Numerical study on interaction between steel stirrups and shear- strengthening NSM FRP strips in RC beams

RC beams shear-strengthened with externally bonded or near-surface mounted (NSM) FRP reinforcement usually fail by the debonding of FRP in a brittle manner. When the FRP reinforcement debonds, the internal steel stirrups may have not reached their yield strength, so the contribution of the latter to the shear resistance of the beam is compromised to some extent. This phenomenon is referred to as the adverse shear interaction between the steel stirrups and the bonded FRP shear reinforcement. This paper examines such shear interaction in RC beams shear strengthened with NSM FRP strips using a simple computational model. Numerical results obtained from this model show that in such beams, most of the steel stirrups reach their yield strength, so the interaction does not have a significant adverse effect on the shear resistance of the beam. This may be seen as yet another advantage of the NSM FRP strengthening method. Disciplines Engineering | Science and Technology Studies Publication Details Chen, G. M., Li, S. W., Zhang, S. S., Chen, J. F. & Teng, J. G. (2013). Numerical study on interaction between steel stirrups and shearstrengthening NSM FRP strips in RC beams. In R. Al-mahaidi, S. T. Smith, Y. Bai & X. Zhao (Eds.), Proceedings of the 4th Asia-Pacific Conference on FRP in Structures (APFIS 2013) (pp. 1-6). Victoria, Australia: Swinburne University of Technology. This conference paper is available at Research Online: http://ro.uow.edu.au/eispapers/4955 NUMERICAL STUDY ON THE INTERACTION BETWEEN STEEL STIRRUPS AND SHEAR-STRENGTHENING NSM FRP STRIPS G.M. Chen , S.W. Li , S.S. Zhang , J.F. Chen 1,3 and J.G. Teng 2 1 School of the Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, China 2 Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, China. 3 School of Planning, Architecture and Civil Engineering, Queen’s University Belfast, UK. Email: J.Chen@qub.ac.uk