Non-efflorescent hydraulic cement prepn

NOVELTY - A non-efflorescing cementitious body comprises a source of calcium aluminate, a source of calcium silicate, a source of sulfate and a source of reactive silica. The ingredients are present in proportions that, upon hydration, ettringite and hydrated alumina are present in the body. USE - For coating on concrete article, e.g. roofing tiles, plates, cladding and walls (claimed). ADVANTAGE - The invention achieves reduced efflorescence, while maintaining very good dimensional stability with very low leach rate and very good acid resistance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (A) a method of forming a non-efflorescing cementitious body comprising curing aqueous composition; and (B) a hydraulic binder/aqueous paste for forming a non-efflorescing cementitious body.