Scholarlink

<p>Bridging-type CaCO<sub>3</sub> cementation formed during microbially induced calcium carbonate precipitation (MICP) provides direct load transfer between particles, yet its tensile behavior and failure mechanisms at the particle scale remain insufficiently understood. This study investigates dual-particle MICP specimens with different cementation radii through particle-scale tensile tests, microscopic observations, and discrete element modeling and analyzes their strength distribution, mechanical response, failure modes, and micromechanical controls. Under identical precipitation conditions, the peak tensile loads show pronounced scatter and follow a Weibull distribution. Increasing the cementation radius raises both the characteristic tensile strength and the Weibull modulus, thereby improving load capacity and mechanical stability. Although all specimens exhibit elastic loading, crack propagation, and unstable fracture, the statistical preference of failure modes is not governed directly by size. Instead, size alters the relative influence of local weak features such as internal deposition discontinuities or interfacial deficiencies, which shifts the most probable failure path. Microscopic observations confirm that through-bond fractures relate to internal discontinuities, interface failures reflect insufficient interfacial bonding, and mixed failures arise from the combined action of interior defects and interface weakening. DEM simulations further indicate that cementation size mainly affects peak force through changes in the effective load-transfer area, whereas the failure path depends on the relative tensile capacities of the interface and the interior. As a result, size influences failure mode indirectly by modifying how weak zones are spatially expressed. Analyses of crack evolution, energy release, and force-chain collapse all show behavior characteristic of tensile-dominated fracture. This work clarifies the respective roles of geometric scaling and interface–interior strength contrast in the statistical evolution of failure modes and offers guidance for interface design and parameterization in numerical models for MICP-treated granular materials.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Micromechanical insights into the tensile behavior of MICP bridge bonds: dual-particle experiments and DEM modeling

  • 期刊论文

  • 发表日期：

    2026年3月18日

查看全文
  • Baomin Liu,
  • Yunyi Long,
  • Linxian Gong,
  • Yi Jin,
  • Yan Xu,
  • Zhazha Hu,
  • Tingen Zhu,
  • Zhiyong Zhang

摘要

Bridging-type CaCO3 cementation formed during microbially induced calcium carbonate precipitation (MICP) provides direct load transfer between particles, yet its tensile behavior and failure mechanisms at the particle scale remain insufficiently understood. This study investigates dual-particle MICP specimens with different cementation radii through particle-scale tensile tests, microscopic observations, and discrete element modeling and analyzes their strength distribution, mechanical response, failure modes, and micromechanical controls. Under identical precipitation conditions, the peak tensile loads show pronounced scatter and follow a Weibull distribution. Increasing the cementation radius raises both the characteristic tensile strength and the Weibull modulus, thereby improving load capacity and mechanical stability. Although all specimens exhibit elastic loading, crack propagation, and unstable fracture, the statistical preference of failure modes is not governed directly by size. Instead, size alters the relative influence of local weak features such as internal deposition discontinuities or interfacial deficiencies, which shifts the most probable failure path. Microscopic observations confirm that through-bond fractures relate to internal discontinuities, interface failures reflect insufficient interfacial bonding, and mixed failures arise from the combined action of interior defects and interface weakening. DEM simulations further indicate that cementation size mainly affects peak force through changes in the effective load-transfer area, whereas the failure path depends on the relative tensile capacities of the interface and the interior. As a result, size influences failure mode indirectly by modifying how weak zones are spatially expressed. Analyses of crack evolution, energy release, and force-chain collapse all show behavior characteristic of tensile-dominated fracture. This work clarifies the respective roles of geometric scaling and interface–interior strength contrast in the statistical evolution of failure modes and offers guidance for interface design and parameterization in numerical models for MICP-treated granular materials.