ISSN: 1945-7553
CODEN: JTEVAB
Published Online: 26 November 2012
Page Count: 7

Characterization of Asphalt Mixture Homogeneity Based on X-ray Computed Tomography

Hu, Chichun
Lecturer, College of Civil and Transportation Engineering, South China Univ. of Technology, Guangzhou,

Youtcheff, Jack
Team Leader, FHWA Turner-Fairbank Highway Research Center, Mclean, VA

Wang, Duanyi
Professor, College of Civil and Transportation Engineering, South China Univ. of Technology, Guangzhou,

Zhang, Xiaoning
Professor, College of Civil and Transportation Engineering, South China Univ. of Technology, Guangzhou,

Kutay, Emin
Assistant Professor, Dept. of Civil and Environment Engineering, Michigan State Univ., East Lansing, MI

Thyagarajan, Senthilmurugan
Highway Research Engineer, FHWA Turner-Fairbank Highway Research Center, Mclean, VA

(Received 12 May 2012; accepted 10 September 2012)

Abstract

The mechanical performance and life span of asphalt pavement depend largely on the homogeneity of the asphalt mixture. Inhomogeneity of asphalt mixtures is due to the non-uniform segregation of air voids and aggregates in mixtures. In order to evaluate the homogeneity of an asphalt mixture during lab compaction, computed tomography (CT) images of the specimen were obtained based on x-ray CT. The image was virtually cut into slices of various sizes, and the vertical air void distributions and aggregate gradations were quantified. Research results reveal that the air void content in the middle part of the specimen was lower than those on both ends. Also, the homogeneity was better under high compaction levels. The results from aggregate gradations were in good agreement with air void distribution calculations. Therefore, it is feasible to characterize an asphalt mixture’s homogeneity based on the air void distributions and aggregate gradations as determined via x-ray CT.

Keywords:
asphalt mixture, x-ray computed tomography, air void, aggregate gradation, homogeneity evaluation

Paper ID: JTE20120159
DOI: 10.1520/JTE20120159
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