Coupling between progressive damage and

This study focuses on the significant increase of concrete permeability due to micro-cracking and the correlation between material damage and permeability defined by the material's stiffness. We utilize lattice analysis to investigate this relationship theoretically. The first part of the paper presents a scaling analysis of lattices with constant elastic brittle bonds, demonstrating that material degradation should be characterized by the evolution of material stiffness in a continuum damage framework. The second part addresses hydro-mechanical problems by constructing a hydraulic lattice that is dual to the mechanical lattice. Our findings reveal that the average permeability during micro-cracking serves as a scale-independent variable in hydraulic problems. Additionally, in a continuum perspective, the evolution of material permeability is linked to the elastic unloading stiffness, which can be expressed through continuum damage variables. The results provide a comprehensive understanding of the interplay between damage evolution and permeability in concrete structures.