Evaluating Punching Shear Strength in Basalt-Reinforced Slabs: An Experimental Analysis of Eccentric Loading and Reinforcement Ratios

The current investigation focused on evaluating the punching shear strength of flat-edged slabs reinforced with basalt bars. Nine slabs measuring 2000 mm × 1200 mm × 150 mm were tested, each featuring a 250 mm × 250 mm square column positioned at the middle free edge. In Group I, the basalt reinforcement ratio ranged from 1.5 to 2.5 times the balanced reinforcement ratio, with zero eccentricity of applied load. Group II maintained the same reinforcement ratio but introduced an eccentricity ratio of the load to column cross section depth e/h with 0.4 toward and perpendicular to the free edges of the slabs. Group III varied the e/h to 0.8. The study demonstrated the effects of basalt reinforcement ratio, eccentricity of the applied load, mode of failure, strains, and crack patterns for the specimens. Additionally, an equation for the punching shear capacity of flat slabs was proposed. Furthermore, the experimental results and the proposed equation were compared with codes and other equations that researchers use to assess punching shear capacity.