纳米二氧化硅对硅酸盐水泥水化硬化的影响_徐迅.pdf

· 478 · 2007 35 4 Vol. 35 No. 4 2 0 0 7 4 JOURNAL OF THE CHINESE CERAMIC SOCIETY April 2007 (, 621010) X SiO SiO 2 2 5% () Ca(OH) 2 SiO2 TQ172 A 0454–5648(2007)04–0478–07 EFFECT OF NANO-SILICON DIOXIDE ON HYDRATION AND HARDENING OF PORTLAND CEMENT XU Xun LU Zhongyuan (School of Material Science and Engineering, Southwest University of Science and Technology, Key Laboratory for Building Materials of Sichuan Province, Mianyang 621010, Sichuan, China) Abstract: The hydration and hardening of cement-based materials containing nano-silicon dioxide of 5% (in mass) were investigated by microcalorimeter, X-ray diffraction, differential thermal analysis, scanning electron microscope, and nitrogen adsorption. The results show that nano-silicon dioxide can consume large amounts of Ca(OH)2 due to its high pozzolanic activity, so that hydration can be accelerated, the evolution rate of hydration heat in the early period can be increased, the microstructure can be improved and harden cement paste gets more homogeneous and dense. Nano-silicon dioxide can increase water requirement of normal consistency, shorten setting time and enhance com- pressive strength of cement-based materials, especially at middle period and later period. Key words: nano-silicon dioxide; silica fume; portland cement; hydration; hardening SiO2 [1–3] SiO2 [7–8]SiO2