The influence of fiber orientation on bleeding of steel fiber reinforced cementitious composites

The bleeding of steel fiber reinforced cementitious composites influences the durability and mechanical properties of hardened composites, fiber orientation affects the bleeding of the composites. This paper focuses on the influence of fiber orientation on the bleeding of cementitious composites. A simplified mathematical model based on fluid mechanics is proposed to investigate the influence of fiber orientation on bleeding, and a series of experiments are carried out to assess the difference in bleeding between aligned and non-aligned (randomly oriented) fibers in steel fiber reinforced cementitious composites. The research results indicate that the bleeding characteristics of the composites are greatly affected by the inclination angle of fibers in the matrix. The bleeding content increases as the inclination angle of fibers increases, and the bleeding content of horizontally aligned steel fiber reinforced cementitious composites (ASFRCC) is much less compared to non-aligned (randomly oriented) steel fiber reinforced cementitious composites, vertical fiber ASFRCC, and plain concrete.