New Device for In Situ Testing of Fiber Reinforced Polymer/Concrete Adhesion

Fiber reinforced polymer (FRP) is proving to be increasingly cost-effective as a solution for the repair and rehabilitation of substandard concrete structures. As the integrity of the repair is dependent of the FRP/concrete bond, its evaluation for both acceptance and long-term maintenance purposes is of obvious importance. FRP/concrete adhesion is currently evaluated from the more common tension test or the less used shear test. In either test, a metal disk called a dolly is bonded to the FRP surface. The forced needed to separate the dolly under tensile or shear loads is used to determine the FRP-concrete interface adhesion. The similarity of the procedures for the two tests suggests it would be logical to develop a single device that could be used to conduct both in-situ tension and shear tests. The basis and development of a new device that allows both tension and shear tests to be carried out in-situ are described. The device is simple to use and only requires an instrumented socket wrench to apply the separation load. Preliminary results from tests carried out to assess the role of different surface finishes on the FRP/concrete bond are presented to demonstrate the application of the device.