Portland Cement Clinker - an overview | ScienceDirect Topics
Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates (3CaO.SiO 2 and 2CaO.SiO 2), the remainder consisting of aluminium and iron containing clinker phases and other compounds.The ratio of CaO to SiO 2 shall not be less than 2.0. The magnesium oxide content (MgO) shall not exceed 5.0% by mass.