Amorphous systems hydration limit

If mixed with water, the existing calcium hydroxide, or that formed in the hydration of added lime, dissolves in the liquid phase and reacts with the glass phase of the ash. An amorphous C-S-(A)-H phase is formed as the product of reaction, which—at appropriate water/solid ratios of the starting mix—causes setting and hardening of the system. Limited amounts of ettringite (AFt) and monosulfate (AFm) may also be formed in the reaction, if sulfate ions are present in the ash. 

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