STUDY OF THE FATIGUE PERFORMANCE AND DAMAGE MECHANISM OF STEEL FIBER REINFORCED CONCRETE

摘要

In this paper, the effect of the volume fraction of steel fiber, amount of silica fume and their composite on the fatigue performance and the mechanism of fatigue damage are investigated. The fatigue equations of steel fiber reinforced concrete and reinforced high strength concrete are put forward. Testing results show fully that the effect of volume fraction and length diameter ratio on fatigue performance of concrete is extremely prominent. When silica fume, steel fiber and their composite are added to high strength concrete, the double effect of interfacial strengthening and space superimposing of fiber-cement matrix and aggregate- cement matrix is produced, the interfacial structure and character are improved, the process of strengthening, vanishing and re-strengthening of interface is caused, the dimension and the amount of crack sources are reduced, thus putting off the crack extension and propagation and delaying the process of fatigue damage, prolonging evidently the fatigue life.