Influence of fibre-aggregate interaction on some properties of steel fibre reinforced concrete

In the practical applications of fibre reinforced concrete, particularly for load-bearing purposes, it is desirable to incorporate coarse aggregates for economic and other reasons. Tests are reported in this paper in which the fibre-aggregate interaction is related to the properties of steel fibre concrete both in the fresh and hardened states. It is shown that compactibility, flexural and compressive strengths are reduced progressively by the presence of coarse aggregates. From the test results, a mix design for fibre concrete containing coarse aggregates to produce twice the flexural strength of the unreinforced matrix without bundling of fibres is presented. The data presented on flexural strength show good agreement with theory.