ABSTRACT
Numerical investigations from a recent blind prediction of T beams with steel-fibers and conventional reinforcement are presented. The blind prediction was organized by the fib Working Group Modelling of Fiber Reinforced Concrete Structures in 2019, where two identical, simply supported T beams were loaded in three point bending up to failure. Both beams failed in shear, reaching an average maximum capacity of 336kN. The submitted prediction resulted in a failure load of 331kN and was ranked 1st among 34 predictions from research and industry. In this paper, first the numerical model used for the blind prediction is presented, which consisted of a two-dimensional FE model with smeared reinforcement calibrated using notched beam tests made available to the participants. Next, analyses addressing objectivity of results with mesh refinement and the choice of constitutive modelling parameters is presented. The influence on the load-displacement response, longitudinal strain underneath the point of load application and crack pattern is investigated.
