Effects of fibers geometry and strength on the mechanical behavior and permeability properties of slurry infiltrated fiber concrete (SIFCON)

The use of slurry-infiltrated fiber concrete (SIFCON) has been increasing in recent years. SIFCON is a very good alternative, especially in structural reinforcement processes. In this study, the effects of 2 different steel fibers of normal strength (3D) and high strength (5D) with different geometry and strength properties and polyolefin origin synthetic fiber are examined on the mechanical behavior and capillary water permeability properties of SIFCON. Steel fibers were used in 2 different ratios by volume 4% and 8%, while polyolefin synthetic fiber was used at 4% by volume. The bending strength and splitting tensile strength of SIFCON containing 5D steel fiber are 46.47 MPa and 18.47 MPa, respectively, 4.9 and 2.1 times higher than plain concrete. In addition, the fracture energy of SIFCON containing 5D steel fiber is 20400 N/m, and it is 358 times higher than plain concrete, 1.6 and 3.1 times higher than concrete containing the same amount of 3D fiber and polyolefin synthetic fiber, respectively. The capillary water absorption of SIFCON, which contains 4% synthetic fiber and 8% 3D steel fiber by volume, is 0.121 mm and 0.112 mm, respectively, which is higher than all other mixtures in the study. As a result of the study, higher splitting tensile strength, bending strength and fracture energy values were obtained in concretes containing 5D steel fiber, which have high tensile strength and have better adhesion to concrete due to its geometry. The use of synthetic fibers or high amounts of steel fibers increased the permeability. 