EFFECT OF REINFORCEMENT CORROSION ON THE PUNCHING SHEAR OF RC SLABS INCORPORATING MACRO SYNTHETIC FIBERS

Abstract

This paper is part of an ongoing research on the effect of discrete fiber reinforcement on punching shear strength of reinforced concrete (RC) slabs subjected to accelerated corrosion regime of steel reinforcement. Results obtained from RC slabs incorporating macro synthetic fibers will be presented. Six RC slabs (1500 mm ×1500 mm ×100 mm) were prepared with a constant reinforcing steel ratio and incorporating synthetic fibers at different dosages (0.0 %, 0.5% and 0.75% by volume). The corroded set of slabs were subjected to an impressed current (IC) accelerated corrosion regime for 36 days with an applied constant current density of 500 µA/cm2. The slabs were subjected to wetting-drying cycles of 1 day wet and 2 days dry. During the wet cycle, the slabs were fully submerged in a 3.5% NaCl solution. The applied current results in a theoretical mass loss of steel by around 7%. The slabs were tested in a simply supported configuration until failure. The measured test parameters included the applied load, the slab deflection, and monitored the observed cracking. The results showed that reinforcement corrosion affected the slabs' performance in terms of strength and deflection capacities, as well as the cracking behavior. The load-deflection response showed that the addition of synthetic fibers could reduce the impact of steel corrosion on the punching shear behavior of the RC slab. Furthermore, the presence of synthetic fibers significantly limited the development of corrosion activity in the slabs by delaying corrosion-induced cracks when compared to the control slabs.