Flexural fatigue strength prediction of hybrid-fibre-reinforced self-compacting concrete

Mathematical models were developed for predicting the flexural fatigue strength of hybrid-fibre-reinforced self-compacting concrete based on fatigue test results. Steel and polypropylene fibres were used at 1% total mix volume in various proportions. About 250 flexural fatigue tests and 90 static flexural tests were carried out. The fatigue-life data obtained were analysed to determine the relationship between the stress level, the number of cycles to failure and the probability of failure. It was found that the relationship can be represented reasonably well graphically by a family of curves. The experimental coefficients of the fatigue equations were calculated from the fatigue test data to obtain the analytical curves. The 2 million cycle fatigue strength of the concrete mixes was also calculated from the curves.