Papers by Keyword: Composite Frame Column

Abstract: The shear behaviors of steel reinforced high strength and high performance concrete (SRHSHPC) composite frame columns are studied through the test on a number of SRHSHPC specimens with grade of concrete strength varied from C80 to C120 subjected to constant axial compression and cyclically varying horizontal load. Four influencing factors, namely, shear span ratio, axial compression ratio, stirrup ratio and concrete strength, are taken into consideration in the test, and strain gauges are respectively placed on steel web, stirrups as well as reinforcement bars to study the shear mechanism of SRHSHPC composite columns. According to test results, the shear failure patterns and shear mechanism of the specimens are discussed. By analyzing the contribution of the steel web, concrete, stirrups and reinforcement bars to the shear capacity, the shear mechanism of the SRHSHPC composite columns is figured out. Therefore, the influence of shear span ratio, axial compression ratio, stirrup ratios and concrete strength on shear behaviors of the SRHSHPC frame columns is clear. Finally, concrete truss model and principle of accumulation are applied to discuss the shear capacity and a calculation model for shear strength of the SRHSHPC composite columns is established. It is indicated that the shear behaviors of the SRHSHPC frame composite columns are excellent, and the calculated results of shear strength have good conformity with test results.

Abstract: Based on experimental investigation under low cyclic reversed loading, the seismic behaviors and seismic damage model for steel reinforced high strength and high performance concrete (SRHSHPC) composite frame columns are studied. Several existing seismic damage models are firstly presented and their characteristics are comparatively analyzed. From the test results of low cyclic reversed loading, the variation history of cumulative dissipated hysteretic energy of the SRHSHPC composite frame columns under different loading cycle levels is figured out, and the influence of axial compression ratio, shear span ratio, stirrup ratio and concrete strength on the cumulative dissipated hysteretic energy is also discussed. The damage index of the SRHSHPC composite frame columns is compared according to the existing seismic damage models, and the seismic damage model adapted for the SRHSHPC composite frame columns is established. According to the variation history of the damage index under different loading cycle levels, the rule of damage development for the SRHSHPC composite frame columns is proposed. The influence of axial compression ratio, shear span ratio, stirrup ratio and concrete strength on the damage development is also discussed. The results indicate that the seismic behaviors of the SRHSHPC composite frame column are outstanding, and the seismic damage model could give a quantitative description for damaging process of the samples, which is reference for establishing more rational damage criteria for the SRHSHPC earthquake-resistant composite structure.