不同温度下混凝土抗拉疲劳性能试验研究

EXPERIMENTAL INVESTIGATION OF FATIGUE BEHAVIOR OF CONCRETE UNDER CYCLIC TENSION LOADING AT DIFFERENT TEMPERATURES

  • 摘要: 进行了不同温度下混凝土在等幅重复荷载作用下的抗拉疲劳性能试验研究,分析了不同温度下砼抗拉疲劳强度、刚度、变形规律,建立了相应的疲劳方程及考虑温度影响的统一疲劳方程,并将常温下的砼疲劳性能试验结果同其他研究者的结果作了比较.给出了纵向总应变、割线模量的经验公式,及其第二阶段总应变增长率、割线模量衰减率分别与疲劳寿命的关系式.研究结果,为高温环境下受重复循环荷载作用的砼结构设计和分析提供了试验依据.

     

    Abstract: In this paper, the fatigue behavior of concrete in uniaxial tension under cyclic loading of constant amplitude at different temperatures is investigated experimentally. The variations of tensile fatigue strength, stiffness, and deformation are analysed. The fatigue behavior of concrete at normal temperature(20℃)is compared with other available results. The fatigue equation at certain temperature is established from which the unified fatigue equation accounting for different temperatures is derived. The two empirical expressions of the total longitudinal strain and the secant modulus in terms of the number of loading cycles are given. In addition, the relationships of the incremental rate of the total strain and the decay rate of the secant modulus with the fatigue life in the main stage, i.e., the second stage of the development of strain, are obtained respectively, from which the fatigue life of concrete can be predicted. The results of present investigation offer the basis for the design and analysis of concrete structures.

     

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