This research aims to shed light on the effect of steel fiber shape, length, diameter, and aspect ratio on the mechanical properties of slurry infiltration fiber reinforced concrete (SIFCON). This study comprised of casting and testing three groups of SIFCON specimens with 6% fiber volume fraction. The first group was reinforced with micro steel fiber, other reinforced by hook end steel fibers, while the last group of specimens reinforced by mixing two shape of steel fiber as hybrid fiber (3% micro steel fiber +3% hook end steel fiber). Silica fume was used as a partial replacement (10%) by weight of cement. 3.7% super plasticizer was used to make the slurry liquid enough to penetrate through the fiber network, while the w/c ratio kept constant at 0.33. It was found from the results achieved that the compressive strength, static modulus of elasticity, splitting tensile strength and toughness are extremely affected by the geometry of fibers because the network of fibers formed and their density depends on the size and shape of fibers. Where the values of micro steel fibers are far outweighing the values of hooked end fibers. It was also deduced from empiricism results that combining long and short fibers gives excellent results.

This paper looks at the effect of hollow ratio and cross-section shape on the behavior of hollow slurry infiltrated fiber concrete (SIFCON) columns and normal strength concrete (NSC) columns. The present study comprised casting and testing of two column specimens groups; SIFCON group and NSC group (reference group). Every group consists of six column specimens of which three are circular and the others are square. Each circular column has an identical square column with the same cross-section area. These six columns have different hollow ratios (β = 0, 25% and 50%) for SIFCON columns and (β = 0, 25% and 33%) for NSC columns. The fiber used in this study was straight micro steel fiber with a 6% fiber volume fraction. The test results proved that the SIFCON columns have an outstanding performance compared to the NSC columns in terms of load-carrying capacity, ductility, and energy absorption capacity. On the other hand, SIFCON columns have less stiffness than NSC columns. When the hollow ratio increases, the load-carrying capacity, ductility, and stiffness were reduced. The results also demonstrated that the performance of circular columns exceeded that of square columns for the same cross-sectional area.

This paper looks at the effect of fibers shape, hollow ratio and cross sectional shape on the behavior of solid and hollow slurry infiltrated fiber concrete (SIFCON) columns. Two shape of steel fiber were used in the present study, straight micro fiber and hooked end fiber. Therefore, this study comprised of casting and testing two groups of SIFCON column specimens; columns group reinforced by hybrid fibers (3% straight micro fiber + 3% hooked end fiber) and columns group reinforced by 6% hooked end fibers. Each group comprises of six column specimens, 3 of them are circular and the others are square. Each circular column has an equivalent square column with the same cross-sectional area. These six columns have different hollow ratios (β = 0, 25% and 50%). Non-linear finite element analysis of axially loaded SIFCON columns has been done by using ABAQUS computer program. Analytical predictions of load carrying capacity, axial displacement, ductility and energy absorption capacity are compared with experimentally observed results of SIFCON columns, and the results shown a good agreement between them. The results illustrated that despite the small cross-sectional area and presence of longitudinal hole in columns, SIFCON columns were shown dazzling performance in terms of load carrying capacity, ductility and energy absorption capacity especially for columns reinforced by hybrid fiber. On the other hand, column performance deteriorates with increased hollow ratio. The results also demonstrated that the performance of circular columns exceeded that of square columns for the same cross-sectional area.