Recycled aggregate pervious concrete: Analysis of influence of water-cement ratio and fly ash under single action and optimal design of mix proportion

Abstract

Pervious concrete is recommended, which is of great benefit to the ecological environment and human living environment. In this paper, the influences of five water-cement ratios and four fly ash contents to replace the cement by mass with a water-cement ratio of 0.30 on the properties of Recycled Aggregate Pervious Concrete (RAPC) were studied. Following this, based on the Grey relational-Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) optimization method, the strength, permeability, abrasion loss rate, and material costs of RAPC were adopted as evaluation indices to establish a mix proportion optimization model. The results show that the increase of water-cement ratio and fly ash replacement level of RAPC leads to decreased compres-sive strength while an increase in the permeability and abrasion loss rate. According to test results based on the optimal model 0.30 was identified as the best mix proportion. In addition, ecological-economic analysis of RAPC raw materials was carried out by comparing different natural aggregates. The results of EE (embodied energy) and ECO2e (embodied CO2 emission) pointed out that the combination of recycled aggregate and fly ash leads to significant ecological and economic benefits.