1. Associate Transportation Researcher, Materials and Pavements Division, Texas A&M Transportation Institute, 3135 TAMU, College Station, TX 77843-3135.
2. Transportation Engineer, Houston District Laboratory, Texas Dept. of Transportation, Houston, TX 77007.
3. Professor, Dept. of Civil Engineering, 362N Whittier Research Center, Univ. of Nebraska, Lincoln, NE 68583-0856 (corresponding author).
4. Graduate Research Assistant, Dept. of Civil Engineering, Univ. of Nebraska, Lincoln, NE 68583.
5. Assistant Materials and Research Engineer, Nebraska Dept. of Transportation, 1500 Hwy. 2, Lincoln, NE 68502.