Meso-scale analysis of FRC using a two-step homogenization approach

This paper describes the development of a two-step homogenization approach for evaluating the elastic properties of fiber reinforced concrete (FRC). For that purpose, a finite element model of an FRC unit cell was generated. Prior to the generation of the unit cell finite element model, the interface transition zones (ITZ) and the aggregates were homogenized using an analytical approach. In the first step, the properties of a spherical aggregate and its concentric ITZ layer were homogenized via an analytical procedure. Then a numerical homogenization procedure was applied to the homogenized aggregate, the mortar, and the fibers to obtain the macroscopic properties of the FRC. The suggested framework executes the multi-scale analysis of FRC structures by incorporating an original concrete unit cell generator into a commercial finite element software package intended for simulating nonlinear solid mechanical problems. The results, obtained using the presented algorithm, are in very good agreement with experimental results.