Study on Performance of Pervious Concrete Modified by Nano-Silicon + Polypropylene Fiber Composite

Abstract

In order to improve the comprehensive performance of pervious concrete, nano-silicon and polypropylene fiber were added to pervious concrete to study the change of performance of pervious concrete. Firstly, the effect of single doped nano-silicon on the properties of cement slurry and pervious concrete was studied, and the optimal water-binder ratio and nano-silicon content were determined. Based on this, mixed polypropylene fiber with different proportions of length of 18 mm to determine the reasonable amount of polypropylene fiber. The results showed that the compressive strength of pervious concrete was the highest when the nano-silicon content was 0.5% and the water-binder ratio was 0.32. Based on this ratio, the maximum compressive strength can be obtained by adding 1.0 kg/m3 polypropylene fiber, and the compressive strength of 7d and 28d increased by 29.9% and 42.2%, respectively. Adding 1.5 kg/m3 polypropylene fiber was the most beneficial to improve the freezing resistance of pervious concrete. For example, after 300 freeze–thaw cycles, the compressive strength residual rate was 62%. That's much higher than the 40 percent that was found when nano silicon was mixed alone.