| Compared with reinforced concrete structure, steel reinforced concrete structure has been widely used due to its higher carrying capacity, better ductility and many other advantages. The majority of previous studies were focused more on the mechanical properties of monolithic steel reinforced concrete frame joint, but less on that of prefabricated steel reinforced concrete frame joint with steel welded connection. Based on the former considerations, two prefabricated steel reinforced concrete frame interior joint combinations, two reinforced concrete frame interior joint combinations, two prefabricated steel reinforced concrete frame exterior joint combinations and two reinforced concrete frame exterior joint combinations were designed. Quasi-static loading tests were conducted while the column axial loads were constant. The failure pattern, ductility, carrying capacity degradation, stiffness degradation and energy dissipation of joint combinations are discussed in detail, and the feasibility of steel welded connection by variation of strains in beam connection area and column connection area are evaluate. Also an equation calculating ultimate shear-resistant capacity of joints and an equation calculating crack-resistant capacity of joints are presented. The main content is described as follows:(1)The axial compression ratio has no effect on the failure pattern of prefabricated steel reinforced concrete frame interior joint. The prefabricated steel reinforced concrete frame interior joint performs higher carrying capacity and better ductility compared with the reinforced concrete frame interior joint. The energy dissipation capacity of the prefabricated steel reinforced concrete frame interior joint is better due to its better plastic deformation capability. The carrying capacity and stiffness of the prefabricated steel reinforced concrete frame interior joint decline sharply under higher axial compression ratio, and the ductility factor and energy dissipation of the joint combination decrease as the axial compression ratio increases. The higher the axial compression ratio is, the smaller the strain of the beam connection area or the joint core area is, but the higher the strain of the column connection area. The strain values of the beam connection area and the joint core area are less than the yield strain value, indicating that the steel welded connection is feasible.(2) Under cyclic loading, the joint core area of prefabricated steel reinforced concrete frame exterior joint fails in shear or flexural-shear modes diminishingly as the axial compression ratio increases. The prefabricated steel reinforced concrete frame exterior joint performs higher carrying capacity and better ductility compared with the reinforced concrete frame exterior joint. The energy dissipation capacity of the prefabricated steel reinforced concrete frame exterior joint is better due to its better plastic deformation capability. The carrying capacity and stiffness of the prefabricated steel reinforced concrete frame exterior joint decline sharply under higher axial compression ratio, and the ductility factor and energy dissipation of the joint combination decrease as the axial compression ratio increases. The higher the axial compression ratio is, the smaller the strain of the beam and the column connection area or the joint core area is. The strain values of the beam connection area and the joint core area are less than the yield strain value, indicating that the steel welded connection is feasible.(3) In a certain range, the shear-resistance capacity of beam-column joint increases as the axial compression ratio increases, and the axial compression ratio has significant effect on the shear-resistance capacity of beam-column joint.(4) Based on Quasi-static loading tests of prefabricated steel reinforced concrete frame joint combinations, mechanical behavior is analyzed overall. Calculation method of shear resistance and crack resistance are presented. The ratio of calculated values to experimental values ranges from0.93tol.04for shear capacity, and the ratio of calculated values to experimental values ranges from0.95to1.05for crack capacity. |
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