【作者】 杭彧；

【导师】 胡白香；

【作者基本信息】 江苏大学 ， 结构工程， 2010， 硕士

【摘要】 钢筋混凝土结构是目前工业与民用建筑中最主要的结构形式,而钢筋锈蚀是影响混凝土结构耐久性的重要因素之一。在锈蚀钢筋混凝土构件中,钢筋锈蚀引起钢筋的截面面积减少和力学性能的变化、混凝土保护层的开裂以及钢筋与混凝土间粘结性能的变化,这些因素均影响着锈蚀钢筋混凝土构件的承载力。本文首先从锈蚀钢筋混凝土本构关系入手,探讨了混凝土与锈蚀钢筋的应力应变关系,以及它们之间的粘结滑移关系,模拟锈蚀单元的选择,并根据混凝土的破坏准则,分析了混凝土结构破坏后裂缝的处理及开裂后的应力软化;其次运用ANSYS中的非线性弹簧单元COMBIN39的刚度变化模拟钢筋和混凝土之间粘结性能的退化,建立4根局部锈蚀钢筋混凝土直梁3根局部锈蚀钢筋混凝土曲线梁的分析模型,研究了不同锈蚀率下局部锈蚀钢筋混凝土梁的受弯性能,并从钢筋及混凝土应力与应变、裂缝开展情况、挠度变化以及钢筋与混凝土相对滑移量等几个方面对计算结果进行分析、讨论;最后从锈蚀钢筋混凝土梁的破坏模式入手,分析其破坏机理与过程,对锈蚀开裂前及锈蚀开裂后钢筋混凝土梁的承载力进行了研究,建立了各自的承载力评估模型。并收集了部分锈蚀钢筋混凝土梁的试验数据,验证了评估模型的合理性。更多还原

【Abstract】 Reinforced concrete (RC) structure is the most important structure in the civil engineering. Damage due to reinforcement corrosion affects the durability of RC structures greatly. Corrosion of reinforcing bar in RC structural elements leads to reduction of the cross-section of the reinforcing bar and change of steel mechanical properties, longitudinal cracking of concrete cover and change of bond strength between steel and concrete. These mentioned factors greatly influence the mechanical behavior and the load carrying capacity of RC structural elements.Firstly, starting from the corrosion of reinforced concrete constitutive relationship, the bond-slip relationship between the corroded steel and concrete and the selection of simulated corrosion cell are discussed. According to the failure criteria of concrete, it discusses the cracks in concrete structures damaged after the treatment and the stress softening after cracking.Secondly, it is studied that the stiffness of nonlinear finite element model COMBIN39 in ANSYS was simulated to analyze corroded reinforced concrete member.Then four localized analysis of corroded reinforced concrete straight beams and three localized analysis of corroded reinforced concrete curved beams are established and studied the flexural properties of corroded reinforced concrete beams at the different partial corrosion rates.Steel and concrete stress-strain, cracking, deflection, the amount of steel and concrete relative slip are studied.Finally, it analyzed the failure mechanism and process from the corroded reinforced concrete beam failure modes. Corrosion cracking of pre-and post-corrosion cracking of the bearing capacity of reinforced concrete beams has been studied and established their own carrying capacity assessment model. Collected some of the corroded reinforced concrete beam test data and validated of the evaluation model is reasonable.更多还原