Flexural performance of recycled aggregate concrete beams reinforced with basalt fiber-reinforced polymer or steel bars

Abstract This paper reports on the results of an experimental study on the flexural performance of recycled-aggregate concrete beams reinforced with basalt fiber-reinforced polymer (BFRP) bars. A total of eight reinforced concrete (RC) beams were prepared and tested under four-point loading. The parameters investigated included: (1) concrete mixture (0, 25, 50, and 100% use of recycled concrete aggregates (RCA)) and (2) reinforcement material (steel/BFRP). The results revealed minimal effects of the use of RCA on the flexural behavior of RC beams. Altering reinforcement material, on the other hand, showed a significant effect on the flexural behavior of RC beams: using BFRP (instead of steel) reinforcement reduced the deformational performance but yielded comparable ultimate capacity of RC beams at 0% and 100% RCA replacement ratios. The cracking loads and crack spacings of steel RC beams were generally higher compared to BFRP-RC beams at the same RCA replacement ratio. Theoretical investigations of ultimate capacities and service load deflections were performed for the tested beams based on contemporary design guides and were compared with the experimental results. The findings of this study underscored the potential of using RCA and BFRP bars as sustainable alternatives to the conventional materials in reinforced concrete.