Remote Sensing to Improve Maintenance Timing-ASAP

June 16, 2008

Under the new two-year Cooperative Agreement with the U.S. Department of Transportation’s Research and Innovative Technology Administration (RITA), WRI is partnering with Innova Engineering, LLC, of Navarre, Florida, to develop an Asphalt Surface Aging Prediction (ASAP) remote-sensing system. This first-of-a-kind infrared sensing system will collect spectrographic samples in the field that can be used to predict asphalt aging in a manner similar to proven laboratory test techniques. 

Asphalt pavement surface treatments seal cracks and can make pavement surfaces more flexible and resistant to further cracking. One of the problems in asphalt pavement maintenance, however, is determining when to apply surface treatment. The goal of a new WRI remote sensing effort is to make it possible to time application before significant surface cracking develops, yet avoid excessive treatments―exactly what is needed to prolong highway life. 

Increased pavement surface stiffness is caused by oxidative aging of the asphalt component of the pavement. Laboratory aging tests and measurements on pavement samples have shown distinct relationships between asphalt aging as indicated by chemical oxidation products and the asphalt stiffness, or modulus, measured by physical methods. These results are the basis for developing the rapid, non-contact sensing technique in which specific spectral signatures associated with chemical functional groups may be measured to indirectly measure the stiffness of the asphalt at the pavement surface. 

Innova Engineering will develop a Fourier Transform Infrared (FTIR) Michelson interferometer spectrometer using new monolithic optical block technologies pioneered by PLX, Inc. of Deer Park, New York.  The result will be a “ruggedized” FTIR. 

WRI will conduct a series of asphalt aging tests using laboratory FTIR spectrometers to improve detection of carbonyl content in asphalt pavement and its relationship to asphalt stiffness and aging prediction. With measurements at different aging times or with a laboratory calibration on the same asphalt, appropriate treatment times may be predicted. 

The research team will work with state and local agencies, industry partners and service providers to field test the ASAP system for determining the structural integrity and life span of asphalt pavement in order to reduce maintenance costs.