Porosity and Permeability in Construction Materials as Key Parameters for Their Durability and Performance: A Review

This review provides a comprehensive examination of porosity and permeability as key parameters governing the durability and performance of construction materials, including natural stone, mortar, concrete, and other cementitious composites. It highlights the pivotal role of pore structure in transport phenomena and degradation mechanisms, examining how the variations in pore architecture, encompassing total vs. effective porosity, pore size distribution, and pore connectivity, dictate a material’s response to environmental stressors. A comparative evaluation of advanced pore characterization techniques is presented, including helium pycnometry, mercury intrusion porosimetry (MIP), nitrogen adsorption (BET/BJH), nuclear magnetic resonance (NMR) relaxometry, and imaging methods such as optical microscopy, scanning electron microscopy (SEM), and X-ray micro-computed tomography (micro-CT). Furthermore, it assesses how these porosity and permeability characteristics influence durability-related processes like freeze–thaw cycling, chloride ingress, sulphate attack, and carbonation. Case studies are discussed in which various additives have been employed to refine the pore structure of cement-based materials, and pervious concrete is highlighted as an example where deliberately high porosity and permeability confer functional benefits (e.g., enhanced drainage). Overall, these insights underscore the importance of tailoring porosity and permeability in material design to enhance durability and sustainability in construction engineering.