An experimental study on the fatigue failure of steel fibre reinforced concrete at a single fibre level

Abstract

A series of experimental fatigue tests were performed on pre–slipped, hooked–end steel fibre reinforced concrete (SFRC) at a single fibre level. The fatigue tests were conducted at load levels of 50%, 70% and 85%, with the pre–slip varying from 0.6 mm, 1.2 mm, 1.8 mm and 2.5 mm. The tests were loaded at a frequency of 6 Hz, up to two million cycles or until failure. Two types of failure mechanisms were found, namely fibre rupture and fibre pull–out. At low load levels and small pre–slip, there were little to no failures. As the load level and pre–slip increased, fibre rupture became the common failure mechanism. At the highest load level and pre–slip, fibre pull–out was the dominant failure mechanism. The results also showed that the static load–displacement curve formed an envelope for the fatigue pull–out failure. Furthermore, X-ray Computed Tomography (CT) scans were used to validate the various degrees of pre–slip, as well as the failure mechanisms of tested specimens.