Mesoscale Modeling of Dynamic Compressive Behavior and Damage Evolution in Rubberized Recycled Aggregate Concrete

Rubberized recycled aggregate concrete (RRAC) offers a sustainable solution for recycling construction and tire waste and shows potential for impact-resistant infrastructure. However, its heterogeneous mesoscale structure complicates the understanding of dynamic damage mechanisms. This study develops a mesoscale numerical framework to reproduce the dynamic compressive response and elucidate damage evolution in RRAC. A pseudo-3D seven-phase finite element model was established based on SEM/EDS observations, with the K&C model for cementitious phases and the Mooney–Rivlin model for rubber. The model was validated against SHPB tests and used to examine the effects of rubber content, strain rate, and aggregate shape. At approximately 70–80 s−1, dynamic compressive strength decreased from 55.1 MPa for RR0 (no rubber) to 29.3 MPa for RR40 (40% rubber), a 47% reduction. For RR20 (20% rubber), strength increased by 56%, from 38.5 MPa at 73 s−1 to 60.1 MPa at 201 s−1. At approximately 127 s−1, the toughness index increased from 1.803 for RR0 to 4.128 for RR30. Damage preferentially initiated at the rubber–matrix interfacial transition zone (ITZ) and propagated into adjacent regions. The framework clarifies the strength–deformability trade-off in RRAC and provides a computational basis for further assessment of its potential in impact-resistant infrastructure.