Essay On Portland Cement

3. Types of cement: Portland cement:

The Romans were probably the first people who made hydraulic binders which will harden underwater by mixing lime with volcanic material. In 1824, an English man called Joseph Aspdin discovered the Portland cement by mixing limestone with clay. 1 According to ASTM C 150, Portland cement is defined as “hydraulic cement produced by pulverizing clinker consisting essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an interground addition.” 3

It exist five types of Portland cement 7:

Type I: “regular cement” 7 used in general construction when specialized properties are not required;

Type II: “modified cement” 7 used in structures exposed water containing sulfate ions where a moderated sulfate

Type V: “High sulfate resistance Portland cement” 7 used when the structures are exposed to a high concentration of sulfate ions, where is preferred to have high sulfate resistance.

The different types of Portland cement contain around 75 % of calcium silicate. The type II and V have a lower content of C3A, less than 8 % for type II and less than 5 % for type V. the type III has a higher percentage of C3S and a higher fineness, the fineness and percentage of C3S are directly related to the early strength development. Type IV releases heat and gains strength more slowly; this is due to its low content of C3S.

White cement:

The white color is obtained by using very pure raw materials freed from all traces of iron oxide. It has similar characteristics to those of Portland cement. Pigments can be added to this cement which allows the producing of different cement with various colors. The white cement is used for decorative application.1

High alumina