Modeling Complex Material Interactions to Replicate and Uncover Mechanisms Driving the Performance of Steel Fiber-Reinforced Concrete Cylinders

This research focuses on the design and performance of Steel Fiber-Reinforced High-Strength Concrete (SFRHSC) to identify the optimal fiber content. The critical challenges involve the fiber content optimization and the effect of fiber distribution on the SFRHSC’s mechanical properties. This study uses the fiber weight ratio as it is more precise for quantifying fiber content than the traditional volume one. The available data obtained from experimental investigations of fifteen cylindrical specimens with systematically varied fiber ratios ranging from 0 to 60 kg/m³ were used. Following the experimental data, a 30 kg/m³ fiber content optimizes the mechanical properties of concrete with a compressive strength of 85–90 MPa, showing a superior Poisson ratio, energy dissipation, and structural ductility. To further recognize and replicate these findings, the behavior of SFRHSC cylinders was simulated using the Lattice Discrete Particle Model (LDPM). In the first stage, the parameters were calibrated by curve-fitting the experimental results with simulations of cube specimens for a uniaxial compression test. Then, the model was validated by simulating a loading–unloading cycle to fit the results. Subsequently, the effect of cracking for each fiber content and verbal compressive strength on the energy dissipation was examined for different SFRHSC strength values. These findings provide valuable insights for developing and optimizing SFRHSC for advanced structural applications.