Evaluation of Fracture Energy of Composite-Concrete Bonded Interfaces Using Three-Point Bend Tests

Abstract

In this paper, a conventional test method using a notched three-point bending beam (3PBB) specimen is adapted to characterize Mode I fracture of composite-concrete bonded interfaces, and the interface fracture energy is evaluated based on a fictitious crack model. Two types of fiber fabrics—E-glass and carbon—are used, and a common epoxy resin is applied to bond the composite fabriçs to concrete. Mode I fracture tests of the 3PBB specimens for carbon fiber reinforced polymer (CFRP)- and glass fiber reinforced polymer (GFRP)-concrete bonded interfaces are performed to determine the applied load and load point displacement relationship from which the interface fracture energy is computed. The effects of loading rates, types of fiber fabrics, and curing time on the fracture energy of FRP-concrete bonded interfaces are studied and discussed. It is expected that the proposed experimental method can be used effectively to obtain fracture data for performing delamination studies under various environmental exposures and service loading.