Effect of Wastewater on Concrete Curing and Mixing

Concrete is a crucial material in construction projects, requiring significant amounts of water for mixing and curing. However, the use of freshwater in construction contributes to the depletion of this vital resource, posing a challenge for future generations. To address this issue, wastewater can be utilized as a substitute for freshwater in concrete production. This study investigates the feasibility of using river mix wastewater. The concrete mix was designed with replacing potable water with the river mix wastewater. Five proportions were designed to study the effect of wastewater on concrete strength for mixing with 0, 25, 50, 75 and 100%. Results exhibit that the compressive strength of mix has been found to be increasing from 40.5 (0%) to 43 MPa (75%). Similarly, split tensile strength was observed correspondingly as 3.14 (0%) to 3.21 MPa (50%). On the contrary, some improvement was observed in strength parameters when wastewater was used for curing alone with 100% replacement of potable water. This was reasoned by the high amount of Total Dissolved Solids (TDS) presence in wastewater used. However, beyond a certain threshold, further increases in TDS content leads to a decrease in strength (Bahraq et al. 2020). This phenomenon is attributed to the initial filling of voids by dissolved solids, followed by the presence of excessive solids causing instability and strength reduction. Replacing portable water with wastewater in concrete production has shown to enhance mechanical strengths. Our approach not only conserves freshwater resources but also utilizes wastewater effectively, contributing to sustainable construction practices.