Dispersion characteristics of various contents of nano-TiO_2 and its effect on the properties of cement-based composite

摘要

Effect of nano-TiO2 on the compressive strength and permeability of cement paste was studied, and the mechanism was revealed through investigating the hydration evolution and hydration products distribution of cement containing various contents of nano-TiO2. Hydration Heat of cement, microstructure and pore structure of cement paste indicated that nano-TiO2 could act as nuclear to accelerate the cement hydration, and this acceleration effect strengthened upon the nano-TiO2 content at early age while reversed at long age. Distribution uniformity of nano-TiO2 and hydration products was characterized and quantitative evaluated based on the method of energy dispersive X-ray spectroscopy, which showed that the dispersion of nano-TiO2 and hydration products had a high relativity, and the most uniform distribution was achieved at a small content of nano-TiO2. The main effect of nano-TiO2 on the properties of cement paste at early age and long age was the accelerated hydration and the improved distribution uniformity, respectively.