【作者】 纪胜敏；

【导师】 于德湖； 张同波；

【作者基本信息】 青岛理工大学 ， 结构工程， 2010， 硕士

【摘要】 混凝土结构的收缩裂缝是学术界和工程应用中长期关注的重要课题。本文从制约混凝土裂缝发展的视角,针对混凝土收缩变形的大小,混凝土力学行为,以及混凝土变形的约束程度等方面展开了试验研究及理论分析,从而深入地认识收缩裂缝的发展机理,并在此基础上,结合混凝土结构的特点提出有效的裂缝控制措施,以满足工程应用需要。首先,本文介绍了几种常用的混凝土干缩及自收缩计算模型,从原理和适用范围分别进行了综合评价,结合混凝土的微观结构探讨了混凝土收缩变形机理及内部湿度场与宏观变形的联系。其次,考虑到混凝土结构构件的整体变形不便于测量,基于高斯积分函数的原理,提出利用高斯积分布点的方式测量混凝土结构构件变形的方法。将高斯积分函数应用于混凝土结构构件的变形计算中,再根据应变的定义,推算混凝土随龄期变化的应变值。再次,进行足尺寸构件试验和现场试验。足尺寸构件试验通过架设百分表和按高斯积分点布点的方法获得了素混凝土梁及钢筋混凝土梁的总应变量,并把试验值进行回归分析,通过截面不同高度不同试验值的回归结果,给出了约束沿混凝土梁截面不同高度的变化规律。然后,给出考虑配筋影响的收缩计算公式,通过素混凝土梁和钢筋混凝土梁的试验值,验证文献所给的配筋影响系数是否可取。最后,基于混凝土结构的约束应力的理论分析,通过北村新工程现场试验进行地下室底板约束应力的计算,验证王铁梦提出的计算方法是否可以应用于实际工程,并通过北村新工程地下室底板收缩应力计算,对地下室底板进行抗裂测评。同时,总结足尺寸构件试验和北村新工程试验中的测试方法的优缺点,提出改进后的测量混凝土结构收缩的试验方法。更多还原

【Abstract】 The shrinkage cracking of concrete is an important problem in the academic circles and structure engineering.From the point of restraint for the shrinkage cracking,the experimental and theoretic studies are further conducted on the three basic factors ( the shrinkage strains of concrete,the mechanical properties of concrete,and the degree of restraint for concrete ) . So,the mechanism of the shrinkage cracking is deeply studied,and the effective control measures of the shrinkage cracking for concrete structure are supposed to reply the need of the engineering.Frist,several common calculation model of dry shrinkage and Self-shrinkage about concrete were introduced in the paper, and make comprehensive evaluation on these model from principle and applicable scope, combined with Micro-Structure Analysis of Concrete, the mechanical of concrete shrinkage and relationship between humidity field and macroscopic deformation are investigated.Second, considering the deformation of concrete structure component to measure, based on the principle of gaussian integral function, this paper puts forward the way of measuring the gaussian integral covers the deformation of the concrete structural components. The gaussian integral function is applied on concrete structural components to measure deformation, and calculate the variation of tensile strength as age change according to the definition of strain of concrete.Third, sufficient size component test and field test was conducted. The strain of sufficient size plain concrete and reinforced concrete was measured by the way of erecting batches and decorating measuring-point according to the gaussian integral, and the total value of regression analysis. The constraints along the concrete beam variation of different heights is given through through the cross-section regression of different experimental results along different heights. Then, the formula is given considering the reinforcement of the contraction. Through the plain concrete beams and reinforced concrete beam test value to verify that the reinforcement of the literature of the validity coefficient. At last, start with the theoretical analysis of concrete structures restraint stress. Wang Tie-meng proposed method which prove to be right and can be applied to practical engineering. Then, the crack on the basement floor is evaluated through calculating shrinkage stress of North Village New works basement floor. Meanwhile, Summarize advantages and disadvantages of sufficient size component test and field test and puts forward the improvement measure of concrete structure shrinkage test method.更多还原