Strengthening of Rc Structures with near Surface Mounted Frp Rods

Disclaimer The contents of this report reflect the views of the author(s), who are responsible for the facts and the accuracy of information presented herein. This document i s disseminated under the sponsorship of the Center for Infrastructure Engineering Studies (CIES), University of Missouri-Rolla, in the interest of information exchange. CIES assumes no liability for the contents or use thereof. The mission of CIES is to provide leadership in research and education for solving society's problems affecting the nation's infrastructure systems. CIES is the primary conduit for communication among those on the UMR campus interested in infrastructure studies and provides coordination for collaborative efforts. CIES activities include interdisciplinary research and development with projects tailored to address needs of federal agencies, state agencies, and private industry as well as technology transfer and continuing/distance education to the engineering community and industry. ABSTRACT The use of Fiber Reinforced Polymer (FRP) materials has proved to be one of the most exciting and effective technologies for external strengthening of reinforced concrete (RC) and masonry structures. In this context, Near Surface Mounted (NSM) FRP rods are now emerging as a promising technique in addition to externally bonded FRP laminates. Embedment of the rods is achieved by grooving the surface of the member and placing the rods in the epoxy-filled grooves. The overall objective of this research project was to investigate the effectiveness of NSM FRP rods as a strengthening system for RC and masonry structures. The research protocol started from the characterization of the tensile properties of the FRP rods (material level). Then, the mechanics of the bond of NSM FRP rods embedded in concrete and concrete masonry units was experimentally investigated by using coupon-size specimens (subsystem level). Finally, testing of eight full-size RC beams strengthened in shear with this technique w as performed (structural member level). Results showed that NSM FRP rods can significantly increase the shear capacity of RC members. A simple shear design approach was developed and, when applied to the tested beams, appeared to give a reasonable and conservative estimate of the ultimate load.