ABSTRACT
This paper validates a computationally efficient 2.5D approach for modelling cohesive discrete cracks in concrete at the mesoscale. The proposed method relies on extracting a series of planar, two-dimensional slices from a full three-dimensional geometry and coupling them through horizontal and vertical springs that transfer force interactions between adjacent layers. The main objective of this approach is to effectively reconstruct the essential three-dimensional mechanical response while maintaining the computational efficiency of two-dimensional analyses. The validation is performed using two benchmark configurations: a dogbone-shaped tensile specimen and a notched three-point bending beam, both featuring stochastically generated mesostructures with ellipsoidal aggregates. Key model parameters are systematically examined, and mesh-sensitivity analyses ensure solution objectivity. The study conducts comprehensive performance comparisons between isolated 2D models, the proposed 2.5D layered approach, and full 3D simulations to evaluate crack-propagation patterns, force–displacement and computational efficiency. The results demonstrate that the 2.5D approach achieves an optimal balance between accuracy and computational cost, making it a practical alternative to full three-dimensional simulations for mesoscale concrete fracture analysis.
