掺石灰石粉混凝土的性能及其改善途径

发布时间：2018-04-23 20:19

本文选题：石灰石粉 + 偏高岭土　；参考：《武汉理工大学学报》2016年05期

【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。
[Abstract]:The concrete was prepared with different amount of limestone powder instead of cement, and the concrete with 6% metakaolin and 20% limestone powder was prepared at the same time. The cement paste was prepared with the same cementing material system, and the soaking test of Na_2SO_4 solution was carried out. The compressive strength of concrete was tested, the chloride diffusion coefficient and sulfate corrosion resistance of concrete were tested by RCM method and sulfate dry and wet cycle erosion test, and the pore structure of concrete was tested by MIP method. SEM was used to observe the microstructure of the sample after soaking. The results show that limestone powder has some negative effects on the compressive strength, chloride ion permeability and sulfate corrosion resistance of concrete. The addition of metakaolin and limestone powder can effectively improve the strength, chloride ion permeability and sulfate corrosion resistance of concrete mixed with metakaolin. The main mechanism is to optimize the pore structure of concrete, reduce the transfer speed of harmful ions in concrete, and prevent the formation of erosion products such as calcium vanadium and gypsum in the sulfate environment of concrete.
【作者单位】：交通运输部水工构造物耐久性技术交通行业重点实验室;中交四航工程研究院有限公司;
【基金】：广州市科技计划项目珠江科技新星专项(2016100110153)
【分类号】：TU528

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