Flexural fatigue analysis of steel fiber-reinforced concrete

The paper presents results of an investigation carried out to study the fat igue strength of steel fiber-reinforced concrete (SFRC). An extensive exper imental investigation was planned in which 127 SFRC beam specimens 100 x 10 0 x 500 mm in size were tested under four-point flexural fatigue loading in an MTS closed loop electrohydraulic universal testing machine. The specime n incorporated three different volume fractions (that is, 0.5 1.0, and 1.5% ) of corrugated steel fibers 0.6 x 2.0 x 30 mm in size. One hundred and eig ht specimens were also tested under static flexure to obtain rite static fl exural strength of different batches of concrete prior to fatigue testing. The test data are used to generate the S-N curves and regression analysis i s used to propose an equation to predict the flexural fatigue strength of S FRC. A probabilistic approach is used to predict the fatigue reliability of SFRC. The fatigue-life distributions of SFRC at a given stress level is sh own to approximately follow the two-parameter Weibull distribution. The S-N relationships have been used to obtain the parameters of the Weibull distr ibution. Design fatigue lives have been obtained for different stress level s for SFRC corresponding to different probabilities of failure.