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The paper presents results of an investigation carried out to study the flexural fatigue strength of steel fibre reinforced concrete (SFRC). An experimental investigation was planned in which 180 SFRC beam specimens of size 100 × 100 × 500 mm were tested under four-point flexural fatigue loading. The specimen incorporated three different volume fractions i.e. 1.0%, 1.5% and 2.0% of corrugated steel fibres. Each volume fraction incorporated mixed steel fibres of size 0.6 × 2.0 × 25 mm and 0.6 × 2.0 × 50 mm in different proportions. The fatigue-life distributions of SFRC at a given stress level, is shown to approximately follow the two-parameter Weibull distribution. The parameters of the Weibull distribution for fatigue life of SFRC have been obtained from S – N relationships. Mean and design fatigue lives have been obtained for SFRC with different fibre volume fractions, each volume fraction containing different fibre mix proportions. It has been observed that SFRC having 1.0% fibre content with fibre mix proportion of 35% 50 mm + 65% 25 mm long fibres exhibits the highest mean and design fatigue lives.

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Results of an investigation of the probability distributions and flexural fatigue performance of self-compacting concrete beams are presented. The fatigue tests were carried out with a 100 kN capacity closed-loop servo-controlled actuator on 100 × 100 × 500 mm size beam specimens under four-point flexural loading. The static flexural strength of the self-compacting concrete was determined before the fatigue tests. The test data have been used to examine the distribution of fatigue life of self-compacting concrete at different stress levels. It has been shown that the statistical distribution of fatigue life of self-compacting concrete at a given stress level can be modelled by the two-parameter Weibull distribution with its distribution parameters estimated by different methods of analysis. The results indicate that there was lower variability in the distribution of fatigue life of self-compacting concrete compared to that of normally vibrated concrete. The fatigue life data have also been presented in the form of an S–N diagram and the two-million-cycles fatigue strength of self-compacting concrete has been found to be marginally higher than that of normally vibrated concrete. The fatigue life data of normally vibrated concrete used for comparison were obtained from the literature.