Hydration and microstructure of tricalcium silicate incorporating nano-TiO2

In order to clarify the enhancing mechanism of nano-TiO 2 (NT) on tricalcium silicate (C 3 S) paste, the hydration and microstructure of C 3 S with and without NT were investigated. Hydration properties were analyzed by setting time, compressive strength , hydration heat, Ca(OH) 2 content and relative content of C-S-H. Moreover, the microstructure of C 3 S paste was studied by pore structure and micromorphology. The results showed that seeding effect of NT promoted the chemical activity as well as hydration of C 3 S and more NT led to higher hydration degree. Besides, NT can increase the content of Ca(OH) 2 and the relative content of C-S-H, which also proved the enhancement effect of NT on C 3 S chemical activity and hydration. Furthermore, the seeding effect and filling effect of NT decreased total porosity, enhanced density and meliorated the microstructure of hardened C 3 S paste. Ultimately, the improved hydration and optimized microstructure introduced by NT enhanced the compressive strength of C 3 S paste.