锈蚀钢绞线混凝土黏结滑移本构模型研究

Bond-Slip Constitutive Model of Corroded Steel Strand Concrete

针对锈蚀钢绞线混凝土黏结滑移性能问题,利用拉拔试验分析不同锈蚀率及保护层厚度对试件破坏形态、裂缝数量及宽度、荷载-位移曲线形状、极限黏结强度和极限相对滑移的影响,建立了改进后的黏结滑移本构模型。研究结果表明:锈蚀率相同时,随着保护层厚度增大裂缝数量和宽度呈减小趋势,极限黏结强度及极限相对滑移量与保护层厚度呈线性正相关;同等保护层厚度下,裂缝数量随锈蚀率的增加基本不变,裂缝宽度随锈蚀率增加而增大;极限黏结强度及极限相对滑移量随锈蚀率增大呈线性减小趋势;仿真结果显示,提出的锈蚀钢绞线混凝土黏结滑移本构模型可以较好地描述锈蚀钢绞线混凝土试件黏结滑移退化行为。

Aiming at the problem of bond-slip performance of corroded steel strand concrete,the influence of different corrosion rate and cover thickness on the failure mode,number and width of cracks,shape of load-displacement curve,ultimate bond strength and ultimate relative slip were analyzed by the pull-out test,and the improved bond slip constitutive model was established.The research results show that when the corrosion rate is the same,the number and width of cracks tend to decrease with the increase of the thickness of the protective layer,and the ultimate bond strength and ultimate relative slip are linearly and positively correlated with the thickness of the protective layer.Under the same thickness of protective layer,the number of cracks is basically unchanged with the increase of corrosion rate,and the width of cracks increases with the increase of corrosion rate.The ultimate bond strength and ultimate relative slip decrease linearly with the increase of corrosion rate.The simulation results show that the proposed bond-slip constitutive model of corroded steel strand concrete can better describe the bond-slip degradation behavior of corroded steel strand concrete specimens.