Constitutive Relations of Randomly Oriented Steel Fiber Reinforced Concrete under Multiaxial Compressive Loadings

摘要

A review of the state-of-the-art research on steel fiber reinforced concrete (SFRC) is given and a review of the behavior and strength of plain concrete subjected to multiaxial stresses is presented. Two series of tests on SFRC were conducted. The first preliminary series, provides results of some basic tests on concrete randomly mixed with each of five types of commercially available steel fibers. This information allowed the determination of the optimum fiber to use in the second, final test series, where the properties of SFRC under three-dimensional compressive loadings are investigated. The conclusions drawn from the test results are that the addition of steel fibers to plain concrete increases the toughness, ductility and stiffness of the material. The greatest improvement of the tensile strength is provided by the longer fibers, whereas the opposite is true regarding the compressive strength. The reproducibility of the experimental results is good and the SFRC proved to be nearly isotropic as observed from the multiaxial tests.