Revisiting the Katz-Thompson Relationship Between Permeability, Electrical Resistivity, and Formation Factor for Cementitious Systems
Year: 2026
Type: preprint
Abstract: Fluid transport is important for determining the durability of concrete structures. Fluid transport modeling approaches in cement-based materials are powerful but require the intrinsic permeability (K l ), which is often challenging due to experimental limitations. Therefore, K l is typically estimated using its established relationship with various parameters representing porous structure, such as the Katz-Thomson formulation, which relates K l to formation factor (F) and the square of the critical pore diameter (d c ). However, obtaining d c , from either direct or indirect experimental methods, is rather challenging, and these measures often show a high degree of variability. This study re-evaluates the fundamental relationship between K l and the pore structure of cement-based materials without relying on conventional d c measurements. Experimental data show that intrinsic permeability is inversely proportional to the square of the formation factor (K l ∝ F -2 ), which is in line with earlier studies on non-cementitious porous media where K l was proportional to F -m without any dependence on d c . The specific proportionality holds across all tested mixtures in three separate studies although the relationship varies in each paper. This may be due to variations in the experimental procedures or the presence of aggregate and ITZ. This alternative formulation can be very powerful in enabling practical and accurate durability predictions for concrete infrastructure.
Source: ChemRxiv
Institution: Oregon State University
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7211889188