局部采用纤维增强混凝土剪力墙压弯性能研究

以提高钢筋混凝土剪力墙压弯性能为目的,将纤维增强混凝土(FRC)应用于剪力墙塑性变形关键部位。通过对6个高轴压比FRC剪力墙抗震性能试验结果的研究,并基于对FRC受力机理和钢套管影响的考虑,提出了与墙体开裂状态、屈服状态、峰值状态和极限状态相应的FRC剪力墙弯矩-曲率计算方法,并对影响其各阶段压弯荷载公式的因素进行了分析。研究表明,该文建议的压弯构件弯矩-曲率计算公式能较为准确地描述剪力墙各阶段的荷载-变形关系,计算值与试验值吻合较好;与普通混凝土剪力墙相比,考虑FRC材料的受拉性能,能提高正常使用状态下剪力墙截面的抵抗弯矩,减小墙体截面变形需求;显著改善承载能力极限状态下墙体的变形能力和损伤容限。

THE COMPRESSION-BENDING BEHAVIOR OF SHEAR WALL WITH FIBER-REINFORCED CONCRETE IN BOTTOM REGION

With the purpose of enhancing the behavior of reinforced concrete (RC) shear wall subjected to compression bending,the fiber-reinforced concrete (FRC) was applied in the critical locations of shear walls suffering inelastic deformation to replace normal concrete. Considering the high strain-hardening in tension behavior of FRC and the effect of steel sleeves, experimental results of six FRC shear walls with high axial load ratio were analyzed, and a simple calculation method for moment-curvature of the eccentrically compressed FRC shear walls was presented corresponding to the four damage states of walls, including cracking, yielding, peak loading and ultimate loading, and the main factors influencing the compressive bending behavior of shear walls at different states were discussed. It is shown that the proposed moment-curvature calculation method can be used to predict the load-deformation relationship of FRC shear walls accurately. Compared with conventional RC shear walls, the application of FRC, which has high tension capacity, increases moment resistance, as well as reduces deformation demand of wall cross-section at the limit state of serviceability. The combination of the ductile FRC and steel reinforcement improves deformation capacity and damage tolerance at the ultimate limit state.