1. Research Scientist, Zhejiang Institute of Transportation, Hangzhou, Zhenjiang 311112, China; formerly, Research Associate, Glenn Dept. of Civil Engineering, Clemson Univ., Clemson, SC 29634.
2. Associate Professor, Glenn Dept. of Civil Engineering, Dept. of Materials Science and Engineering, Clemson Univ., Clemson, SC 29634 (corresponding author).