By Mark Blow, P.E.

Over 50 years ago, the Asphalt Institute introduced full-depth asphalt. These full-depth pavement structures were thick (often 10-20 inches on high volume roadways) and were built directly on the subgrade as opposed to modern layered pavement design that typically includes granular base.

Pavement distresses such as fatigue cracking and potholes were nearly non-existent on these deep strength pavements. However, it quickly became apparent that thermal cracking was an issue, especially on non-granular soils in extreme climates.

We talk with leading educators and researchers to learn more about the people and topics of asphalt technology.

Dr. Stephen A. Cross, Ph.D., P.E. is a recently retired professor from Oklahoma State University’s Department of Civil and Environmental Engineering.

What drew you to transportation engineering?