Experimental investigation on the post-fire cyclic behavior of grouted sleeve connections

Abstract

Grouted sleeve connections have been widely used in precast construction for joining rebar. In order to study their post-fire seismic performance, grouted sleeve connections, which are heated first to elevated temperature and then cooled down to room temperature, are tested under both monotonic and cyclic loadings. For comparisons, the same tests are also carried out on continuous rebar. The failure modes, skeleton curves and compression strength of the specimens are analyzed to study the influence of temperature on the seismic performance of the grouted sleeve connections. The results show that buckling occurs to all the grouted sleeve connections under cyclic loading. It is also found that the skeleton curves, compressive and buckling strength of both the connections and the continuous rebar decrease with the increase of temperature up to 600 °C. From the test results and on the basis of the GMP and GA hysteric constitutive models of steel, a modified model for cyclic constitutive law of the continuous rebar and the grouted sleeve connections is presented and validated. The results demonstrate that the modified model is capable of accurately simulating hysteretic properties of steel rebars and grouted sleeve connections.