Behavior of recycled steel fiber reinforced concrete under uniaxial cyclic compression and biaxial tests

Abstract

In this study, the behavior of recycled steel fiber reinforced concrete (RSFRC) is investigated through uniaxial cyclic compression and biaxial tests conducted on 56 cubic specimens with four admixtures of RSF-content. The results obtained from cyclic compression tests show that the presence of RSFs reduces the damage of specimens in the post-peak regime which leads to an increase of residual strength. Furthermore, the biaxial failure-stress envelopes constructed based on the biaxial testing results indicate that an increase in RSF-content expands the failure envelope. Consistently, maximum biaxial strength for all specimens is found to occur at a stress confinement ratio α=~0.44-0.48. Moreover, measurements show that the failure biaxial strain significantly increases with increasing the RSF-content. The biaxial test results are found in good agreement with the literature on steel fiber reinforced concretes (SFRCs) indicating that industrial steel fibers can be substituted by RSFs which are environment-friendly. Employing these results, a model for the biaxial behavior of RSFRCs is proposed which can be employed in the constitutive relations required for the modeling of RSFRCs as well as SFRCs.