纳米SiO2浸泡改性再生橡胶混凝土力学性能研究

本实验主要目的是研究经过纳米SiO2溶液浸泡的再生骨料橡胶混凝土坍落度、抗压强度和劈裂强度的变化规律、确定此操作对再生骨料混凝土的影响。实验以C30素混凝土为基准，通过掺入5%(等质量取代砂)的橡胶颗粒、纳米SiO2溶液（0%、1%、3%，相对水的质量）和再生骨料（Recycled concrete aggregate, RCA）（30%、50%、100%，等质量取代天然骨料），制备纳米SiO2改性再生橡胶混凝土试件并进行坍落度、抗压和抗劈裂试验，分析不同浓度的纳米SiO2溶液和不同RCA取代率对再生橡胶混凝土力学性能的影响。结果显示：控制其他变量相同的RCA混凝土试块中，纳米SiO2溶液浓度的增加会降低拌合物的坍落度，而RCA取代率的增加会提高拌合物的坍落度；在30%RCA取代率和1%浓度的纳米SiO2溶液时再生橡胶混凝土的抗压强度和劈裂抗拉强度比基准组分别高出2.5%和6.7%；总体来看，经过纳米SiO2溶液浸泡后的再生橡胶混凝土呈现出早期强度和后期强度提升的特点。

Study on mechanical properties of recycled rubber concrete modified by nano-SiO2 immersion

The main purpose of this experiment is to study the variation law of slump, compressive strength and splitting strength of recycled aggregate rubber concrete soaked in nano-SiO2 solution, and to determine the impact of this operation on recycled aggregate concrete. Based on C30 plain concrete, nano-SiO2 modified recycled rubber concrete specimens were prepared and tested for slump, compression and splitting resistance by adding 5% (equivalent mass instead of sand), nano-SiO2 solution (0%, 1%, 3%, relative water mass) and recycled concrete aggregate (RCA) (30%, 50%, 100%, equivalent mass instead of natural aggregate), The effects of different concentrations of nano-SiO2 solution and different RCA substitution rates on the mechanical properties of recycled rubber concrete were analyzed. The results show that in RCA concrete test blocks with the same control of other variables, the increase of nano-SiO2 solution concentration will reduce the slump of the mixture, while the increase of RCA substitution rate will increase the slump of the mixture; At 30% RCA substitution rate and 1% concentration of nano-SiO2 solution, the compressive strength and splitting tensile strength of recycled rubber concrete are 2.5% and 6.7% higher than those of the reference group respectively; In general, RCA rubber concrete soaked in nano-SiO2 solution shows the characteristics of early strength and late strength improvement.