Simplified and Cost-Effective Method of Studying the Effect of Steel Fibers on Ultra-high Performance Concrete Specimens' Properties/Members' Performance

This research work, which presents a simplified technique of modelling steel fibers, uses python algorithm that can be directly run in ABAQUS to automatically generate the location and orientation of steel fibers in a rectangular ultra-high performance concrete specimen, so that the effect of steel fibers on the properties of such a specimen can be directly investigated through numerical simulation. This method is fast, can be applied to structural members of bigger dimensions (like beams, columns, slabs) unlike the existing methods that are only applicable to small size specimens, and also solves the problem associated with previous methods where some fibers may be generated and placed outside the boundary of a specimen, leading to the discard and regeneration of those fibers. To assess the validity of this method, experiments were conducted on the compressive properties of three ultra-high performance concrete cube specimens and the shear performance of two ultra-high performance concrete beams, and the results were compared with the ones obtained using this method. Results indicate over 97% agreement between the experiment and the numerical simulation in ultimate compression force and shear resistance at shear crack and ultimate load phases. The comparison also reveals perfect agreement in the failure mode and crack pattern of the specimens.