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为研究钢筋混凝土结构锈蚀后的力学性能和抗力退化规律,基于RC梁加速锈蚀试验结果,首先综合考虑均匀锈蚀和点蚀同时发生的影响,对钢筋截面面积的时变模型进行分析,其次探讨裂缝宽度与氯离子扩散系数及RC梁抗力的关系,随后考虑受拉主筋锈蚀不均衡的影响,对结构抗力计算模型进行讨论,最后基于材料性能和结构尺寸的空间变异性,建立RC梁抗力时空退化模型,并对桥梁服役100 a后的抗力进行预测.研究发现:当考虑各参数的空间变异性时,不考虑裂缝影响得到的抗力值比考虑裂缝影响得到的抗力值高了9.91%;考虑各参数空间变异性时的抗力值比不考虑时下降了14.68%;适当的选取波动系数和单元尺寸对考虑结构各参数的空间变异性十分重要;潮汐区和浪溅区环境下结构的剩余抗力分别为初始抗力的43.23%和36.45%,较海岸线大气区环境下的抗力值分别下降了6.73%和21.35%,因此在结构服役期间,应尽量做好防腐措施,减少氯离子侵蚀对结构耐久性的破坏.
In order to study the mechanical properties and resistance degradation of reinforced concrete structure after corrosion, based on the accelerated corrosion test results of RC beams, the time-varying model of the cross-sectional area of reinforced concrete is firstly analyzed considering the simultaneous rust and pitting. Width, chloride ion diffusion coefficient and RC beam resistance, and then considering the unbalanced corrosion of the main reinforcement, the structural resistance calculation model is discussed. Finally, based on the spatial variability of material properties and structural dimensions, Model and the resistance of the bridge after 100 years of service is predicted.The study found that when taking into account the spatial variability of the parameters, the resistance value obtained without considering the influence of the crack is 9.91% higher than the resistance value obtained by considering the crack effect; The resistance value of parameter space variability is decreased by 14.68% when it is not considered. Appropriate selection of the coefficient of variation and unit size is very important to consider the spatial variability of the parameters of the structure. Residual resistance of the structure in tidal zone and splash zone respectively 43.23% and 36.45% of the initial resistance, respectively, representing a decrease of 6.73% and 21% respectively over the coastal area’s atmospheric environment. 35%. Therefore, during the period of service of the structure, anticorrosive measures should be done as much as possible to reduce the damage to the durability of the structure caused by chloride ion erosion.