Bond test of lapped rebars and concrete: some preliminary results

When a steel rebar inside a reinforced concrete member is overloaded, it yields and experiences reduction in cross section area. In particular when pit corrosion occurs on steel rebar, reduced effective cross section leads to stress concentration. Snapping of steel rebar may become the worst situation. With this occurrence, the composite action of concrete and steel will be totally lost. In order to recover the performance of RC members with snapped (or about to snap) steel rebar, a new rebar splice arrangement is proposed. The new splice employs the use of separated straight bars to provide overlapping effect to the two snapped portions of main steel rebar. The new arrangement allows no misalignment of main reinforcement. In this preliminary study, a series of test specimens containing the lapped rebars were tested, the main variable in the experiment was the length of additional lapping bars. The effects of constant bending and constant shear loading condition on the splice strength were investigated and reported in this paper.