Study on Fatigue Response of Concrete and Its Effect on Life-Cycle Behavior of Concrete Structures

Abstract

AbstractThe life-cycle performance of concrete structures is significantly affected by fatigue response of concrete under cyclic or repetitive loading conditions. Different structures such as bridges, buildings and industrial structures, are subjected to cyclic loading, at different stress levels. The deterioration of the structure and its maintenance requirements would depend on the fatigue effects induced in the material under cyclic loading. In this context, the present study evaluates the fatigue response of M40 concrete at different stress levels under cyclic loading. Efforts are also made to compare the performance of conventional concrete (M40) with high strength concrete (M70). Low frequency cyclic loading has been performed on cylindrical specimen of M40 concrete at three different stress levels, viz., 60, 75 and 90% of σc, where σc is the compressive strength of cylindrical specimen. The response of M40 and M70 concrete has also been compared at 75% stress levels. From the study, it can be inferred that the fatigue life of concrete is inversely proportional to the stress level for cyclic loading. As stress level reduces, the failure is observed to be more brittle in nature. For the same stress level, high strength concrete (M70) survives lower number of cycles and exhibits relatively brittle failure as compared to M40 concrete. It can be concluded from the study that based on fatigue response of concrete, degradation in its properties and residual strength for further life can be evaluated.KeywordsFatigueConcrete structuresStiffness degradationLife cycleStress–strain responseCyclic loading