The National Academies

SHRP 2 R06(C) [Completed]

Using Both Infrared and High-Speed Ground Penetrating Radar for Uniformity Measurements on New HMA Layers

  Project Data
Funds: $522,500
Research Agency: Texas A&M
Principal Investigator: Tom Scullion
Effective Date: 3/6/2009
Completion Date: 12/31/2013

Project snapshot. More details below.

(Project Number)
Impact on Practice
Product Status

Two nondestructive techniques for detecting defect areas in asphalt pavements during construction. PAVE-IR measures the real-time mat temperature. Ground-penetrating radar measures pavement density after rolling. Recommendations for equipment and testing protocols were also developed. A training video explaining how to use the technologies and interpret the data has been produced.
These technologies overcome some drawbacks of standard testing methods to advance practice and provide new efficiencies in pavement construction. Costly and time-sensitive nuclear testing becomes unnecessary. Both technologies (infrared and radar) test essentially 100 percent of the pavement area, providing much more inspection coverage than existing quality control methods. Detecting defect areas during construction allows the paving crew to adjust in real time, which avoids costly corrections and more reliably produces long-lasting pavements.
These technologies were pilot tested in Vermont in conjunction with FHWA’s Every Day Counts program.

The final report, training materials, video, and specifications for testing procedures are available at www.trb.org/Main/Blurbs/167280.aspx.

The Project Brief is available at https://www.trb.org/Main/Blurbs/170538.aspx
Staff Responsibility: Matt Miller

In-place density is a critical factor in determining pavement durability in hot-mix asphalt (HMA). Localized nonuniform zones of mix, termed segregation, often become low-density areas in the mat. Segregation continues to be a major construction-related problem with a significant adverse impact on pavement service life. Real-time nondestructive testing (NDT) procedures are ideal tools for providing feedback to paving crews, and recent studies have shown that infrared (IR) imaging and ground-penetrating radar (GPR) can be used to assess in-place density during construction while providing nearly 100 percent testing coverage of the constructed area.

The objective of this project was to demonstrate IR and GPR technologies as NDT techniques to assess HMA density and segregation and to make recommendations for how these technologies can be incorporated into existing department of transportation specifications for construction quality assurance.

This project summarized the availability of infrared and radar systems suitable for testing essentially the entire surface area during new HMA construction, and then it demonstrated an IR sensor bar system and two GPR systems on construction projects in each of the four American Association of State Highway and Transportation Officials (AASHTO) regions. The thermal profiling system demonstrated provided a real-time view of thermal uniformity and correlated well with the constructed mat density. The IR system is now commercially available, and the final report presents options for how agencies could implement the technology. Demonstration of the GPR systems showed they are suitable for evaluating pavement uniformity and can detect low-density defect areas in new overlays. However, streamlining of the data collection and processing needs to take place before GPR can be widely implemented and incorporated into specifications. The final report presents a framework for accomplishing the automation of the GPR process to achieve an implementable system.

The results of Renewal Project R06C were incorporated into an electronic resource for practitioners, known as the NDToolbox, which provides information regarding recommended technologies for the detection of a particular deterioration. The NDToolbox is available at https://www.ndtoolbox.org/ and was created by SHRP 2 Renewal Project R06A: Nondestructive Testing to Identify Concrete Bridge Deck Deterioration

Renewal Project R06C is one of seven follow-on projects to SHRP Renewal Project R06: A Plan for Developing High-Speed, Nondestructive Testing Procedures for Both Design Evaluation and Construction Inspection.

Project Status: This project is complete.

Product Availability: Using Both Infrared and High-Speed Ground Penetrating Radar for Uniformity Measurements on New HMA Layers, SHRP 2 Report S2-R06C-RR-1, was published in May, 2013.  It is available as an Adobe PDF.  A printed version is available through the TRB bookstore.  An e-book version of this report is available for purchase at Google, iTunes, and Amazon.  A fact sheet and project brief are also available.


This page was last modified on December 31, 2013.

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