effect of steel fibers on the properties of recycled self-compacting concrete in fresh and hardened state

the current research intends to study the possibility of producing fiber recycled self-compacting concrete (frscc) using demolitions as a coarse aggregate (crushed red brick and crushed ceramic). steel fibers were used in recycled self-compacting concrete (rscc) to improve fresh and hardened properties of this type of concrete. thirty nine concrete mixes were prepared to achieve the aim proposed in this paper. steel fiber volume fraction varied from 0 to 2.0% by the volume of concrete with aspect ratio 65. the fresh properties of frscc were evaluated using slump flow, j-ring and v-funnel tests. compressive strength, tensile strength, flexural strength and density tests were performed in order to investigate mechanical properties. the optimum volume fraction of steel fibers was 0.25% and 1.0% for the mixes contained crushed red brick and ceramic as a coarse aggregate respectively. at optimum content of steel fibers, the compressive strength for the rscc mixes with steel fibers improved by 11.3% and 31.8% for the mixes with crushed ceramic and crushed red brick, respectively with respect to control mix. also the tensile strength and the flexural strength for the mixes were improved