Punching shear behavior of geopolymer concrete two-way flat slabs incorporating a combination of nano silica and steel fibers

Abstract

This research was conducted by performing center point load tests on the two way flat slab samples to investigate the combined effects of steel fiber (SF) and Nano-silica (NS) on the punching shear and deflection capacities of ten slag-based Geopolymer Concrete (GC). This study consists of two parts; in the first part, the effects of only SFs were investigated, while in the second part the combined effects of NS and SFs on the properties of GC were examined. During the study, two types of hook-end SFs (0.5% and 1%) and only 2% NS were used. The tested slabs showed that the energy absorption capacity/toughness of GC slabs was positively affected by the inclusion of NS and SFs. Also, it was favorably influenced by SFs content and aspect ratio. Furthermore, these slabs were categorized. While, NS and SFs enhanced the punching shear strength of the slabs, the combined influence of NS and SFs exhibited better the punching shear capacity compared to individual utilization. It is clear from the experimental studies that the slab with the combination of NS and SF2 outperformed all of them and showed 131.08% higher strength bearing capacity than the slab without SFs and NS.