Since 1999, WRI has worked with the Federal Highway Administration, state transportation departments and their contractors to construct comparative pavement validation sites in Wyoming, Nevada, Arizona, Kansas, and Minnesota. Each comparative pavement validation site is a section of highway that includes consecutive pavement sections constructed with asphalts of the same performance grade but from different crude oil sources. The sites are “comparative” in that they allow direct comparisons between asphalts of the same performance grade over time.
By establishing validation sites in different climates and with different service patterns, WRI can study how materials perform under a greater variety of conditions. Annual monitoring of the sites allows us to observe the progression of distress and compare the distress from each section with the others in the site.
WRI uses the results to validate and calibrate laboratory and performance-related tests and models. As the different sections at a site age, the variations in their performance can be correlated with their material properties, such as compatibility and rheology. In this way, knowledge gained in the laboratory about the chemical and physical properties of asphalts and aggregates is correlated with field performance. And tests and predictive models can be developed and refined to distinguish performance with greater accuracy.
WRI is continually seeking to develop partnerships with states interested in constructing field validation sites.