The Asphalt Team at TFHRC is currently working on the development of 3-dimensional imaging techniques to analyze the different components of asphalt concrete.
Our goal is to develop a better understanding of asphalt concrete, and to apply this knowledge to generate better performance in our pavements.
Through a multidisciplinary approach, our objectives are:
Why?
The methods that are currently being used for the description of aggregate structures are based on consensus properties. In fact, most of the information available on gradation, angularity, texture, and volumetric properties of asphalt pavement is solely based on previous field experiences. By developing imaging techniques that can help us visualize the effect of aggregate distribution on the strength of asphalt pavement, we will be able to quantify the properties that directly affect pavement performance and thus to design more durable pavements.
How?
Our basic approach is to develop parameters that describe the aggregate structure. By relating those parameters to performance, we will be able develop a deeper understanding of the structure, optimize the parameters, and thus optimize pavement performance.
One way to do so is by treating asphalt concrete as granular material (versus homogenous isotrophic material), and to use granular mechanics as a means to describe the stress-strain behavior of pavements. Photoelastic imaging and mechanics modeling are being used to obtain qualitative and quantitative descriptions of aggregate structures. Unlike previous efforts, our techniques will incorporate the effect of asphalt/mastic on pavement performance.
Future applications?
One will be able to perform:
U.S. Department of Transportation
Federal Highway Administration
Research and Development
Turner-Fairbank Highway Research Center
6300 Georgetown Pike
McLean, Virginia 22101-2296