Failure Mechanism of Concrete under Fatigue Compressive Load

In this paper, the behavior of concrete under static and fatigue compressive load is studied. Cylindrical specimens were subjected to static cyclic and constant amplitude fatigue loading. The static cyclic tests were performed by unloading and reloading the specimen at three different points in the postpeak period of the static loading response. Low cycle, high amplitude fatigue tests were performed to failure using three load amplitudes. It is found that under the term of structural compliance the static compressive response of concrete can be used as an envelope for the fatigue failure compressive response. The change rate of stiffness or compliance under fatigue loading follows a two-stage process: a deceleration stage followed by an acceleration stage up to failure. The failure mechanisms for both static and fatigue loading are explained by the band damage zone model and found to be consistent in the term of an inelastic displacement. The results agree well with the previous research work.