The hydration of cements with various mineral composition and their microstructure formation in mortar were investigated. And the strength development of low W/C mortar was discussed form these factors. Analyses on the hydration degree of cement, composition of hydrate and pore structure of hardened mortar suggest followings ;
The belite rich cement forms more C-S-H and less Ca (OH) 2 than the other cements. It is considered that the C-S-H hardly fills the large pores remained in early age, though the large Ca (OH) 2 fills them efficiently. It is also considered that the relatively small pores in later age are filled by the small increase of C-S-H. Therefore, the belite rich cement develops the relatively uniform hydrated layer composed mainly of C-S-H. It is the reasons why the belite rich cement shows the remarkable strength development in later age.
