Experimental study on grooving detail for elimination of debonding of FRP sheets from concrete surface

Abstract

Debonding of FRP sheets from concrete surface has been a challenging phenomenon attracting many researches in recent years. Surface preparation of concrete before attaching FRP sheets is considered a suitable method to postpone debonding, but with limited effects. Grooving is an innovative technique to overcome debonding of FRP laminates from concrete surface, which has been recently used in Isfahan University of Technology (IUT). In this paper, the effect of different factors influencing the grooving capability is addressed aiming at reducing the debonding potential of FRP sheets from the concrete surface. These factors include the width and the depth of the grooves. The laboratory specimens included about thirty 100×100×500 mm plain concrete beams. Having been grooved on the surface, the specimens were reinforced with CFRP sheets and underwent the four-point flexural test so as to measure the ultimate loading capacity. The outcomes demonstrate that, debonding can be completely averted or at least to a large extent limited by considering specified width and depth for the grooves. © Tsinghua University Press, Beijing and Springer-Verlag Berlin Heidelberg 2011.