Threshold pore radius of concrete obtained with two novel methods

Author(s): Y. Sakai, C. Nakamura, T. Kishi
Paper category: Workshop
Book title: RILEM International workshop on performance-based specification and control of concrete durability
Editor(s): D. Bjegović, H. Beushausen, M. Serdar
ISBN: 978-2-35158-135-3
e-ISBN: 978-2-35158-136-0
Pages: 109 - 116
Total Pages: 8
Language: English

Abstract: 
This study proposes two methods for measurement of concrete threshold pore radius, defined as the minimum pore size through which a mass has to pass for penetration to be possible. The first method uses mercury intrusion porosimetry (MIP) analysis in which epoxy resin is applied on the sample to induce abrupt intrusion at the threshold pore radius. The obtained threshold pore radius shows good correlation with water/surface air permeability and confirms that abrupt intrusion occurs at the threshold pore radius. These results indicate that both water permeability and surface air permeability are governed by threshold pore radius. However, this method is time consuming. The second method is developed on the basis of the empirical critical volume fraction for percolation, which assumes that when 16% of the cement paste was filled with mercury in MIP analysis, the corresponding pore radius is the threshold pore radius. The threshold pore radius obtained by this method agrees well with that obtained with the epoxy-coating method, which further supports the reliability of the threshold pore radius obtained by using the first method.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00