Investigation into the effect of fibre distribution on the post-cracking tensile strength of SFRC through physical experimentation and numerical simulation

Abstract

Steel Fibre Reinforced Concrete (SFRC) is a two-phase heterogeneous material that is composed of steel fibres and a concrete matrix, whose specimen toughness, residual strength, and impact resistance is dependent on the distribution of steel fibres within the concrete matrix. Thus, this paper has elected to study the effects of fibre distribution on the post-cracking tensile strength of cubic SFRC specimens at the mesoscopic level using physical experiments and numerical simulations. The first step of analyzing the effects of fibre distribution must invariably be the determination of fibre distribution itself; therefore, inductive tests were conducted to determine the distribution of fibres in cubic SFRC specimens of varying fibre contents. A three-dimensional steel fibre distribution model was generated in MATLAB according to the steel fibre distribution that was obtained from the inductive tests. Physical multi-axial cube splitting tests (MCST tests) were carried out on all cubic SFRC specimens to study the effects of fibre content and orientation on the post-cracking tensile strength of SFRC. Afterwards, the three-dimensional steel fibre distribution model was imported from MATLAB into ABAQUS, a finite element software, to establish the SFRC mesoscale model, wherein the assignment and calibration of model parameters were based on the results of the MCST tests. Finally, simulated MCST tests were carried out using the mesoscale SFRC models. Comparative analyses between the mesoscale SFRC numerical simulation results and the experimental results show that both agree well with each other, which verifies the validity of the numerical model. This paper's verified model has a broad range of applications, which include a variety of scenarios that range from simple mechanical tests to complex steel fibre reinforced concrete structures.