ABSTRACT
Improving the self-healing properties of concrete is of great significance for extending the service life of buildings and avoiding catastrophic accidents. In this paper, concrete samples with doping amounts of 1%, 1.5% and 2% were prepared by incorporating nano-silica dioxide (SiO2) reactive powder, and the influence of nano SiO2 content on concrete self-healing properties were explored. Experimental results show that the nano SiO2 can effectively improve the ultimate compressive strength and splitting strength of concrete. Meanwhile, the nano SiO2 improves the recovery rate of the compressive and splitting strength of the preloaded concrete, and there exists the optimal nano SiO2 content for the maximum recovery rate of the concrete compressive strength and the splitting strength. In addition, experiments found that the strength recovery rate of concrete decreases with the increase of the preload, which results in decreasing recovery rate of compressive strength and splitting strength. These test results can provide guidance for optimizing the self-healing properties of concrete.
