ABSTRACT
Portland cements are inorganic binders obtained by grinding to a high fineness Portland clinker alone, or - most commonly - in combination with calcium sulfate, acting as a set regulator. The ASTM standard C219-94 defines Portland cement as "a hydraulic cement produced by pulverizing Portland-cement clinker, and usually containing calcium sulfate." The European standard ENV197-1 requires for Portland cement a clinker content of 95 100% and a content of "minor additional constituents" of no more than 5%, in addition to limited amounts of calcium sulfate.
