Influence of recycled aggregates and silica fume on the performance of pervious concrete

Abstract

A large amount of waste is produced daily, across cities worldwide. To ensure that this waste is not discarded incorrectly and does not pollute the environment or occupy areas for other purposes, we must find ways to reuse it. This work proposes the evaluation of pervious concrete with construction and demolition waste from a recycling plant. It is a proposal that unites the use of construction waste with the positive contribution of pervious concrete that allows rainwater to infiltrate it. To determine the appropriate mix for high-strength pervious concretes, pervious concrete with a superplasticizer additive, 10 % silica fume, natural aggregate, and replacing natural aggregates with 40 %, 50 %, and 60 % recycled aggregates were analyzed. The following tests were performed: absorption, void ratio, permeability, compressive strength, flexural tensile strength, thermal analysis, X-ray diffraction, and scanning electron microscopy. The performance of the material was evaluated by building an experimental track with pervious concrete made of natural aggregates and replacing natural aggregates with 40 % and 60 % recycled aggregates. With an increase in natural aggregates from 40 % to 60 % in pervious concrete, a reduction in the compressive strength was observed compared to the control. Pervious concrete with 40 % recycled aggregates presented the best results for the properties analyzed. Further, all samples presented values higher than those established in the ABNT NBR 16416/2015 standard for use in pervious concrete in pedestrian traffic areas.