近海环境下锈蚀箍筋约束混凝土本构模型

采用人工气候环境模拟技术模拟近海环境，对36组约束混凝土棱柱体试件进行加速腐蚀，开展轴压试验，研究箍筋锈蚀对约束混凝土峰值应力、峰值应变和应力-应变曲线形状的影响. 通过对试验结果的回归分析，得到考虑箍筋锈蚀率影响的混凝土峰值应力和应变修正系数拟合公式，以形状系数作为应力-应变曲线形状参数，基于Mander模型确定考虑箍筋锈蚀率影响的形状系数的计算公式，建立近海环境下的锈蚀箍筋约束混凝土本构模型. 与试验结果对比发现：采用该模型计算得到的各试件峰值应力、峰值应变及应力-应变曲线形状均与试验结果符合较好，表明建立的本构模型能够较准确地反映锈蚀箍筋约束混凝土力学性能，可以用于该环境下的锈蚀RC结构剩余承载力及抗震性能评估.

Constitutive model of confined concrete by corroded stirrups in coastal environment

Thirty-six reinforced concrete prism specimens were subjected to accelerated corrosion tests by artificial climate simulation technique followed by axial pressure tests in order to analyze the influence of stirrup corrosion level on the peak stress, peak strain, and shape of stress-strain curve of the confined concrete. The factor calculation formulas for peak stress and peak strain of corroded reinforce concrete (RC) prism specimens was developed by regression analysis of test data. The shape of the stress-strain curve of the specimens was characterized by shape factor based on Mander's model. Then the confined concrete by corroded stirrups constitutive model in coastal environment was established. The simulation results were compared with the experimental data. Results showed that all the peak stress, peak strain and stress-strain curves shape of the specimens obtained by proposed method agreed well with the experimental data. The established constitutive mode for confined concrete with corroded stirrup can accurately reflect the mechanical performance of corroded RC prism specimen, indicating its adaptiveness for estimating the residual bearing capacity and the seismic performance of corroded RC structure under the coastal environment.