基于欧洲标准研究内部硫酸盐反应对混凝土体积稳定性的影响

摘要

基于欧洲标准并采用残余膨胀试验和SEM测试方法,通过胶凝材料体系的组成差异,研究了内部硫酸盐反应对混凝土体积稳定性的影响并分析了其机理.结果表明:内部硫酸盐反应对混凝土体积稳定性存在影响,而胶凝体系中C3A越多,能与体系或渗入的硫酸盐反应生成AFt和AFm就越多,内部硫酸盐反应将更剧烈;AFt水化产物主要在混凝土孔隙中生成并生长;而AFm主要与CSH凝胶胶结生成;而内部硫酸盐反应使混凝土产生体积膨胀,主要是AFm转化为AFt时体积膨胀所致.%Based on European standard and the residual swelling test and SEM test method,through the composition differ-ence of gelled material system,the influence of internal sulfate reaction on volume stability of concrete was studied and its mech-anism was also analyzed. The results show that the internal sulfate reaction have influence on the stability of concrete volume,and the more C3A in the gel system,the more AFt and AFm can be generated,and its internal sulfate reaction more intense;AFt hy-dration products mainly generated in concrete pore and grew;and AFm main generated by bonding with CSH gel;while internal concrete sulfate reaction will produce volume expansion,which mainly caused by AFm expands when it is converted into the AFt.