Experimental Study On Seismic Behaviour Of SRC Column-RC Beam Subassemblages

In order to implement the performance-based seismic design(PBSD) for steel reinforced concrete(SRC) structures, the following studies are carried out: (1) Four half scale SRC column - RC beam subassemblages are tested under cyclic loading; (2) The percentages of each of the deformation components is discussed and the drift limit for different performance levels are recommended; (3) Four methods to calculate the shear strength of SRC joints were compared. And discussion has been made about the effectiveness of four parameters on the shear strength of SRC joints according to the grey conjunction theory.Based on the test results, failure patterns, hysteretic curves, skeleton curves, ductility, energy dissipation, stiffness degeneration and strength decay of SRC column - RC beam subassemblages are comprehensively analyzed. The effect of the strength ratio of joint to beam on the seismic performance of SRC column-RC beam subassemblages is especially investigated.Based on the test results, the percentages of each of the deformation components due to the beam plastic within the plastic hinge, anchorage slip in the joint and shear deformation of joint to the global deformation of the beam - column subassemblages and their characteristics are investigated.The limit states of SRC column - RC beam subassem- blages for four different performance levels are discussed. The crack width and stress level of longitudinal bar, residual deformation and degree of strength decay are suggested as the appraising parameters of four performance levels, respectively. According to the test results of SRC column - RC beam subassemblages, the drift limit for the four performance levels, i.e. fully operation, operation, repairable and collapse avoidable are suggested as 1/500, 1/150, 1/75 and 1/30, respectively.Four methods to calculate the shear strength of SRC joints which were prescribed by AISC, AIJ, YB 9082-97, and JGJ 138-2001 of China were compared. It is indicated that among the four typical methods, the AISC specification provided a conservative calculation results, the results of AIJ were more suitable for designing than the other methods, the results of YB 9082-97 is the closest one to the test results, and the specification of JGJ 138-2001 could overestimate the shear strength of SRC joints.Based on the grey conjunction theory, the effect of the four parameters, concrete strength fc, the percentages of structural steel in joint coreρss, the percentages of stirrups in joint coreρsv, and the axial compression ratio n, on the shear strength of SRC joints is analyzed and compared. It can be concluded that the order of the priority to the shear strength of SRC joints isρss, fc,ρsv and n.