An integrated numerical–experimental approach for assessing mechanical and fracture behaviour in porous concrete

Porous concrete (PC) is increasingly used in pervious pavement systems due to its high permeability and environmental benefits, although its mechanical and fracture performance remains relatively limited. This study proposes an integrated experimental–numerical approach to investigate the mechanical and fracture behaviour of PC. An enhanced Lattice Discrete Element (LDE) numerical model is developed to realistically simulate unloading–reloading behaviour and the associated residual deformations in PC. The model parameters are derived from an experimental campaign including compression, elastic modulus, flexural and indirect tensile tests. Calibration is performed using four-point bending tests - with loading applied orthogonally to the compaction direction - while validation is carried out through three-point bending and indirect tensile tests. The numerical framework is then extended to account for compaction-induced anisotropy and applied to simulate fracture toughness and flexural behaviour under loading along the compaction direction. The results show good agreement between numerical predictions and experimental observations, demonstrating the capability of the proposed approach to reliably reproduce the mechanical and fracture response of PC. The novelty of this work lies in the development of an enhanced LDEM-based formulation capable of simulating unloading–reloading behaviour and residual deformations in PC, combined with a systematic experimental assessment that reveals compaction-induced anisotropy by investigating the material response under loading applied both along and orthogonal to the compaction direction, an aspect rarely addressed in the literature.