纤维增强混凝土剪力墙抗震性能试验研究与理论分析

为根本改善混凝土基体的脆性，提高混凝土剪力墙的抗震性能和损伤容限，设计制作6个局部纤维增强混凝土（FRC）剪力墙试件，在试件变形关键部位采用FRC替代普通混凝土，并考虑高轴压比下剪力墙受压钢筋屈曲和受拉纵筋应力集中的问题，在塑性铰区纵向钢筋上设置钢套管，以改善受力钢筋的稳定性和变形性能。通过对悬臂剪力墙试件的拟静力试验，研究此类剪力墙的破坏现象、受力机理和滞回特性，探讨轴压比、FRC区高度、纵筋强度和钢套管长度等因素对墙体变形能力及耗能能力的影响。研究表明，与普通混凝土剪力墙试件相比，塑性铰区采用FRC的剪力墙试件具有较高的损伤容限和变形能力；提高钢筋强度和延性以及在纵筋上设置钢套管，对其抗震性能和耗能能力均具有明显的改善作用。

Experimental and theoretical studies on seismic behavior offiber reinforced concrete shear walls

To overcome the brittleness matrix of concrete essentially and improve the seismic behavior and damage tolerance capacity of concrete shear walls, a set of six fiber reinforced concrete (FRC) shear walls specimens was designed by substituting of normal concrete with FRC with tensile strain-hardening behavior as matrix in deformation-critical locations of reinforced concrete (RC) shear wall. Considering the aspects of compression buckling and tensile stress concentration of longitudinal reinforcement of shear wall under high axial load, an approach was developed to enhance the stability and deformation capacity of structural steel reinforcement by means of steel sleeves that were placed onto the reinforcing bars in the potential plastic region. The failure phenomenon, mechanisms and hysteretic property for the walls were investigated by the quasi-static cyclic tests of the cantilever shear wall units, and the main factors of influencing deformation capacity and energy dissipation capacity in terms of the axial load ratio, height of FRC zone, strength of longitudinal reinforcement and length of steel sleeves were discussed. Results indicate that the proposed FRC shear walls have excellent damage tolerance and deformation capacity as compared with conventional RC specimens, and increasing strength and ductility of longitudinal reinforcement and using steel sleeves can lead to improved seismic behavior and energy dissipation capacity.