Dynamic tensile response of fiber reinforced concrete

• Systematically elucidating the dynamic tensile behavior of fiber reinforced concrete through experimental and numerical approaches; • Establishing correlations between fractal characteristics of fracture surface roughness and macroscale mechanical properties; • Quantitatively investigating the toughening effect of fibers based on damage evolution. In order to investigate the effects of steel fibers, basalt fibers, and polypropylene fibers on the dynamic tensile behavior of concrete, dynamic Brazilian disc splitting tests and numerical simulations were conducted on different fiber reinforced concrete. The study explored the dynamic tensile performance of fiber reinforced concrete from both macroscopic and microscopic perspectives. The results show that, under the same impact velocity, polypropylene fiber reinforced concrete exhibits the highest splitting tensile strength. The splitting tensile strength of different fiber reinforced concrete is negatively correlated with the fractal dimension of broken fragments, while the surface roughness is positively correlated with the fractal dimension of broken fragments. Fibers dissipate energy through multiple mechanisms including bridging, interfacial friction, and elastoplastic deformation, significantly enhancing the toughness of concrete. The numerical simulation reproduces the damage evolution path of different fiber reinforced concrete under “left-side impact loading-damage propagation parallelly-right-side reflection tension-symmetrical fracture”. Acoustic emission analysis indicates that steel fibers and polypropylene fibers can delay damage progression, while basalt fibers primarily enhance dynamic tensile strength through bridging effects and interfacial friction.