Anchorage Systems Used in FRP Strengthening of Concrete Members: Fid-Bau Portal

Anchorage Systems Used in FRP Strengthening of Concrete Members

Jumaah, Reem / Kalfat, Robin / Al-Mahaidi, Riadh / Abdouka, Kamiran

Abstract In response to escalating demands to increase the strength of existing structures, new strengthening technologies have evolved, such as the use of fibre composite materials (FRPs) as externally bonded reinforcement. In spite of their potential benefits, the use of externally bonded FRP systems is hampered by the occurrence of premature debonding. Improvement in the efficiency of FRP systems is an area of ongoing research that is still in its infancy. However, promising results have been achieved by the use of anchorage systems, such as bidirectional fibre patch anchors applied to the ends of the FRP to improve the FRP-to-concrete bond performance. Although previous experimental studies on patch anchors have demonstrated significant enhancements in the strength of FRP-to-concrete joints when tested using a near end supported direct shear test, the performance of patch anchors when applied to large-scale beams remains to be investigated. The present paper presents an experimental study where large scale post-tensioned T-beams were strengthened in shear using FRP and later modified by the inclusion of bidirectional fibre patch anchors. The results suggest that the addition of bidirectional fibre patch anchors significantly enhance the maximum laminate strains attained prior to beam failure, in addition to increasing the peak failure load. The research highlights the importance of the influence of potential beam failure mechanisms on the bond performance of FRP patch anchors due to the possibility of shear failure within the FRP anchorage zone, and shows that such failure does not typically occur in direct shear tests.