Flexural capacity prediction of steel fiber reinforced concrete beam with recycled fine and coarse aggregate

Abstract

In this study, the flexural performance of the steel fiber reinforced concrete beams with recycled fine and coarse aggregates was investigated through the experiments. The effects of steel fiber volume fraction, recycled fine and coarse aggregate replacement ratio, and concrete compressive strength grade on the flexural performance of steel fiber reinforced recycled aggregate concrete (SFRAC) beams were systematically studied in terms of failure mode, flexural capacity, cracking patterns, load-deflection response, and load-tensile reinforcement strain response. The results showed that the flexural capacity and deflection of beams increased and decreased with the increase of steel fiber volume fraction, respectively. The beam with 100% replacement ratio of recycled fine aggregate and 0.5% volume fraction of steel fiber presented the similar or even better flexural performance than that of the ordinary concrete beam. By adding 1.0% volume fraction of steel fiber, the flexural capacity of beam with both 100% replacement ratio of recycled fine and coarse aggregates was higher than that of the ordinary concrete beam. Based on the experimental results of SFRAC beams in this study and other literature, the effects of steel fiber volume fraction and recycled aggregate replacement ratio on the flexural capacity of beams were quantitatively analyzed. Lastly, a model for the prediction of SFRAC beam flexural capacity was proposed and verified.