Estimation of the fracture parameters of macro fiber-reinforced concrete based on nonlinear elastic fracture mechanics simulations

Abstract

Integration of macro synthetic fibers within the concrete mixture provides residual tensile strength and toughness characteristics. Majority of existing studies in this regard focus on the impact of fibers on improving mechanical properties and durability without considering fracture mechanics parameters: energy release rate (GI) and stress intensity factor (KI). Accordingly, this paper investigates the fracture behavior of concrete incorporating macro-synthetic fibers with monofilament configuration. Nonlinear elastic fracture mechanics simulations were carried out using ABAQUS with proper validation based on experimental test results conducted according to the ASTM C1609 standards. The results were also related and validated with theoretical fracture toughness results having similar specimens size, concrete strength, and loading condition. The investigated parameters included the fiber volume fraction, concrete compressive strength, and notch length. The results showed that effective fiber content aligned horizontally across the crack path had a significant impact on fracture toughness and residual strength, and relatively noticeable impact on fracture parameters. In addition, the compressive strength and initial crack length had significant impact on the fracture parameters. This study followed innovative approach for assessing the impact of fibers aligned perpendicular to the direction of the crack propagation on the fracture parameters of concrete; the fibers were drawn individually in the simulation that was uniquely validated based on experimental and analytical results.

Keywords

• Fracture toughness
• Fracture energy
• NLEFM
• Synthetic fibers
• Four-point bending test