Mechanical, Durability, and Microstructural Evaluation of Coal Ash Incorporated Recycled Aggregate Concrete: An Application of Waste Effluents for Sustainable Construction

Abstract

This study has endeavored to produce eco-friendly coal ash-incorporated recycled aggregate concrete (FRAC) by utilizing wastewater effluents for environmental sustainability. The mechanical and durability efficiency of the FRAC manufactured were explored using different kinds of effluent by performing a series of tests at various ages. The considered kinds of effluent for the mixing of FRAC were collected from a service station, as well as fertilizer, textile, leather, and sugar factories. Scanning electron microscopy (SEM) was utilized to judge the microstructural behavior of the constructed concrete compositions. The outcomes revealed that using textile factory effluent in the manufacturing of FRAC depicted peak compressive and split tensile strength improvements of 24% and 16% compared to that of the FRAC manufactured using potable water. The application of leather factory effluent for the manufacturing of FRAC portrayed the highest water absorption (13% better than the control mix). The application of fertilizer effluent in the manufacture of FRAC presented the greatest mass loss (19% enhanced than the control mix) due to H2SO4 solution intrusion and the ultimate chloride ion migration (16 mm at twenty-eight days of testing). The summation of coal ash improved the mechanical behavior of the concrete and also caused a reduction in its durability loss of. The SEM analysis depicted that the textile factory effluent presented the most densified microstructure with the development of ettringite needles and CSH gel having refined the ITZ.