Strengthening of Spliced Reinforced-Concrete Beams Using Near-Surface-Mounted (NSM) Steel Bars

This research investigates the structural behavior of precast spliced reinforced-concrete beams strengthened using Near-Surface-Mounted (NSM) steel bars. Full-scale RC beam specimens with mid-span splice joints were tested under four-point bending to evaluate flexural capacity, stiffness, ductility, crack development, and service-load deflection. The results show that NSM steel reinforcement significantly enhances structural performance, increasing ultimate load capacity by up to 133%, stiffness by 93%, reducing service-load deflection by 59%, and improving ductility by 20%. The findings demonstrate that NSM strengthening provides a practical and effective method for upgrading spliced RC beams and restoring near-monolithic behavior.