Influence of Wastewater Content on Mechanical Properties, Microstructure, and Durability of Concrete

In this study, high concentration wastewater from ready-mixed concrete plants was used to replace potable water as mixing of concrete, with replacement rates 0%, 25%, 50%, 75%, and 100%, by weight. The solid content the 12%. Five groups C20 mix proportions were designed. Different properties, including workability, compressive strength durability under freeze–thaw cycles, carbonization, drying conditions, studied, effect increase in proportion a for investigated. microstructural attributes developed studied through X-ray diffraction (XRD), thermal analysis (TG-DSC), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), mercury intrusion porosimetry (MIP). Finally, economic benefits replacing analyzed. results indicate that using reduces workability superplasticizer is needed ensure adequate workability. At ages 7, 28, 56 days, (0, 100%), shows trend first decreasing, then increasing, decreasing. When highest. microstructure showed main products wastewater-mixed are calcite (CaCO3), portlandite (Ca(OH)2), ettringite (Aft), calcium silicate hydrate (C-S-H). Adding does not lead formation new concrete. Wastewater can fill pores well, thus optimizing pore structure. has densest microstructure, lower porosity, better Durability properties further 75% improve concrete’s frost resistance. However, there negative impact on carbonation resistance wastewater. weight shrinkage recycling only green environmentally friendly but also good environmental benefits.