Hydration of calcium chlorosilicate Ca 3SiO 4Cl 2

• Published in: Cement and concrete research Vol. 15; no. 5; pp. 785 - 792
• Main Authors: Kurdowski, Wieslaw, Miskiewicz, Krzysztof
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1985
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/0008-8846(85)90144-9

The investigations of the hydration of the calcium chlorosilicate have shown that this phase dissolves congruently. However, unlike in the case of calcium orthosilicate, a high content of silica is retained in the solution. The dissolution process proceeds at first rather slowly and after 60 minutes its rate becomes considerably increased. On the calorimetric curve this corresponds to a short induction period. After 2 hours the hydrates are already detectable by X-ray examination. They are for H 2O/dry sample = 10, CSH and CH, and for H 2O/dry sample ratio = 1, CSH, CaCl 2CHH and CH. An addition of the SiO 2 gel or CSH phase considerably accelerates the process, reducing simultaneously the induction period. Under these conditions the hydrates are detectable by X-ray examination after 1 hour. It is probable that the induction period occuring in the hydration of chlorosilicate is due to the nucleation of the CSH phase.