Construction tolerances and design parameters for NSM FRP reinforcement in concrete beams

Aging infrastructure worldwide has made rapid means of repair and retrofitting a growing necessity. Fiber reinforced polymers (FRP) can provide a cost-effective and accelerated repair technique with near surface mounting (NSM) of pre-cured bars or strips in a bed of epoxy placed in pre-cut grooves. The performance of NSM FRP reinforcement depends on both geometric and mechanical properties of the system. Within the scope of this study, an experimental program was carried out to identify the effects of groove size tolerance on NSM FRP systems. Test results showed that the groove size tolerance up to ±22% does not affect the overall performance of such systems. The findings were also verified with a finite element model, which was then extended to study the effects of other geometric and physical parameters. Finally, a comprehensive database of test results available in the literature was compiled, and a comparative study was conducted on the geometric and material properties of the NSM FRP systems.