Performance of concrete with treated wastewater and recycled aggregates

Water scarcity is a problem that currently affects a large part of the world's population. The manufacture of concrete involves the consumption of large quantities of drinking water, as well as a high consumption of natural resources used as raw materials in its manufacture. Solutions need to be found to mitigate the environmental impact caused by the manufacture of this material. In this study, the use of two types of treated wastewater (TWw) at application ratios of 0 %, 50 % and 100 % was evaluated as an alternative to the use of drinking water (DW) in the production of concrete. At the same time, the substitution of natural aggregates with 50 % recycled aggregates (RA) was also studied. To test the possible use of TWw and RA in concrete production, the mechanical and durability properties were evaluated. It was found that the partial or total use of TWw that fulfilled some given chemical properties requirements in the manufacture of concrete did not influence the final mechanical and durability properties. The combination of TWw and RA in concrete manufacturing resulted in similar properties to those of concrete manufactured with DW and RA for 50 % TWw application values. However, the combined use of TWw and RA at high substitution ratios led to a deterioration of concrete durability, increased absorption and carbonation depth.