Comparison of FRP-to-concrete anchored joints designed for FRP shear-strengthened RC T-beams

The objective of this study is to evaluate the bond performance of various anchorage methods that can particularly be used for fibre reinforced polymers (FRP) shear-strengthened reinforced concrete (RC) T-beams. Overall, twenty-five bond tests are carried out with two different experimental test setups that simulate the behaviour of an anchored FRP shear-strengthened beam. The anchorage methods considered include mechanical anchors, extending FRP laminates to the underside of beam's flange, longitudinal FRP plates, FRP bar inserted in a groove, and CFRP rope inserted through the beam web. Each specimen consists of two concrete blocks, and the load is applied by pulling the two blocks apart to produce tension in the FRP laminates. Experimental results show that both bond strength and ductility are affected by the anchorage method used. In particular, extension of the FRP laminate underneath the flange was highly vulnerable to debonding, whereas longitudinal FRP plates applied at the web extremities achieved the highest bond load.