Investigation on the relationship between the steel fibre distribution and the post-cracking behaviour of SFRC

Abstract

The post-cracking behaviour of steel fibre reinforced concrete (SFRC) are significantly influenced by the distribution of steel fibre in the concrete, while steel fibre distribution is further affected by wall-effect and fibre content. A series of three-point bending tests, cube splitting tests, and Brazilian splitting tests were conducted to analyze the influence of wall-effect and fibre content on the post-cracking tensile strength of SFRC. Furthermore, the influence of wall-effect and fibre content on fibre distribution was determined by conducting inductive tests on cubic SFRC specimens. To directly determine the relationship between fibre content and orientation, and the post-cracking mechanical properties of SFRC, this paper proposes a multi-axial cube splitting test (MCST test). Furthermore, this paper also proposes a method which utilizes the MCST test to measure fibre orientation based on the relationship between post-cracking peak load and toughness, and steel fibre orientation. Therefore, MCST method can be adapted for using with any type of fibre reinforced concrete, while the inductive test can only be used for concrete that is reinforced with metallic fibre. The MCST method is verified by comparing the similarity of the fibre orientations that were obtained using the inductive tests and MCST tests.