Experimental study on mechanical behavior of thermally damaged grouted sleeve splice under cyclic loading

摘要

An experimental program concerning 48 specimens of grouted sleeve splices, first heated up to 600 degrees C and then subjected to cyclic loading was presented and discussed in this study. Similar rebar splices were often used in the precast concrete structures designed for seismic regions. The temperature of the splice and the compressive strength of the grout were the main variables considered in this study. It is found that the temperature mainly affected the peak bearing capacity of the grout and the failure pattern of the connection. In fact, the typical failure pattern at room temperature (rebar fracture outside the sleeve) turned to rebar pullout of the sleeve above 400 degrees C, which indicated that below this temperature grout-to-rebar bond kept most of its original efficacy. On the contrary, bond failure occurred for all specimens at 600 degrees C because of rebar slip. A calculation method was proposed as well to evaluate the peak bearing capacity of grouted sleeve splice, based on the load transferring mechanisms of the bond between grout-to-rebar and sleeve-to-grout. The conducted experimental study and analysis provide a better understanding on the bond mechanism of thermally damaged grouted sleeve splices subjected to cyclic loading.