Research on the frost resistance performance of fully recycled pervious concrete reinforced with fly ash and basalt fiber

Abstract

In this paper, fly ash (FA) and basalt fiber (BF) were considered to solve the poor frost resistance in recycled pervious concrete (RAPC) prepared with 100 % recycled concrete aggregates (RCA), and the optimal FA replacement rate for cement and BF content were researched. The results indicate that partial replacement cement by FA not only improved the strength of RAPC but also enhanced its frost resistance. The addition of BF further improved the frost resistance of RAPC and enhanced its overall integrity after freeze-thaw cycles. When the replacement rate of FA is 6 % and the content of BF is 4 kg/m3, the maximum compressive strength of RAPC is 24.3 MPa. When the FA replacement rate was 6 % and the BF content was 6 kg/m3, the specimens exhibited a minimum loss of mass is 0.9 % after 100 freeze-thaw cycles, the highest relative dynamic modulus of elasticity (RDME) was 62.5 %, and the minimum damage variable was 34.4 %. Besides, a quadratic function that could effectively predict the relationship between freeze-thaw damage of RAPC and the number of freeze-thaw cycles was established. The use of FA can not only reduce the amount of cement, but also improve the mechanical properties and frost resistance of RAPC. The addition of BF can further improve the integrity of RAPC after freeze-thaw cycles.