2011 Volume 67 Issue 3 Pages 351-360
High-resolution-type X-ray CT is used to investigate the pore structure of air entrained mortars (AE mortar). Pore size distribution, pore spacing factors and air contents are calculated based on the results of three dimensional image analysis. The number of fine pores with 40 to 50μm in diameter is the largest with the largest pore size extending to 300μm. Pore spacing factors of AE mortar range from 113 to 137μm while they are 290 to 495μm for Non-AE mortars. Conventional method using a microscope apparatus shows less pores with the size equal to or larger than 100μm. Freezing and thawing resistance of fly ash mortar can be improved by the presence of air entrained voids.