Punching Shear Performance of High-compressive Flat Slabs Reinforced with Hybrid Fibres

Abstract

A framework is presented to explore the influential role of hybrid fibers on the performance of two-way flat slabs against punching shear failure. A finite element (FE) modeling approach via the ATENA-GID software package is used to simulate the case study. Four variables are covered in this investigation including different mix proportions of hybrid fiber-reinforced concrete (HFRC), which contains 0.2% of macro synthetic fibers, and (0.68, 0.8, and 0.96%) steel fibers (SFs) (volumetric ratios), high compressive strengths of 50, 70, and 90 MPa, different main steel reinforcement ratios based on main steel bars of 16, 20, and 25 mm, as well as 150, 200, and 250 mm as thicknesses of the slab. 106 two-way slabs (1900 × 1900 mm) models were generated in this investigation, besides 8 verification materials models. Furthermore, a parametric analysis was performed on the results of FE modeling. The FE modeling results of verification materials tend to be accurate with a correlation coefficient (R² = 0.9578). Moreover, the outcomes of the study show; that the hybrid fibers' effective ratio comprises about 0.96% SFs and 0.2% macrosynthetic fibers, using 0.54% of main steel reinforcement ratio which is supposedly more economical than other ratios of main reinforcement, 150 mm is a crucial thickness of the flat slab with 70 or 90 MPa as high compressive strength. The combined results can enhance the performance of the flat slab by preventing shear punching failure.