锈蚀钢筋混凝土梁斜截面抗剪承载力计算分析
发布时间：2019-03-18 11:49
【摘要】：钢筋混凝土结构的耐久性问题受到工程领域内世界各国的广为关注,而钢筋的锈蚀是影响结构耐久性的最主要因素,同时也是其结构最为普遍的病害之一。钢筋发生锈蚀后,其截面面积减小、力学性能退化、钢筋与混凝土间的粘结性能降低、混凝土保护层开裂,易造成受弯构件发生斜截面剪切脆性破坏,其后果比正截面破坏更加严重。目前,国内外对锈蚀钢筋混凝土构件正截面承载力进行了大量研究并取得了较好的成果,而对构件斜截面抗剪承载力研究较少。由于箍筋直径、保护层厚度均比较小,箍筋的锈蚀程度一般比较严重,从而更大程度上影响了斜截面抗剪承载力。本文在相关试验数据的研究基础上,针对锈蚀的有腹筋的钢筋混凝土简支梁,进行了其斜截面抗剪承载力计算方法的分析以及研究,主要研究内容分为以下几个方面：(1)对钢筋混凝土结构中钢筋锈蚀机理以及锈蚀过程进行了归纳和总结,重点介绍了引起钢筋锈蚀的主要影响因素。(2)对目前存在的抗剪模型以及理论方法,并详细介绍了桁架模型理论、极限平衡理论、塑性理论等模型理论,并将各个模型的优缺点做了对比。(3)本文基于桁架-拱模型的抗剪理论,通过分析得到改进的桁架-拱模型抗剪公式,将计算结果与试验结果进行对比分析,验证了该方法。(4)对于锈蚀梁的抗剪承载力计算,在本文抗剪承载力计算式上,引入钢筋锈蚀后的屈服强度以及实际面积,同时考虑锈蚀造成的混凝土截面损伤、粘结强度的减小以及销栓作用的退化,收集相关数据进行线性回归,得到了关于箍筋锈蚀率的修正系数,从而建立了锈蚀梁的抗剪承载力计算公式。同时将本文计算方法与已有锈蚀梁的抗剪承载力计算方法进行了对比分析,从整个数据而言,该公式计算结果与试验结果能较好地吻合。
[Abstract]:The durability of reinforced concrete structures has been paid more and more attention all over the world in the field of engineering, and the corrosion of steel bars is the most important factor that affects the durability of structures, and it is also one of the most common diseases of reinforced concrete structures. After corrosion, the cross-section area of the steel bar decreases, the mechanical property degrades, the bond performance between the steel bar and the concrete decreases, the concrete protective layer cracks, and the bending member is prone to shear brittleness failure of the inclined cross-section. The consequences are more severe than the normal section damage. At present, a great deal of research has been done on the bearing capacity of normal section of corroded reinforced concrete members at home and abroad, and good results have been obtained, but the research on shear capacity of inclined section of members is less. Because of the diameter of stirrups and the thickness of protective layer, the corrosion degree of stirrups is usually serious, which greatly affects the shear capacity of inclined cross-section. On the basis of relevant experimental data, this paper analyzes and studies the calculation method of shear capacity of inclined section of corroded simply supported reinforced concrete beams with web reinforcement. The main research contents are as follows: (1) the corrosion mechanism and process of reinforcement corrosion in reinforced concrete structure are summarized and summarized. The main influencing factors of steel bar corrosion are introduced in detail. (2) the existing shear models and theoretical methods are introduced in detail, and the truss model theory, limit equilibrium theory, plastic theory and other model theories are introduced in detail. The advantages and disadvantages of each model are compared. (3) based on the shear theory of truss-arch model, the improved shear formula of truss-arch model is obtained through analysis, and the calculated results are compared with the experimental results. The proposed method is verified. (4) for the calculation of shear capacity of corroded beams, the yield strength and actual area of steel bars after corrosion are introduced in this paper, and the damage of concrete section caused by corrosion is also considered. With the decrease of bond strength and the degradation of pin action, the relevant data are collected for linear regression, and the correction coefficient of corrosion rate of stirrups is obtained, thus the formula for calculating the shear capacity of corroded beams is established. At the same time, the calculation method in this paper is compared with the existing calculation method of shear capacity of corroded beams. From the whole data, the calculated results of this formula are in good agreement with the experimental results.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU375.1
本文编号：2442836
[Abstract]:The durability of reinforced concrete structures has been paid more and more attention all over the world in the field of engineering, and the corrosion of steel bars is the most important factor that affects the durability of structures, and it is also one of the most common diseases of reinforced concrete structures. After corrosion, the cross-section area of the steel bar decreases, the mechanical property degrades, the bond performance between the steel bar and the concrete decreases, the concrete protective layer cracks, and the bending member is prone to shear brittleness failure of the inclined cross-section. The consequences are more severe than the normal section damage. At present, a great deal of research has been done on the bearing capacity of normal section of corroded reinforced concrete members at home and abroad, and good results have been obtained, but the research on shear capacity of inclined section of members is less. Because of the diameter of stirrups and the thickness of protective layer, the corrosion degree of stirrups is usually serious, which greatly affects the shear capacity of inclined cross-section. On the basis of relevant experimental data, this paper analyzes and studies the calculation method of shear capacity of inclined section of corroded simply supported reinforced concrete beams with web reinforcement. The main research contents are as follows: (1) the corrosion mechanism and process of reinforcement corrosion in reinforced concrete structure are summarized and summarized. The main influencing factors of steel bar corrosion are introduced in detail. (2) the existing shear models and theoretical methods are introduced in detail, and the truss model theory, limit equilibrium theory, plastic theory and other model theories are introduced in detail. The advantages and disadvantages of each model are compared. (3) based on the shear theory of truss-arch model, the improved shear formula of truss-arch model is obtained through analysis, and the calculated results are compared with the experimental results. The proposed method is verified. (4) for the calculation of shear capacity of corroded beams, the yield strength and actual area of steel bars after corrosion are introduced in this paper, and the damage of concrete section caused by corrosion is also considered. With the decrease of bond strength and the degradation of pin action, the relevant data are collected for linear regression, and the correction coefficient of corrosion rate of stirrups is obtained, thus the formula for calculating the shear capacity of corroded beams is established. At the same time, the calculation method in this paper is compared with the existing calculation method of shear capacity of corroded beams. From the whole data, the calculated results of this formula are in good agreement with the experimental results.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU375.1
【参考文献】
相关硕士学位论文 前1条
1 李娟;HRB500级箍筋混凝土梁斜截面受力性能试验研究[D];湖南大学;2007年
，本文编号：2442836
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