A New Tool for Pavement Evaluation

Published May 22, 2017

Repairs and maintenance for the transportation infrastructure of Illinois present a potentially huge cost to the state. In order to test new technology that  could provide “effective, efficient, economical, and rapid data collection” of pavements and bridge decks for the purpose of evaluation of their condition and the need for repairs, IDOT teamed up with ICT in a recent project, Ultrasonic Imaging for Concrete Infrastructure Condition Assessment and Quality Assurance (R27-146).

Mira Device and laptop

The focus of this project was on evaluating a new piece of technology called MIRA, a portable ultrasonic shear wave tomography device that has the potential to allow field workers to asses these structures quickly and efficiently. A team of researchers, led by principal investigators John Popovics (UIUC), Jeffery Roesler (UIUC), and TRP chair Douglas Dirks (IDOT), recently completed their report evaluating MIRA’s effectiveness in a variety of field applications.

Mira B-scan showing pavement thickness and dowel bar locations

For the project, the researchers evaluated several tasks where MIRA might be able to improve on current methods. They then categorized these tasks in the report as either field ready, potentially ready, or challenging, to indicate which tasks MIRA was best suited for. They found that MIRA was field ready for internal and parapet voiding, duct positions, slab thickness, and initial condition survey of dowel bars/reinforcement; had potential for use in evaluating concrete delamination, concrete/asphalt bonding, bonding of overlays and fiber reinforced polymer (FRP) wrap, and precise rebar location and sizing; and that several tasks would be challenging to accomplish with MIRA, including distributed cracking/surface-breaking crack depth, duct grout condition, corrosion, and evaluating heavily reinforced structures.

Popovics notes that he “liked the opportunity to implement newly developed technology to meaningful practice in the field.” In support of this effort, they also produced a user’s manual (Appendix E of the report) to “assist in introducing new users to the proper operation and interpretation of the MIRA device” and presented their findings at an implementation training session held for engineers in the transportation sector on February 27, 2017, just before the annual Transportation and Highway Engineering Conference.

According to John Popovics, this project went smoothly thanks to a great working relationship with IDOT and the TRP. “The highlight was the end of project implementation training session that we held for transportation engineering. I believe this really helped broaden the understanding and potential beneficial application of this technology.”

3D reconstruction of MIRA scans showing dowel bars and an embedded strain gauge

Looking forward to the next phases of implementing the technology, Popovics says that they “aim to continue to work with IDOT to ensure optimal field application and analysis of the technology and data that is obtained.” He will be working with IDOT to create a training video on the MIRA, which will be a good way for employees to learn to use the device. TRP chair Douglas Dirks says “the Bureau of Bridges and Structures will take possession of the device, and it should be very helpful for many tasks such as locating reinforcement in very old structures where little information is available.”

While this phase of the work is concluded, Jeff Roesler does see some potential for future research in this area: “More research could be done on how to apply the equipment technology with multiple arrays of sensors to look at other problems not currently done such as the depth of a crack into a slab or bridge deck or reinforced concrete section. I think the research could now be focused on expanding the capabilities of the technology.”

Originally published May 22, 2017

Ongoing Study Seeks to Improve Hot-Mix Asphalt Performance

Published April 1, 2017

In an ongoing effort to maximize performance of hot-mix asphalt (HMA) containing higher amounts of recycled materials, IDOT and ICT started a project entitled Construction and Performance Monitoring of Various Asphalt Mixes (R27-161) in 2014. This effort is part of a larger goal that aims to improve pavements built using recycled materials to enhance their sustainability. A second interim report on the project was recently publishedRead More

Speed Harmonization: ICT Research Helps IDOT Improve Safety on Rural Roadways

Published April 1, 2017

Current geometric design of roadway elements is based primarily on the design speed. The design speed is used by roadway engineers to design appropriate safety elements such as vertical and horizontal curves, stopping sight distance, and guardrail needs. On rural highways, operating speed is often higher than the design speed, which may become problematic from a safety standpoint. In rural settings, there are also more free-flowing traffic conditions with limited enforcement opportunities. These circumstances often lead to increased crashes.Read More

IDOT’s Research Reset

Published April 1, 2017

The last year has been very eventful for IDOT’s research program, with many changes and opportunities.

The current intergovernmental agreement between the Illinois Department of Transportation (IDOT) and the University of Illinois’ Illinois Center for Transportation (ICT) expires on June 30, 2017. Over the past 18 months, IDOT and ICT have been collaborating on a new agreement to allow IDOT to continue its long association with ICT to administer and manage the department’s state-level research program.Read More