Flexural Capacity of Sustainable RC Beams Manufactured with Treated Wastewater, RCA, and Fly Ash

Abstract

Sustainable concrete with recycled materials has recently received considerable interest among researchers. Of the available recycled materials, treated wastewater (TWW), recycled concrete aggregates (RCA), and fly ash (FA) were prominently employed in concrete applications in recent years. Accordingly, this study experimentally explores the combined effect of TWW, RCA, and 20% FA on the flexural behavior of reinforced concrete (RC) beams. Concrete mixes were investigated for their mechanical properties. Also, flexural tests were conducted on four RC beams with dimensions of 180 mm width, 250 mm height, and 2000 mm length. The results demonstrated that the use of TWW, RCA, and FA decreased concrete compressive strength by 6% to 16%. In addition, TWW and RCA decreased the beams’ ductility by 10% and 16%, respectively. Moreover, the flexural capacity of the beams decreased by 14% when TWW was used, whilst RCA showed no effect on the flexural capacity of the beams. Furthermore, FA showed a 5% to 7% improvement in the ultimate loading capacity of the beams.