Effect of matrix strength on pull-out behaviour of hooked steel fibre-reinforced cementitious composites

This paper investigates the effect of matrix composition and its mechanical properties, mainly compressive strength, on the pull-out response of hooked steel fibres. A limited experimental study was also conducted on silica fume to cement and sand to cement ratios to gain further insight into the effect of matrix composition. The experimental program involved hooked steel fibres embedded in six different matrices. Test results have shown that pull-out behaviour of hooked steel fibre is influenced by the matrix composition and its compressive strength. All the fibres were pulled out from matrix without any fibre rupture. Hooked fibres produce a higher pull-out load with a higher compressive strength matrix and leads to significant enhancements in both pull-out load and pull-out energy in higher strength matrix than in lower strength matrix. Based on the result, all aspects of pull-out comprising pull-out load, pull-out energy, and equivalent bond strength were improved as the silica fume to cement ratio increased.