Failure mechanism of fibre reinforced concrete under splitting test using digital image correlation

The study aims at analysing the fracture mechanism of steel fibre-reinforced concrete in tensile splitting using digital image correlation. The work also aims to exam the influence of both the steel fibre addition and the compressive strength on the behaviour of fibre-reinforced concrete (FRC) in splitting tension test. Cylindrical concrete specimens having 110 mm diameter and 220 mm height were subjected to splitting tests. The cylinders specimens were made with different concrete types and reinforced with steel fibres of two aspect ratios (65 and 80) using three volume fractions (0, 0.5 and 1 %). The types of concretes with various compressive strengths and rheology consisted of an ordinary concrete, a self-compacting concrete and a high strength concrete. The test results revealed the existence of two failure mechanisms; the first one is associated with a central unique crack, whereas the second is related to a secondary cracks initiated at the edges of the test specimens after the main one. Moreover, correlations between the main mechanical properties were developed. The results show that the fibres and the compressive strength of concrete have a significant effect on the behaviour of FRC in splitting. The fibres were more effective in high strength matrix by increasing both the ultimate load and the ductility. This increase, which reached up to 70 %, is attributed to a better quality bond between the steel fibres and the matrix.