摘要
采用不同掺量的石灰石粉取代水泥配制混凝土,同时配制复掺6%偏高岭土和20%石灰石粉的混凝土,并采用相同的胶凝材料体系制备水泥净浆,开展Na_2SO_4溶液浸泡试验。测试了混凝土抗压强度,采用RCM法和硫酸盐干湿循环侵蚀试验分别测试混凝土的氯离子扩散系数和抗硫酸盐侵蚀性,采用MIP法测试混凝土孔结构,进一步采用SEM观察浸泡后净浆试件的微观形貌。结果表明,石灰石粉对混凝土抗压强度、抗氯离子渗透性和抗硫酸盐侵蚀性均有一定的不良影响。采用偏高岭土与石灰石粉复掺可以有效提高掺偏高岭土混凝土的强度、抗氯离子渗透性和抗硫酸盐侵蚀性。其机理主要在于优化了混凝土孔结构,降低了有害离子在混凝土中的传输速度,阻止了混凝土在硫酸盐环境中钙钒石、石膏等侵蚀产物的形成。
Concretes were prepared with cement solely substituted by different dosages of limestone powder （LsP） and double substituted by 6% metakaolin （MK） and 20% LsP. Pastes were prepared with the same cementitious materials of concretes and immersed in sulfate solution for a long time. Concrete compressive strength were tested, as well as the chloride diffusion coefficient and sulfate resistance. Pore structure of concretes and morphology of pastes were tested by MIP and SEM respectively. The exper imental results reveal that concrete compressive strength,chloride resistance and sulfate resistance are decreased by LsP. MK sig- nificantly improves the compressive strength, chloride resistance and sulfate resistance of the LsP concrete. The improvement mechanism of the above performances is that MK can improve the pore structure and hydrates composition of concrete, decrease the transmission of corrosion ions and prevent the formation of ettringite and gypsum.
出处
《武汉理工大学学报》
CAS
北大核心
2016年第5期28-33,共6页
Journal of Wuhan University of Technology
基金
广州市科技计划项目珠江科技新星专项(2016100110153)
关键词
石灰石粉
偏高岭土
抗压强度
氯离子扩散系数
硫酸盐侵蚀
limestone powder
metakaolin
compressive strength
chloride diffusion coefficient
sulfate corrosion
