Research on the flexural performance of recycled coarse aggregate concrete beams after carbonation

Abstract

This paper discusses the flexural behavior of carbonated recycled aggregate concrete (RAC) beams through experimental data. We produced fifteen beams, each varying in recycled aggregate replacement ratios: 0 %, 30 %, 50 %, 70 %, and 100 %. Each replacement ratio included three beams, amounting to different levels of carbonation: non-carbonated, partially carbonated, and completely carbonated. Post accelerated carbonation processes; flexural testing was conducted. The findings reveal that beams incorporating varying amounts of recycled coarse aggregates (RCA) but maintaining identical carbonation levels exhibited a minor reduction in the cracking moment, with negligible variations in ultimate flexural strength and deflection. Moreover, beams sharing the same RCA replacement ratio demonstrated increased cracking moment, ultimate flexural strength, and stiffness with advancing carbonation levels, while deflection tended to decrease. Based on these findings, predictive models for cracking moment and ultimate flexural strength of carbonated RAC beams were developed. Comparisons between experimental outcomes and numerical simulations, particularly within the RAC50 group, indicated nearly identical results.