Appear as lumps or nodules, usually 3 millimetres (0.12 in) to 25 millimetres (0.98 in) in diameter, produced by sintering (fused together without melting to the point of liquefaction) limestone and alumino-silicate materials such as clay during the cement kiln stage.
Common type of powdery cementitious building material made from finely pulverized alumina, iron oxide, lime, magnesia, and silica burnt together in a kiln.
Portland cement type 1 is usually used in conditions that have low sulfate such as the General construction of most buildings, bridges, pavements, precast units, etc
Portland cement type 2 is usually used in places where there is water underground or a high percentage of sulfate and so is designed to be resistant to sulfate attack because the sulfate creates stresses which force the concrete to expand and crack.
Portland cement type 5 is usually used for building dams, bridges and underground constructions because of its low heat of hydration and extremely high resistance. It is not recommended for making reinforced concrete because of chemical chlorine attacks.