Accelerating cement hydration with C-S-H seeds

摘要

The acceleration of cement hydration through synthetic C-S-H shows great potential for increasing the early strength of cementitious systems. The selection of a suitable calcium-to-silicon ratio and optimized synthesis conditions result in a significant strength gain compared to non-optimized systems. Polymers may contribute during synthesis to stabilizing the C-S-H aggregates and enhancing the storage stability of the suspensions. Compared to conventional accelerators, C-S-H was not observed to be corrosive, nor did it compromise the long-term strength when used in suitable concentrations. Through the application of non-toxic calcium silicate hydrate as aqueous suspension, a very positive benefit-risk ratio of the accelerator was confirmed [45]. A final advantage of C-S-H seeding is that effective seeds can be prepared from cheap starting materials like lime and silica in a facile pozzo-lanic synthesis, as confirmed by Land et al. [41].