Pore Structure Characterization of Pervious Concrete Using X-Ray Microcomputed Tomography

Abstract

Pervious concrete (PC) is a class of porous materials that has found application in building materials, specifically in pavements, for its stormwater mitigation abilities. X-ray microcomputed tomography was used to understand and quantify the three-dimensional (3D) pore morphology, shape factors, and size descriptors in PC mixtures prepared with varying porosity. The Zingg pore shape classification indicated higher percent of rod-shaped pores and the frequency of spheroid-form pores was higher in single-sized mixtures, whereas dense mixtures had higher occurrence of blade-form pores. The average pore sphericity was in the range of .4–.6, indicating semispherical pores. Few large-sized pores in PC had a significant influence on the relation between 3D pore-structural-permeability properties. The visualization of 3D pore structure indicated the importance of isolated pores in PC for periodic maintenance. The new findings on the pore structure will assist in mix design optimization, selection of mixtures, and modeling of PC.