Short Fibers Distribution Investigation in Fiber Concrete

Steel fiber reinforced high-strength (SFRHSC) concrete post cracking load –bearing capacity (and strength) is dependent on the number of fibers crossing weakest crack (bridged by fibers) and their orientation to particular crack surface. Filling the mould by SFRHSC, fibers are moving and rotating moving with the concrete matrix till the end of motion in every concrete body internal point. Filling the same mould from the different ends SFRHSC samples with the different internal structures (and different strength) can be obtained. Numerical flow simulations (using Newton and Bingham flow models) were performed, as well as single fiber planar motion and rotation numerical and experimental investigation in viscous flow. X-ray pictures for prismatic samples were obtained and internal fiber positions and orientations were analyzed. Similarly fiber positions and orientations in cracked cross-section were recognized and were compared with numerically simulated. Structural SFRHSC fracture model was created based on single fiber pull-out laws, which were determined experimentally. Model predictions were validated by 15x15x60cm prisms 4 point bending test