Finite Element Analysis and Validation of Axial Capacity of RC Columns Made of Steel Fiber Reinforced Concrete (SFRC)

Abstract

Steel Fiber Reinforced Concrete (SFRC) possesses many excellent dynamic performances such as; high resistance to explosion and penetration. It has little effect on pre-cracking behavior in uniaxial compression, but substantially enhances its post cracking response. This response leads to a greatly improved ductility and toughness. Steel fibers in SFRC are capable of preventing crack propagation as well as brittle failure of columns under uniaxial compression. To this end, four reinforced concrete (RC) square columns and four circular columns made of plain concrete and SFRC are casted and tested in a 1000 kN capacity universal testing machine (UTM) to evaluate the axial capacity enhancement due to steel fibers. Enlarged-end fiber is used in this study which is prepared in the laboratory. Three different aspect ratios of steel fibers (i.e., 40, 60 and 80) are used to cast the specimens with steel fiber at 1.5% by the volume of concrete. The axial capacity is found to be increased 6, 12 and 21% for steel fiber aspect ratio 40, 60 and 80, respectively in case of square columns. The enhancements in circular columns are 27, 24 and 20% for steel fiber aspect ratio 40, 60 and 80, respectively. These columns are modeled in the finite element platform of ANSYS 11.0 and the FE outcomes and failure patterns uphold a good agreement with the experimental results. These results will help the construction industry of Bangladesh with reliable experimental data and validated FE modeling of this composite material.

Keywords: Concrete, uniaxial compression, columns, tensile strength