Testing and modeling of deep beams strengthened with NSM-CFRP reinforcement around cutouts

Abstract

The behavior of reinforced concrete (RC) deep beams strengthened with near-surface-mounted carbon fiber-reinforced polymer (NSM-CFRP) reinforcement around cutouts is examined in this study. The study comprised experimental testing, numerical simulation, and strut-and-tie modeling (STM). Three different NSM-CFRP strengthening solutions around the cutouts were developed using STM. The investigated parameters included the amount and orientation of NSM-CFRP reinforcement. The NSM-CFRP solutions fully restored the original shear strength, except in two cases where only 93 % and 94 % of the capacity were restored. Finite element (FE) models were developed to simulate the nonlinear behavior of the tested beams. The strength predicted by the FE models were insignificantly different from those measured experimentally. The nonlinear deflection response, CFRP strain response, and crack patterns predicted numerically were in good agreement with those obtained from the tests. The STM tended to provide a conservative prediction for the nominal strength of the tested beams.

Keywords

• Deep beams
• Cutout
• NSM-CFRP
• Strengthening
• Numerical
• STM