纳米SiO2改性再生混凝土抗氯离子的渗透性能实验

Experimental study on chlorine ion penetation resistance of nano-SiO2 modified recycled concrete

为了得到纳米SiO 2溶液改性再生骨料的最佳处理方式及改性处理后再生混凝土的抗氯离子渗透性能,采用3组不同浓度(2%、4%、6%)纳米SiO 2溶液、浸渍时间不同(24、36、48、60和72 h)的方式对再生骨料进行改性处理.通过NEL法研究SiO 2溶液改性后再生骨料不同取代率(50%、70%、100%)的再生混凝土氯离子扩散系数,并与未经改性处理的取代率为100%的再生混凝土比较.结果表明:通过纳米SiO 2溶液改性处理后的再生混凝土强度和抗氯离子渗透性能比未经改性处理的再生混凝土有较大提升,质量浓度4%浸渍36 h时处理效果最为显著.

In order to obtain the best treatment method of recycled aggregate modified by nano-SiO 2 solution and the resistance to chloride ion permeation of recycled concrete after modification,three groups of different concentrations of SiO 2 solution were used(2%,4%,6%).The regenerated aggregate was modified with different impregnation time of 24,36,48,60 h.The chloride diffusion coefficient of recycled concrete with different substitution rate(0%,50%,70%,100%)was studied by NEL method.The results were compared with recycled concrete with 100%substitution rate without modification.The results show that:the strength and chloride penetration resistance of recycled concrete treated with nano-SiO 2 solution were much higher than that of unmodified recycled concrete,and the treatment effect was most remarkable when the mass concentration was 4%impregnated for 36 h.