Research On The Aseismic Performance Of The Frame Joint Of Steel Reinforced Concrete Column-steel Beam After Fire And Its Repair

Steel reinforced concrete composite structure is a new direction of modern steel structure andreinforced concrete structure. In this paper, through experiment and theoretical analysis of post fire,we found that the post-fire frame node of steel reinforced concrete column-steel beam’s failureform, seismic performance and shear capacity under low cyclic loading. Moreover, we also studiedthe failure mode, seismic performance and shear capacity of the repaired of post-fired steelreinforced concrete node.Through the2ordinary temperature nodes and4post-fire joints under low cyclic loading test,analyzed the post-fire steel reinforced concrete column and steel beam frame node’s failure mode,failure mechanism, researched the hysteretic curves, skeleton curve, ductility, strength degradation,stiffness degradation, energy dissipation capacity rules, and analyzed the seismic performance ofthe node affected by the fire duration time and axial compression ratioThrough the2fired steel reinforced concrete column-steel beam frame node specimens, thatone was repaired and strengthened with externally CFRP, another was encased and repaired bysteel, the nodes after the strengthening and repairing under the low cyclic loading test, analyzed thereinforced failure mode, the node’s failure mechanism, and made a comparison with the originalspecimen, based on the analysis of the hysteretic curve, skeleton curve, ductility, strengthdegradation, stiffness degradation, energy dissipation capacity and ultimate bearing capacity, thestudy found that the two kinds of reinforcement scheme can better recovery the ductility, thestiffness and energy dissipation capacity of the post-fire nodes, and found that the ultimate bearingcapacity of reinforced node increased significantly, indicating that the effect of the tworeinforcement scheme is very good for the post-fire the steel reinforced concrete columns-steelbeam joints, which repaired by steel-encased and by carbon fiber.Finally, The paper based on the experiment of the steel reinforced concrete column-steelbeam frame node and the fired node of steel reinforcement, carbon fiber reinforcement, analyzedtheir stress mechanism. And based on shear capacity formula given by " Technical specificationsof steel concrete composite structures ", Combined with theoretical analysis, Raised shearcapacity formula of the fired steel reinforced concrete columns-steel beam node,Also raised shearcapacity calculating formula of the carbon fiber reinforced node after fire and the outsourcing steelreinforced node after fire, the test results and the theoretical results are in good agreement.