Experimental research on dynamic mechanical properties of fully-grouted sleeve connections

Abstract

Previous studies have shown that the mechanical properties of the sleeve grouting connection under cyclic loading are different from the static properties, but the influence of dynamic loading on the performance of fully-grouted sleeve connection still needs to be studied. In this paper, the dynamic characteristics of fully grouted sleeve connection under loading rates of 0.6 mm/s, 6 mm/s, and 60 mm/s were studied through static and dynamic tensile tests on 29 specimens. The results showed that the failure mode of 27 specimens was tensile fracture of steel bars, and 2 specimens’ failure mode was steel bar pullout failure; Under the dynamic loading, the bearing capacity and maximum strain were higher than that of the static one. At the loading rate of 0.6 mm/s, 6 mm/s, and 60 mm/s, for the specimens with steel bar diameters of 12 mm and 14 mm, the yield load and bearing capacity increased with the increase of the loading rate. When the steel bar diameter was 16 mm, the yield load and bearing capacity of the specimen presented a trend of first increasing and then decreasing. When the anchorage length is insufficient, the steel bar of specimen will be pulled out and damaged. The bond strength is the key to the failure mode of the fully grouted sleeve connection. Bond strength coefficient k can be used to calculate the bond strength of the specimen with full grouting sleeve of this type of sleeve against reinforcement pulling out, so as to prevent the specimen from being damaged by the steel bar pull-out.