FATIGUE DAMAGE IN ULTRA-HIGH PERFORMANCE CONCRETE

Abstract

The application of repeated loads induces crack formation, and the progression of the cracks initiates internal, cumulative damage in concrete that will cause failure. Any material or members can fail much below its yield strength Several models are proposed to depict the fatigue behaviour of fibre and plain reinforced concrete. Some of them are the Fatigue model based on the Weibull function and hinge model. Weibull model is used to describe fatigue deformation of concrete in three stages, another is the hinge model which outlines a simplified and inclusive concept for analysing nonlinear behaviour in concrete exposed to cyclic loading. The Weibull model depends on the amount of deformation that takes place concerning the number of cycles. Here deformation is related to COD. The suggested model may be used to represent the fatigue deformation at a given stress between minimum and maximum fatigue stress, and all of the model parameters have well-defined physical meanings. This model's validity is confirmed by contrasting its output with previously published compressive and flexural fatigue test results. The fatigue life of concrete may be predicted using a deformation-based approach, and the prediction results show that the suggested model can be effectively used to estimate the fatigue life of concrete materials.