Influence of CSH grown in situ on steel slag powder on the performance of fresh and hardened cement pastes

In this paper, for improving the enhancement efficiency of synthetic CSH to cement pastes, it was grown in situ on steel slag powder by a chemical co-precipitation reaction. Compared with common CSH, in situ-grown CSH had less negative influence on the workability of fresh cement pastes. More importantly, it also had a more prominent accelerating effect to cement hydration, which raised the hydration rate and increased the chemically bonded water content. Therefore, it promoted the strength development of cement pastes more efficiently and heightened the early and long-term strength of hardened cement pastes more distinctly. Besides, it refined the pores in the hardened cement pastes, decreasing the porosity more remarkably. Consequently, it can be believed that in situ-grown CSH has more outstanding seeding and filling effects due to its improved dispersibility, so as to enhance the performance of cement pastes more efficiently.