinker; is composed of hydraulic calcium silicates. Generally cement, contain one or more of the forms of calcium sulfate as an addiction during grinding.
We will identify 5 different categories of Portland cement each with its specific physical and chemical characteristics.
The normal cement, the one we all know, used in the construction of concrete works in general structures. The cement type I cement is used when the specifications do not indicate another type. This cement type releases more hydration heat than other types of cement.
Has a medium resistance to sulfate attacks. Is used in construction works in general. Is used in constructions exposed to the moderate action of sulfate, or that require a moderate heat of hydration. Also, when so stated in the construction specifications.
The maximum amount of tri calcium silicate and tri calcium aluminate are regulated. In general is the cement used in the realization of concrete pipes and bridges.
This type of cement one develops a high resistance in a minor time. Just in 7 days cement type III has the same resistance that a concrete type I or II in 28 days. In order to achieve this fast setting, the amounts of tri calcium silicate and tri calcium aluminate are increased.
This cement gives off large amounts of heat so it is not recommended for massive blasting. Cement type III is used for example for the construction of prefabricated elements or emergency constructions.
Type IV is a cement of slow drying. For this reason cement type IV does not generate great amount of hydration heat being ideal for massive blasting that do not require a high initial resistance. To achieve this, the amounts of tri calcium silicate and tri calcium aluminate are regulated.
Cement type IV is used in very large concrete structures, such as dikes.
This cement is used in the construction of elements that need a high resistance to the concentrated attack of sulfates and alkalis. To achieve this, the amount of tri calcium aluminate is reduced as this is the most vulnerable component to sulfates.
Cement type V is used, for example, in the construction of sewers, conduction channels and port infrastructures.