Development and Implementation of the Asphalt Embrittlement Analyzer

This project will develop, demonstrate, and implement an acoustic emission-based system for rapid and reliable characterization of asphalt binder embrittlement temperatures. Work in Stage 1 will focus on extending the acoustic emission (AE) technique to extract discrete and continuous properties (embrittlement temperature) from age-graded material such as field cores. First, dispersion characteristics of longitudinal and shear waves will be studied using simple pencil breaks to simulate AE signals. Next, AE tests will be conducted on asphalt concrete field cores, where the embrittlement temperature (TEMB) of different layers of the pavement will be determined to obtain a discrete characterization of aging and existing condition (and remaining life) through the pavement thickness. AE tests will be conducted on field cores using two or more AE sensors mounted on the test core sample. By comparing the arrival times of AE events at different sensors, the location of the AE source will be estimated. With decreasing temperatures, microcracks are expected to first occur where more highly aged material is located (such as at the surface of the pavement core) followed by microcracks in less aged material (such as towards the pavement bottom). Field cores obtained from project collaborators (Asphalt Institute and Road Science) along with test pavements at the university's Advanced Transportation Research and Engineering Laboratory (ATREL) facility will be tested. Comparisons with results obtained from extraction, recovery, and binder testing will be made to validate results. This stage will also involve a collaboration with Troxler, where a cooling chamber will be retrofitted to allow closed-loop, linear cooling. Work in Stage 2 will begin with the development of a computer program for source location with capability to locate AE sources within an 1/8 inch resolution or better. Theoretical and experimental studies will be conducted to determine the best core geometry and sensor placement. A computer software will be developed to convert AE signals into an embrittlement profile and rehabilitation recommendations (guided by an expert system). Next, asphalt concrete cores obtained from the field that exhibit visible signs of distress will be tested. Working in collaboration with Troxler, Road Science and Asphalt Institute, a temperature-controlled device coupled with multi-channel AE and software will be completed to calculate TEMB and TMAX vs. depth and a prototype AE analyzer device suitable for commercialization will be developed. A series of maintenance strategies, and an expert system to guide designers towards an optimally designed rehabilitation strategy will be developed. The final report will provide all relevant data and guidelines and specifications for using the new test equipment and method along with plans for its implementation by highway agencies and commercialization by the collaborating industrial partners.


  • English


  • Status: Active
  • Contract Numbers:

    Project 20-30, IDEA

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway & Transportation Officials

    444 North Capitol Street, NW, Suite 225
    Washington, DC  United States  20001

    National Cooperative Highway Research Program (NCHRP) Innovations Deserving Exploratory Analysis (IDEA)

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Jawed, Inam

  • Performing Organizations:

    University of Illinois, Urbana-Champaign

    1406 W. Green Street
    Urbana, IL  United States  61801
  • Principal Investigators:

    Buttlar, William

  • Start Date: 20141209
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 38200

Subject/Index Terms

Filing Info

  • Accession Number: 01547491
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-30, IDEA
  • Files: TRB, RiP
  • Created Date: Dec 10 2014 1:02AM