Behavior analysis and strength prediction of steel fiber reinforced recycled aggregate concrete column under axial compression

This paper presents an experimental and analytical study of the behavior of steel fiber reinforced aggregate concrete (SFRRAC) columns under axial compression. A total of thirteen axially loaded SFRRAC column specimens were manufactured to investigate the effects of steel fiber volume fraction, recycled coarse aggregate (RA) replacement ratio and stirrup spacing on the compression performance. The results showed that the steel fibers and stirrups could improve the strength and ductility of the axially loaded SFRRAC column, and the RA had an insignificant effect on the column performance. The steel fibers could improve the mechanical properties of the concrete mixture and control the cover spalling of concrete column. In addition, the coupling effect of steel fibers and recycled aggregate (RA) on the column strength was quantified and the equation for predicting the replacement effect of steel fibers to stirrups was proposed. It was found that 1% steel fibers could allow for 100% replacement of NA by RA and replace 34-56% of the transverse stirrups based on the principle of equivalence strength. Finally, a model for predicting the load capacity of axially loaded SFRRAC column was established, which produced a good agreement with the experimental results. (c) 2021 Elsevier Ltd. All rights reserved.