Velocity gradients of concrete mass reconstructed based on measured fibre orientations in hardened concrete

Abstract

During the casting of steel bre reinforced concrete (SFRC) the orientation of bres is inuenced by ow dynamics of concrete mass. A simple theoretical model presented allows the calculation of velocity gradient matrices for concrete mass based on steel bre orientations measured in the hardened concrete samples taken from the dierent regions in the slabs. This made it possible to examine the realistic trends of the ow near the formwork or free surface or in the bulk material. Eigenvalues and eigenvectors of the matrices show the directions of the maximal and minimal velocity changes, which can be compared in dierent positions of the slabs. The outcomes of the study can contribute to controlled production technology of SFRC.

Impact Response of Hammerhead Pier Fibrous Concrete Beams Designed with Topology Optimization

“…As tensile stresses increase, either the bond between fibers and concrete breaks gradually until bond pull-out failure or the fiber ruptures when tensile stress exceeds its tensile strength [57]. The orientation of fibers and dispersal are two factors that can have a profound effect on the impact resistance of fibrous hammerhead concrete beams, consequently influenced by mixing method, casting technique, and beam/ specimen dimensions [58][59][60][61][62]. The impact energy results are shown in Fig.…”