Strengthening of punching shear of flat slab–column connections through hybrid near‐surface mounted and externally bonded systems: Experimental, numerical, and analytical study

Abstract Slab–column connections are vulnerable to punching shear, particularly when flexural cracking reduces the effective depth. This study proposes a sustainable dual‐strengthening system to enhance punching resistance and combined flexural–punching performance. The approach integrates near‐surface mounted galvanized steel wire rope (NSM‐GSWR) as through‐thickness stitching reinforcement with‐and‐without externally bonded reinforcement using stainless steel strips (EBR‐SS) applied on the flexural side. An experimental program was performed on full‐scale reinforced concrete slabs under monotonic static loading until failure, examining the effects of strengthening quantity, configuration, technique, and location. NSM‐GSWR was installed at critical distances from the column face ( x = d and 1.5 d ), while EBR‐SS was presented in cross‐line and inclined patterns. Performance was evaluated in terms of ultimate capacity, crack development, stiffness, and energy absorption. Strengthening increased ultimate capacity by up to 89% and promoted ductile failure, while EBR‐SS delayed cracking and enhanced NSM‐GSWR effectiveness. Finite element simulations in ABAQUS, supported by parametric sensitivity analysis, closely matched experimental outcomes with expectation errors below 5%. A validated parametric model confirmed the strong effect of GSWR amount on punching capacity. Furthermore, a new design‐oriented equation based on critical shear crack theory was derived, reliably determining the required GSWRs with an error margin below 4%.