Progressive development of cracks in biochar–cement composites through multiscale analysis

作者：Muduo Li, Jingyi Liang, Xiaohong Zhu, Nemkumar Banthia, Hailong Ye, Daniel C.W. Tsang · 发表于：Computer-Aided Civil and Infrastructure Engineering · 年份：2025 · DOI：10.1111/mice.70090 · 被引用次数：9 · 研究领域：Concrete and Cement Materials Research、Innovative concrete reinforcement materials、Microbial Applications in Construction Materials

The intrinsic brittleness of the cement matrix limits its synergy with steel reinforcement bars, constraining energy dissipation and crack control capacity of concrete. Enhancing the ductility of cementitious materials is, therefore, essential for improving structural resilience. A porous carbon material, for example, biochar, offers a sustainable alternative that can improve ductility and energy dissipation capacity, while simultaneously contributing to carbon sequestration. Despite promising experimental observation, the fracture mechanisms underlying this toughening effect remain insufficiently understood. This study addresses this knowledge gap by developing a multi-scale voxel-based modeling framework for biochar–cement composites, linking microscale mechanical heterogeneity to macroscale fracture behavior. The elastic modulus of biochar–cement paste was first quantified across nanoscale (∼nm and ∼µm) to mesoscale (∼mm and ∼cm) through nano- and micro-indentation, providing scale-bridged inputs for the model. The framework explicitly resolves aggregates, interfacial transition zones, and biochar particles within a concurrent multi-scale domain, enabling simulation of localized fracture while retaining computational efficiency. The simulation results were validated through a three-point bending test and digital image correlation. These findings demonstrated that biochar could alter the crack propagation by redistributing interfacial stress and promoting multi-layered crac...