Correlation between Permeability of Concrete and Threshold Pore Size obtained with Epoxy-Coated Sample

Abstract

The authors have proposed a new method, epoxy-coating on MIP (Mercury Intrusion Porosimetry) sample, to measure threshold pore radius of concrete to obtain an indicator of pore structure which has correlation with air and water permeability. In this paper, first, the validity of the above method was studied through observation on splitting surface of samples after MIP analysis and comparison with obtained threshold pore radius and permeability. Results showed that the proposed method is suitable to extract threshold pore radius, and it showed good correlation with water permeability and, if concrete is enough dried, air permeability. Good correlation was found even on samples prepared with overseas concrete material and core samples taken from existing structures overseas. The above results indicate that pore structure governs both air and water permeability of concrete and that threshold pore radius can be an indicator of the permeability of concrete.