1. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Auburn Univ., 238 Harbert Engineering Center, Auburn, AL 36849 (corresponding author).
2. Professor and Director of the Highway Research Center, Dept. of Civil and Environmental Engineering, Auburn Univ., 238 Harbert Engineering Center, Auburn, AL 36849.
3. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Auburn Univ., 238 Harbert Engineering Center, Auburn, AL 36849.