STUDIES ON SYNTHESIS OF C-S-H BY DOUBLE COMPOSITION METHOD WITH CALCIUM CHLORIDE, AND RECYCLE SYSTEM

Abstract

This paper describes the investigations of the possibility of the recycled cement. Amorphous C-S-H with a high Ca/Si ratio was synthesized by the double-decomposition method using CaCl₂ and Na₄SiO₄ mainly. We analyzed the hydration reaction mechanisms and hydrated products for the highly reactive β-C₂S. Also, hydrated products were heated again to generate β-C₂S in the second cycle. As a result, when β-C₂S with high NaCl contents was hydrated, C-S-H with a high Ca/Si that CH did not coexist was confirmed even at room temperature 20℃. Also, the generated C-S-H had the same properties as the starting synthetic C-S-H. Furthermore, the highly reactive β-C₂S is generated again by reheating the hydrated products.