锈蚀钢筋混凝土结构的形态演化与服役可靠性研究

This project mainly focused on the performance and morphological evolution, and the service reliability of the corroded reinforced concrete structures. Based on the field investigation of the structure deterioration degree and its spatial distribution, the corroded reinforcement and reinforcement concrete components will be obtained from accelerate corrosion test, and the relationships among the morphological evolution of the corroded reinforcements, the statistical distribution characteristics, and the concrete surface deterioration will then be investigated. The constitutive relationship of corroded reinforcement will be evaluated and the related semi-analytical model will then be obtained. The bond behaviors between corroded reinforcement and concrete will be analyzed and the existing bond constitutive model will be updated. Combined with the corrosion test, the finite element analysis, and the theoretical method, the applicability and the corrections of plane section assumption will be studied; the flexural rigidity and the normal section bearing capacity modified models will be established. Furthermore, the failure mechanism of normal section will be investigated. According to the brittleness and ductility failure mechanism of the components, an analysis model considering the load effect of corroded statically indeterminate bar system will be established. Moreover, incorporated with the normal section bearing capacity model, the statically indeterminate bar failure modes will also be established based on probability judgment. Therefore, the important failure mode will be extracted and the system reliability will then be calculated. The influence of the deterioration locations and the failure mechanism on the time-dependent reliability will also be determined. This investigation will provide scientific basis to the service reliability evaluation, maintenance and strengthening, and life cycle analysis of corroded reinforcement concrete structures.

以锈蚀钢筋混凝土结构为对象，研究其形态和性能演化规律以及服役可靠性问题。基于结构劣化程度与空间分布形态的现场调研结果，通过加速试验获得锈蚀钢筋和钢筋混凝土试件，研究锈蚀钢筋的形态、统计分布特征及其与混凝土表面劣化状况的关联性；试验研究锈蚀钢筋的本构关系并建立相应的半解析模型；试验分析锈蚀钢筋与混凝土的粘结性能，修正现有粘结本构模型；结合锈蚀构件的试验、有限元分析和理论方法，研究平截面假定的适用性和修正方案，建立锈蚀构件的抗弯刚度和正截面承载力修正模型，并据此研究构件正截面的失效机制；针对构件的脆性与延性失效机制，建立锈蚀超静定杆件荷载效应的分析模型并结合正截面承载力分析模型，建立以概率为判据的超静定杆件的重要失效模式库；由此提取结构的重要失效模式并计算系统可靠度；研究劣化部位、失效机制对结构时变可靠度的影响规律。为锈蚀钢筋混凝土结构的服役可靠性评估、维修加固及全寿命分析提供科学依据。

项目研究以钢筋锈蚀为主线，采用现场调研、理论分析、试验研究和数值计算等方法，研究了锈蚀钢筋混凝土结构的形态和性能演化规律以及服役可靠性问题。调研了数10栋既有建筑结构外部环境状况，采集了200余个混凝土芯样并相应进行了基本力学性能和耐久性指标测试分析；研究了水泥基材料孔溶液的离子传输性能及电化学阻抗谱特征的影响因素；建立了锈蚀钢筋本构关系的简约理论模型，探讨了锈蚀钢筋的空间分布形态和统计分布特征，构建了锈蚀钢筋本构关系的有限元模型；研究发展了辨识混凝土构件中钢筋锈蚀损伤状况的方法；研发了钢筋起锈的辨识装置与方法，进行了钢筋起锈时间和速率的试验测试与统计分析；试验研究了不同水压下混凝土渗水量的时变规律及其抗渗性能；进行了海洋大气区、浪溅区和水下多类别海洋腐蚀环境作用及其效应的模拟试验研究；进行了不同轴压比和锈蚀率的钢筋混凝土柱动力性能试验与建模分析，试验研究了锈蚀钢筋混凝土框架的失效机制和破坏模式；研究建立了锈蚀构件正截面承载力修正模型，考虑多种影响因素和钢筋锈蚀分布形态，数字模拟分析了锈蚀钢筋混凝土梁的服役可靠度及其时间演化特征。. 获3项国家发明专利授权和9项实用新型专利授权，获软件著作权登记成果各2项；已发表论文12篇；参与本项目的研究生15名，其中已培养毕业硕士生8名。