Experimental Study on Mechanical Properties of Large-Diameter Steel Grouting Sleeve under Cyclic Loading

To study the mechanical properties of large-diameter rebar grouting sleeves (GS) in prefabricated bridge piers, 40 mm diameter GS specimens were designed and subjected to high-stress cyclic and large-deformation cyclic axial tension tests. The influences of the anchorage length and loading method on the failure mode, structural performance, and bond strength were analyzed. The results show that the specimens are in an elastic state under high-stress loading and exhibit plastic characteristics under large-deformation loading. As the anchorage length decreases, the failure mode changes from rebar fracture to slip failure, and an anchorage length of 7d can meet the seismic requirements. The eccentricity of the rebar has no significant effect on the ultimate bearing capacity. The test reveals that the average bond stress decreases with the increase of the anchorage length, and the longitudinal and transverse strain values on the sleeve surface decrease from the middle to the ends. A calculation formula for the bond strength between the rebar and the grouting material with a safety factor was established through data fitting. The research confirms that the large-diameter rebar GS connection has reliable seismic performance and can be used as an effective connection method for prefabricated bridge piers.