摘要
用模拟化学反应的方法研究碱-硅集料反应的过程机理。确定数量的无定形SiO_2在典型浓度的碱溶液中溶解可能导致最高SiO_2浓度的溶液,这同时也是SiO_2/Na_2O摩尔比最高的溶胶,它的溶胶粒子数量最多、比表面积最大,而SiO_2的聚合度却相当低(<12)。在混凝土中存在的各种电解质及固体氢氧化钙的化学作用下,这种溶胶可以转化为凝胶。
The mechanism of alkalis-silica reaction has been studied in the laboratory, using a chemical reaction model. The dissolution of a certain quantity of amorphous silica in a typical concentration alkali solution could lead not only to the greatest solubility of SiO_2 in the solution, but also to a sol with maximum SiO_2/Na_2O molar ratio, R_(?). This maximum R_(?) solution is composed of the largest number of colloidal particles with the largest specific surface area; while their polymerization degree of SiO_2 is relatively low(<12).This sol can be solidified(gelated or coagulated)by the chemical action of electrolytes, e.g.NaCl, KCl, CaSO_4·0.5H_2O,CaSO_4·2H_2O, etc, and solid Ca(OH)_2(portlandite), which exist ordinarily in concrete.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1991年第2期97-103,共7页
Journal of The Chinese Ceramic Society
关键词
碱
硅
集料反应
溶胶
凝胶
alkali-aggregate reaction
formation of sols
transformation into gels
