高强钢筋高强混凝土剪力墙抗震性能试验

Seismic Experiments for High Strength Concrete Shear Walls Reinforced with High Strength Rebars

目的研究高强混凝土剪力墙的抗震性能、破坏形式和机理.方法通过在剪力墙中配置高强钢筋,利用高强钢筋高强度、低松弛、强握裹力以及良好塑性性能等特点,增强对高强混凝土的约束,提高高强混凝土剪力墙的承载和变形能力.通过5片高强混凝土剪力墙试件的拟静力试验,研究不同的混凝土强度、轴压比和剪跨比等参数对其抗震性能的影响.将1280MPa预应力钢棒作为箍筋和纵筋配置在剪力墙的边部约束构件(暗柱)以及墙体的分布钢筋中.通过对比研究配置高强钢筋对高强混凝土剪力墙抗震性能的提高效果.结果明确了高强混凝土剪力墙的不同破坏形态和过程,得出了影响高强混凝土剪力墙抗震性能的主要因素和影响规律.位移延性系数可达3.9,满足结构抗震要求.结论试验结果证明在高强混凝土中合理适当地配置高强钢筋,可增强其变形能力.

Seismic performances of high strength concrete shear walls reinforced with high strength rebars were experimentally developed in the paper. Behaviors and modality of five specimens were experimentally researched under pseudo static tests. The high strength rebars were used as stirrups and partial longitudinal reinforcements in order to effectively restrict the core concrete in both end columns and central parts of the shear walls. A three-dimensional compression state of the concrete was generated to increase the ductility of the walls. In the tests, the influencing factors such as the strength of concrete, axial compression ratio and shear span ratio, which influenced the strength and deformation properties of the walls, were experimentally examined. The hysteretic loops and skeleton curves of the five specimens were empirically analyzed and compared. From the analysis of the hysteretic loop area, the energy dissipating capacities of the proposed shear walls were experimentally determined. The ductility of the shear walls under an earthquake was also discussed by using a coefficiency of ductility. The experimental phenomenon and data analysis showed that both bearing capacity and deformation ductility of the shear walls were effectively increased by using ultra strength rebar as reinforcement. The deformation ductility of the shear walls has reached 3.90, satisfying the needs seismic properties of structure. The failure mechanism of the shear walls was experimentally clarified and the main parameters for strength and deformation calculation were also empirically determined.