Pore structure features of pervious concretes proportioned for desired porosities and their performance prediction

The pore structure features such as the pore volume fractions, pore sizes, specific surface areas, and connectivity dictate the properties of any porous material. In this paper, an analysis of the pore structure features of pervious concretes designed for similar porosities using two different proportioning methods - one with higher paste contents and lower compactive efforts and another with lower paste contents and higher compactive efforts - is carried out. The porosities (both from volumetric and image analysis based methods) and characteristic pore sizes obtained from morphological functions are found to be statistically similar for the high-paste and low-paste content mixtures, while the low-paste content mixtures show a higher specific surface area of pores. The extracted pore structure features, when used in the Katz-Thompson equation for permeability prediction, result in over-estimation of permeability for specimens with larger pore sizes. A correction factor for the Katz-Thompson constant is found to be linearly related to the granulometry-based pore sizes. (C) 2011 Elsevier Ltd. All rights reserved.