纳米SiO2对混凝土盐类结晶循环性能的影响

为了改善混凝土在海水、土壤等盐环境中的性能,通过混凝土强度试验,研究了掺纳米SiO2混凝土在盐类结晶循环中的性能,并通过扫描电子显微镜（SEM）和X-射线衍射分析（XRD）对混凝土微观结构进行了研究.结果表明：纳米SiO2能够改善混凝土的性能;从性能和经济两方面考虑,推荐纳米SiO2的最佳掺量（质量分数）为1%.与基准混凝土相比,在110次循环后,掺纳米SiO21%的混凝土的耐腐蚀循环系数和相对耐腐蚀循环系数分别提高11%和20%.微观结构分析表明,纳米SiO2可以改善混凝土界面结构,降低氢氧化钙的含量.

Effect of Nano-SiO2 on Performance of Concrete in Dissolving/Crystalling Cycles of Salts

To improve the performances of concrete in sea water or soil with inorganic salts,the performance of concrete with nano-SiO2 in dissolving/crystalling cycle of salts was investigated by the experiment of concrete strength,and the microstructure of concrete was analyzed with SEM(scanning electron microscope) and XRD(X-ray diffraction).The result shows that nano-SiO2 can improve the performances of concrete.By considering the performance of concrete and its construction cost,the optimum mass fraction of nano-SiO2 is 1%.Compared with normal concrete,modulus ratio and special modulus ratio of the concrete with 1%(mass fraction) nano-SiO2 in dissolving/crystalling cycle of salts increase by respectively 11% and 20% after 110 cycles.The analysis of the microstructure shows that nano-SiO2 can improve interface structure between cement and aggregate,and decrease the content of Ca(OH)2 in concrete.