1. Research Civil Engineer, U.S. Army Corps of Engineers, Engineer Research and Development Center, CEERD-GM-A, 3909 Halls Ferry Road, Vicksburg, MS 39180 US.
2. Associate Professor, Materials and Construction Industries Chair, Department of Civil and Environmental Engineering, Mississippi State Univ., 501 Hardy Road; PO Box 9546, Mississippi State, MS 39762, US, e-mail: ilhoward@cee.msstate.edu