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2016 Leonard E. Wood Lecture

Is Hot Mix Asphalt a Rational Material?

by Dr. Thomas D. White
Professor of Civil Engineering
Mississippi State University

Thursday, October 27, 2016
3:30pm - HAMP 1144


In the early development of the asphalt paving industry, hot mix asphalt (HMA) was marketed by contractors as a proprietary product. Patents were sought and granted to protect the technology.  The mixtures of aggregate and asphalt were produced based on a recipe of the aggregate source, gradation and amount of asphalt. As HMA use spread, agencies required certain characteristics of the HMA and subsequently developed tests and adopted index values to aid in proportioning and evaluating HMA.  Several tests were developed in the 1930s and 1940s.  With a few exceptions such tests with specified index values continue with some modifications. In somewhat parallel, the aircraft industry transitioned from index testing and pulling, compressing, and bending aircraft frames until they broke to rational material testing and validation of the airframe structural analysis.  The question is, “Has the technology for testing and analysis of HMA pavements progressed along with that of the aircraft and other industries?”  The case is made for an approach to HMA testing, pavement analysis and validation that answers this question.

Thomas D. White, Professor of Civil Engineering at Mississippi State University, Starkville, MS.  He is also Professor Emeritus of Civil Engineering at Purdue University, West Lafayette, IN.  He joined the faculty in Civil Engineering at Purdue University in 1984. In 1999 he was named Professor and head of Civil Engineering at Mississippi State University and stepped down from that position in 2006. Other work experience includes design engineer with Varco Steel in Pine Bluff, AR; Regional Director for Chem-Crete Corp., Vicksburg, MS; Chief of the Pavement Materials Research Facility, and Chief of the Pavement Systems Division at the USAE Waterways Experiment Station, Vicksburg, MS; and Research Engineer with the Center for Transportation Research at the University of Texas in Austin, TX.