punching shear performance of reinforced concrete slab-column joints with shearhead reinforcement

The punching shear performance of reinforced concrete (rc) slab–column joints with shearhead reinforcement was investigated to optimize shearhead reinforcement design. nine slab–column joint specimens were designed with different flange thicknesses, web thicknesses, cantilever lengths, and anchor stud sizes. the specimens were subjected to reversed static loading tests to investigate their failure history and failure modes# measure the load capacity, deformation, and strain of the joints# investigate the influence of different design combinations on the punching shear failure mode and load capacity of the joints# and elucidate their failure mechanisms. test simulation analysis and numerical parametric analysis were conducted based on the test results. the results showed that the shearhead enhanced the punching shear performance of the slab–column joint and improved the brittleness of the punching shear failure. installing steel section flanges and anchor studs enhanced the synergy among the longitudinal reinforcement, steel section, and concrete in the joint, and increasing the web thickness and installing flanges both improved the punching shear capacity and ductility of the joint. the installation of flanges on the web of the steel section increased the ultimate load capacity by more than 40% and increased the mid-span displacement at failure by more than twice that of the specimen without flanges and the specimen with studs. adding anchor studs to the web of the steel section increased the ultimate punching shear capacity of the rc slab–column joint by 25%. using anchor bolts instead of flanges improved the punching shear capacity of the joint but was not as effective in improving ductility. increasing the flange thickness to increase the load capacity had a marginal effect# the ultimate load capacity increased by only 7% when the web area increased by 2/3, and the shearhead did not enhance punching shear capacity if the cantilever of the steel section was too short. finally, based on the existing code, test results and numerical parametric analysis results, a method for calculating the punching shear capacity of rc slab–column joints with shearhead reinforcement was proposed. © the author(s), under exclusive licence to the iran university of science and technology 2024.