Experimental Study Of Steel Reinforced Concrete Beam-Steel Reinforced Super-high-strength Concrete Column Joints

The excellent seismic performance of steel reinforced concrete (SRC) structure and the fast development of super-high-strength concrete (SHSC) will promote the application of SHSC to SRC structures in the future. For complicated mechanical property and construction of joints, and concrete brittleness caused by high strength, the theoretical studies of steel reinforced concrete beam-steel reinforced super-high-strength concrete column (SRC-SRSC) joints lag behind engineering application, and the studies on seismic performance of them are few at home and abroad presently.In this paper, the tests of six SRC-SRSC joints under low cyclic reversed load are carried out. Compared with RC joints and SRC joints, the mechanical behaviors of SRC-SRSC joints including crack development, failure patterns and deformation characteristic are analyzed. According to seismic hysteresis curves and skeleton curves obtained by joint tests, restoring force characteristics of SRC-SRSC joints including ductility, energy dissipation, strength and rigidity degradation are analyzed, and the influences of axial compression ratio and stirrup ratio on the seismic behaviors of frame joints are discussed. Test results show that SRC-SRSC joints possess good seismic behaviors, strong energy dissipation and ductility. The mechanism of crack resistance and the shear calculating methods of SRC-SRSC joints core are discussed on the basis of the tests. Then, a calculating formula of crack resistance of the joint is derived. The results indicate that the calculation agree well with those obtained from tests.The study results will be the basis of the elastic-plastic dynamic analysis, which provide theoretical foundation for establishing reasonable calculation theories and design methods of SRC-SRSC joints to promote the development and application of the excellent seismic structures.