Effect of major compositional variation

The ability of a substance to act as a hydraulic cement depends on two groups of factors. First, it must react with water to a sufficient extent and at a sufficient rate y-CjS, which is virtually inert at ordinary temperatures, has no cementing ability. Second, assuming that an appropriate ratio of water to cement is used, the reaction must yield solid products of very low solubility and with a microstructure that gives rise to the requisite mechanical strength, volume stability, and other necessary properties. CjA reacts rapidly and completely with water, but the products that are formed when 

Other hypotheses based on considerations of crystal structure have been proposed, and in varying degrees may account for second-order effects. Thus, Jeffery (Jl) suggested that irregular eoordination of caleium was responsible for the high reaetivity of C3S as eompared with Y-C2S however, lime reacts with water, but the coordination of its calcium atoms is highly 

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