STUDY ON MECHANICAL BEHAVIORS OF POST-FIRE GROUTED SLEEVE CONNECTIONS UNDER LARGE STRAIN OF CYCLIC LOADING

Grouted sleeve connection is one of the main measures for steel rebar splicing of precast concrete structures at present. Aimed to figure out the stress state of sleeve, a post-fire grouted sleeve connection experiment with 12 specimens under large strain of cyclic loading was exerted to investigate the stress distribution development of sleeve and mechanical behaviors of the specimens by taking the elevated temperature and earthquake into account. There were lots of findings when the compressive strength of grout was 61.3 MPa as follows: the sleeve is in elastic state in the circumferential direction and elastic-plastic state in the longitudinal direction in the middle of the sleeve; the crucial temperature is 400℃ when the failure pattern of post-fire specimens changes from rebar fracture outside the sleeve to the bond slip failure between grout and steel rebar; compared to the values at ambient temperature, the peak load and peak displacement of the post-fire specimens decrease about 12% and 17% respectively.