Review on NSM-CFRP Method for Enhancing Shear Capacity in Reinforced Concrete Deep Beams

The demand for improved strengthening techniques for current concrete structures is on the rise. Many structures that will still be in use two decades from now have already been constructed. A portion of these structures must undergo enhancements or be replaced, as they are deteriorating not only from natural processes but also from mistakes made during their design and construction. Near-surface mounted (NSM) utilizing Fiber-Reinforced Polymer (FRP) bars has proven to be a successful method in enhancing the flexural and shear performance of both existing and new Reinforced Concrete (RC) elements. This technique is considered innovative and rapidly developing, attracting significant attention from researchers. Therefore, this study aims to analyze previous and current research on the shear strengthening of RC deep beams using NSM-CFRP bars. The research findings were gathered from four prominent databases: ASCE, EBSCO, SCOPUS, and Science Direct. A thorough literature review was conducted, focusing specifically on NSM-CFRP for shear strengthening. A total of 56 articles were categorized into three main groups. Group 1 consisted of studies examining the use of NSM for shear strengthening, while Group 2 focused on articles related to the structural behavior of RC members in shear. Group 3 included articles discussing the theoretical aspects of NSM-FRP in enhancing shear strength, aiming to develop a new method for calculating shear effects provided by NSM-FRP. In conclusion, this study highlights three fundamental aspects of this field: (1) the rationale behind utilizing NSM-FRP bars for shear reinforcement and their practical applications, (2) existing challenges and barriers to widespread adoption, and (3) recommendations for enhancing the acceptance and utilization of NSM-FRP bars.