EFFECT OF C-S-H COEXITENCE ON THE FORMATION OF ETTRINGITE FROM MONOCARBONATE

Abstract

This study aimed to understand the effect of C-S-H coexistence on the formation of ettringite from monocarbonate. The results indicated that ettringite formation from monocarbonate may be enhanced when C-S-H coexists with monocarbonate. This was thought to be because when C-S-H coexists with monocarbonate, the dissolution of monocarbonate is promoted to form C-A-S-H. It was also shown that 4-coordinate Al in C-A-S-H can be used for ettringite formation, especially 4-coordinate Al substituted at Q²_b （bridging-site） of C-A-S-H may be preferentially used for ettringite formation.