Modeling and mechanical influence of meso-scale concrete considering actual aggregate shapes

Aggregate shape modeling is critical to concrete failure in mesoscale numerical simulation, However, most studies replaced actual aggregate with basic geometry, which caused the imprecise results. Combined with laser scanning technique and spatial random cutting, an actual aggregate database containing 1568 2D particles was formed. To realize rapid placement of particles with complex boundary, an indirect overlapping detection method based on rectangular fitting of aggregate is proposed, and the corresponding modeling method is also established. Uniaxial compression simulations of 30 cubes with different particle size groups were carried out, and parameter statistics of aggregate shape (elongation ratio, circularity and roughness) in the models were calculated. The results show that the effect of large size aggregate on the crack and strength is more obvious, and the difference in elongation ratio and roundness distribution of aggregate cause the fluctuation of concrete strength. (C) 2019 Elsevier Ltd. All rights reserved.