EXPERIMENTAL INVESTIGATION ON PERFORMANCE OF DEFECT DETECTABLE AND REPAIRABLE HALF GROUTED SLEEVE CONNECTION UNDER HIGH STRESS CYCLIC TENSION-COMPRESSION LOAD

To improve the unreliable connection performance of grouted sleeves caused by the filling defect, a defect detectable and repairable half grouted sleeve connection had been proposed by the authors. In order to identify the performance of this new connection under high stress cyclic tension-compression load, 26 specimens, with the consideration of two different diameters of rebar, four grouting defect ratios and two repair methods, were manufactured and tested. The failure modes, bearing and deformation capacities of the specimens without defection, with different defect ratio and the repaired specimens were compared and analyzed. The results indicate that the connection performance of the specimens with high defect ratio is significantly affected by the cyclic tension-compression load. Once the ratio reaches a threshold, a bar slip failure mode is observed for these specimens, and the tensile capacity as well as deformation capacity are significantly lower than those of the specimens without defection. The threshold decreases with the increase of the diameter of rebar. For the specimen with a diameter of 20 mm and a defect ratio of 60%, the bar slip failure is observed before the rebar yields. In contrast, the repaired specimens and specimens without defection both exhibit a tensile failure mode, and the bearing as well as deformation capacities are approximately identical for these specimens. In addition, grout-repaired and epoxy-repaired specimens both satisfy the requirements specified in the associated code, thus validating the rationality and reliability of this new type of half grouted sleeve.