Behavior of Flat Slabs with Partial Use of SIFCON Subjected to Concentrated Loading

Abstract

This research investigates the applicability of slurry-infiltrated fiber concrete (SIFCON) to enhance ductility and punching shear capacity. In addition, especially since the SIFCON mortar is considered self-compacting, thus reduces the labor costs associated with concrete vibration. Eight flat slabs with dimension 600 × 600 × 60 mm, were cast and tested under concentrated loading. The main experimental parameters investigated were the type of concrete (NSC and SIFCON), the placement of SIFCON within the slab, and the proportion of the slab area composed of SIFCON. Among the tested specimens, one slab was constructed entirely with NSC and another entirely with SIFCON; these two slabs served as reference specimens for comparative evaluation. The experimental results are presented, including maximum load, deflection, ductility, and rotation, as well as the crack pattern of each specimen and the inclination of cracks. According to the test results, punching shear of RC slabs and deformation capacities are considerably increased by using SIFCON. The percentage increase in punching shear capacity of the slab with SIFCON layer 40 mm in the tension face was 112%, and the ductility of the slab with SIFCON layer 20 mm in the tension face was 117%, compared with the reference slab. Furthermore, by increasing the post-punching deformations of slabs, the strengthening approach may also be applied to prevent structures from collapsing suddenly following punching shear failure.