Numerical modeling of the material behavior of micromechanically designed strain-hardening high performance fiber reinforced cementitious composites

Enhanced tensile properties of fiber reinforced concrete make it suitable for strengthening of reinforced concrete elements due to their superior corrosion resistance and high tensile strength properties. Recently, the use of fibers as strengthening material has increased motivating the development of numerical tools for the design of this type of intervention technique. This thesis presents numerical analysis results carried out on a set of concrete beams reinforced with short fibers. To this purpose, a database of experimental results was collected from an available literature. A reliable and simple three-dimensional Finite Element (FE) model was defined. The linear and nonlinear behavior of all materials was adequately modeled by employing appropriate constitutive laws and failure criteria in the numerical simulations. To simulate the fiber reinforced concrete cracking tensile behavior an approach grounded on the solid basis of micromechanics was used. The results reveal that the developed numerical models in this thesis can accurately capture the performance and predict the load-carrying capacity of such reinforced concrete members. Furthermore, a parametric study is conducted to investigate the effect of ECC aggregate content, ECC compressive strength, maximum aggregate size, admixture type and amount, water-cement ratio, fibre modulus of elasticity, fibre reinforced concrete-plain concrete compressive strength ratio, and fibre reinforced concrete layer thickness on the performance of fiber reinforced cementitious concrete beams.