ABSTRACT
We propose a novel method for measuring the concrete threshold pore diameter, defined as the minimum pore diameter through which a mass has to pass for penetration to be possible. The method is based on the empirical critical volume fraction for percolation, which assumes that when https://www.w3.org/1998/Math/MathML"> 16 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429227196/8b5c0a5d-ddea-4c88-8eea-7152f7afb008/content/eq7843.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the cement paste is filled with mercury in mercury intrusion porosimetry, the corresponding pore diameter is the threshold pore diameter. The threshold pore diameter obtained with this method agrees well with that obtained with a method proposed by us in the past. Next, we imaged the spatial distribution of the pore network using FIB-SEM. In the observed region, pores smaller than https://www.w3.org/1998/Math/MathML"> 30 n m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429227196/8b5c0a5d-ddea-4c88-8eea-7152f7afb008/content/eq7844.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are not interconnected. The observed minimum pore diameter in continuous pore space agrees reasonably well with the observed threshold pore diameter in this study.
