Bond behavior of fully bonded CFRP-concrete interface with improved double shear tests

An improved double-shear pull testing method was proposed with the improvements of loading fixture, fastening, and clamping devices to discuss the bond behavior of fully bonded carbon fiber reinforced polymer (CFRP)-concrete interfaces. The improvements provided a stable CFRP-debonding process due to the anchorage effect of the peripheral fasteners. Using the improved method, double-shear experiments with fully bonded CFRP (bond width ratio β = 1) could be carried out successfully, and the bond-slip relationships of the interface on any cross-sections (lines) of the fully bonded CFRP could be obtained. All of the valid experimental data show a better linear relationship between maximum bond stress τmax and corresponding slip s0, and a simple bond-slip model was proposed based on Popovics's equation.