Fatigue life of concrete beams that are overlaid or underlaid with FRC is analyzed with a frac- ture mechanics based model. The problems analyzed are the cases for concrete beams overlaid or underlaid with hooked-end steel fiber reinforced concrete. For…
Fatigue life of concrete beams that are overlaid or underlaid with FRC is analyzed with a frac- ture mechanics based model. The problems analyzed are the cases for concrete beams overlaid or underlaid with hooked-end steel fiber reinforced concrete. For both of overlaid and underlaid beams, three cases of beam heights, three values of fiber volume fraction, and the five levels of the FRC thickness ratio are exam- ined. In the case of overlay, resulting fatigue crack growth plots and theoretical S-N diagrams show that nei- ther small dosage of fibers nor thin FRC repair layer is effective to suppress the fatigue crack growth. On the other hand, in the case of underlay, fatigue crack growth plots show the suppression of fatigue crack growth in the early stage, and theoretical S-N diagrams show improvements in fatigue strength. Overall, overlay and underlay exhibit different characteristics in the role of fatigue crack tip shielding.