State of Research on Shear Strengthening / Repairing of RC Beams with Ultra-High-Performance Concrete (UHPC)

Abstract This paper presents a comprehensive review of recent research on the application of ultra-high-performance concrete (UHPC) layers for enhancing the shear strength of reinforced concrete (RC) beams. The first part of the paper presents a detailed literature review, culminating in a database of experimental tests on UHPC shear-strengthened RC beams. The analysis of the database reveals that UHPC overlays substantially enhance the shear capacity of RC beams. The experimental evidence shows that UHPC overlays demonstrated an increase in the shear strength of RC beams by up to 188%. Several key parameters, including the UHPC layer configuration, characteristics of the UHPC layer, bonding technique, and others, influence this strengthening method’s effectiveness. Researchers have reported various failure modes, such as fibre fracture and detachment of the UHPC layer. Furthermore, observations suggest a potential interaction between the internal transverse steel reinforcement and the UHPC layer. The second part of this paper focuses specifically on the shear repair of RC beams using UHPC. The effectiveness of UHPC overlay repair techniques is significantly enhanced by a reinforced UHPC layer with FRP, which enhances its tensile characteristics. Finally, this research highlights current UHPC issues and recommends future work.