PREDICTION OF MEAN AND DESIGN FATIGUE LIVES OF STEEL FIBROUS CONCRETE USING S-N RELATIONSHIPS

The paper presents a study on the fatigue strength of steel fibre reinforced concrete (SFRC) containing different volume fractions, aspect ratios and types of steel fibres, for various levels of the fatigue stress. The fatigue test data available in literature has been used for analysis. The test data is used to generate the S-N curves and an Equation is proposed by regression analysis to predict the flexural fatigue strength of SFRC. A probabilistic approach is used to predict the fatigue reliability of SFRC. The fatigue-life distributions of SFRC at a given stress level, is shown to approximately follow the two-parameter Weibull distribution. The S-N relationships have been used to obtain the parameters of the Weibull distribution. Mean and Design fatigue lives have been computed for different stress levels for SFRC with different combinations of fibres, corresponding to different probabilities of failure.