Effect of nano C-S-H on early hydration and strength of cement with different mineral admixture
Nano-calcium silicate hydrate has been studied by many researchers because it can greatly promote the hydration rate of cement in the early age.But the most studies are focused on pure cement,and there are few researches on its application in composite cementitious material system.The effects of nano-calcium silicate hydrate on the early hydration process and strength development of cement containing fly ash and granulated blast furnace slag were studied by isothermal calorimetry test,X-Ray diffraction test(XRD),electrical conductivity,mercury intrusion porosimetry(MIP)and compressive strength test.The results show that the nano-calcium silicate hydrate has obvious accelerating effect on the early hydration process of cement,especially before 12 hours.Then the accelerating effect becomes insignificant after 24 hours.The positive effect of nano-calcium silicate on cement is mainly due to the promoting effect on reaction of C3S and C3A minerals before 1 day,then the reaction rate of C3S decreased after 3 days and its content is higher than that of the comparison sample.At the early stage of hydration,the compressive strength increases more than doubled because of promoting effect of nano-calcium silicate hydrate and there is no obvious effect on compressive strength of cement in later age.
万方数据
维普
