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

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.