Study of fatigue performance in a pavement concrete mix reinforced with steel fibers

Abstract

The behavior in flexural fatigue tests of concrete containing metal fibers has not been extensively studied. Therefore, this study aims at determining the effects of incorporating metal fibers in concrete paving on flexural fatigue tests. A concrete mix was designed with modulus of rupture of 4.1 MPa at 28 days, which was added with steel fibers of 35 mm long and 0.5 mm in diameter in 3 proportions: 20 kg/m3 , 40 kg/m3 and 80 kg/m3 and left to a non-corresponding control mixture addition. Fatigue tests were performed on 68 specimens of 100 x 100 x 350 mm, at a frequency of 8 Hz, and stresses between 80% and 90% of the modulus of rupture of each mixture. The Weibull probability distribution was used to calculate the fatigue curves with different failure probabilities. For the stress ranges studied, the fatigue life did not increase in the mix with fiber content of 20 kg/m3 , but it did increase by 6% to 40 kg/m3 (0.5%) and 25% to 80 kg/m3 (1%), compared with the control mixture.