Bond performance of FRP to concrete using vacuum and heat/resin injection

Fibre reinforced polymer (FRP) materials have been used to enhance the structural capacity of deteriorated structures based on the high performance of the composites. Since, debonding of the FRP material from the substrate is a brittle failure, it is essential to study this phenomenon and propose significant ways to improve the behaviour of the bondline. Two techniques for the application of FRP that adopt a vacuum consolidation process and heat/resin injection to improve the curing process, bond strength and speed of application have been adopted. The vacuum can contribute to the penetration of the resin into the surface around the exposed aggregates in order to achieve higher bond in strengthened elements. In this article, the interfacial bond behaviour of FRP laminates attached to concrete in the presence of vacuum and heat/resin injection is studied. The results of single lap shear tests have been utilized to investigate the capability of this system in strengthening of concrete element and the effect of bondline thickness on the bond performance of adhesively bonded joints.