- CAIT Main
- Infrastructure Areas
- Program Sites
- ANDERS - Automated Nondestructive Evaluation and Rehabilitation System
- BEAST - Bridge Evaluation and Accelerated Structural Testing
- CAES - Center for Advanced Energy Systems
- FMP - Freight and Maritime Program
- ICMP - Infrastructure Condition Monitoring Program
- IMG - Information Management Group
- LESS - Laboratory for Energy Smart Systems
- LPS - Laboratory for Port Security
- LTBP - Long-Term Bridge Performance Program
- NJ LTAP - NJ Local Technical Assistance Program
- PRP - Pavement Resource Program
- PSSP - Pipeline Safety and Security Program
- SAM - Structures and Advanced Materials
- SSML - Soil and Sediment Management Laboratory
- TSRC - Transportation Safety Resource Center
- TTG - Technology Transfer Group
Revolutionary RABIT™ Bridge Deck Assessment Tool
Next time you’re on the New Jersey Turnpike, a highway in Virginia, or a bridge in Washington, DC, you might see RABIT™ gliding, not hopping, down the road. The American Society of Civil Engineers (ASCE) deemed this creation so revolutionary that they selected it for the 2014 Charles Pankow Award for Innovation.
The RABIT™ Story
CAIT and FHWA invented the RABIT™ bridge deck assessment tool, the first fully automated device that simultaneously gathers quantitative data using several nondestructive evaluation (NDE) technologies and melds it into a comprehensive diagnostic representation of concrete bridge deck condition. The benefits are many, but the ultimate value is its ability to help bridge owners make better-informed decisions regarding maintenance, repair, and rehabilitation of vital infrastructure. Candidates for the Pankow Award must be collaborative efforts that incorporate innovative design, materials, or construction-related research and are market-ready or commercially viable. In addition, winners have to show they will have a positive impact on the construction industry by reducing costs, waste, delivery times, worker injuries, and/or pollution and that they will increase safety and durability. RABIT™ meets all those criteria in spades.
In 2011, FHWA Administrator Victor Mendez challenged FHWA’s Long-Term Bridge Performance (LTBP) Program and CAIT to develop a system that would enhance and streamline condition assessment of the nation’s bridge inventory. (See Transportation Today Issue 11, January 2013) The team set to work, conceptualizing a way to deploy multiple NDE tools that have proven effective for detecting and characterizing the biggest culprits in bridge deck degradation: corrosion, delamination, and concrete quality. They wanted their invention to operate autonomously so it could systematically collect data faster than manual NDE methods, but without compromising data integrity or resolution. The end product had to link the data points with their exact location, merge the data from all the different NDE tools, and deliver a comprehensive picture of deck condition—inside and out—in real time. Safety, efficiency, and ease of operation had to be part of the package as well.
It was a tall order, but about a year after Mendez’s challenge, in November 2012 RABIT™ made its public debut and functioned exactly as it should. Mendez and the other FHWA dignitaries there to witness its unveiling were duly impressed. Said Mendez, “This is what we’ve been talking about at USDOT and FHWA—it’s about innovation and bringing solutions to the real world. … It’s so important that we’re able to solve problems today, not five years from today. … What you have done here is really, really amazing.”
Since that demo on a bridge that carries Route 15 over Route 66 near Haymarket, Virginia, the team has been refining RABIT™ and putting it through its paces.
Dr. Nenad Gucunski, who heads up the Rutgers’ CAIT team, says they’ve had transportation agencies from around the country asking to use RABIT™ to test their structures. It has done scans on bridges in New Castle and Dover, Delaware; Middletown and Mount Joy, Pennsylvania; Leesburg, Virginia; and on the New Jersey Turnpike and other highways in the state. FHWA estimates that to catch up on the nation’s deficient bridge backlog by 2028, we would need to invest $20.5 billion annually. It’s unlikely federal, state, and local governments can increase bridge investments by $8 billion a year—$76 billion total—to improve and keep all 600,000-plus bridges across the United States in good repair. So bridge owners and managers have to be especially vigilant about monitoring bridge condition and judicious with maintenance and rehabilitation budgets.
Traditionally, they have relied largely on the finely honed senses of experienced inspectors who use manual methods, such as chain drag and hammer sounding, to supplement eagle-eye visual inspections. But in the past several years, the growing use of NDE—technologies that help us actually see inside the structure—has provided bridge owners and managers with quantitative data that lets them “dig deeper” into bridge deck issues without actually digging up the roadway. NDE not only can catch potential problems earlier, it can make assessments more quickly, which in turn lessens traffic disruptions due to lane closures and improves safety by reducing the time both drivers and workers are exposed to the risks inherent in any work zone.
According to development team leader Gucunski, “In the past, we didn’t have a way to compile information on delamination, degradation, corrosion, precise location, visual, or load stress data all at once. Not only does RABIT™ help us validate data collected from individual machines, but it forms a meaningful picture of what’s happening inside the bridge deck in real time to help us arrest deterioration.”
The area to be scanned is preprogrammed with a highly accurate GPS unit, eliminating the previously necessary and tedious step of manually marking a test grid. It can be controlled remotely by smartphone or iPad, so the operator doesn’t have to be in traffic. In addition, its internal laser scanning system prevents collision with barriers, vehicles, and people.
“With our platform, we’re able to tell bridge managers exactly where they need to apply repairs so they can do so more quickly and efficiently. In addition to reducing the cost of assessing deck condition and the time it takes to do it, this reduces lane closures, doesn’t hinder businesses or frustrate drivers, and helps keep everyone safer,” Gucunski said.
RABIT™ could bring about the most radical change in bridge deck condition assessment that the industry has seen in the last 50 years. CAIT and its partners are confident that qualifies it as a great leap forward.
Photos 1, 2, and 4: ©Drew Noel Photography/Rutgers CAIT
Photo 3 and in table below: ©Nenad Gucunski/Rutgers CAIT
Snapshot of RABIT™ Benefits
Provides quantitative condition assessment of concrete bridge decks. Uses multiple technologies to detect and characterize surface and internal deterioration such as delamination, corrosion, and degradation.
Simplifies data interpretation. Data integration and visualization provide an intuitive, comprehensive picture of deck health.
Improves speed of data collection and analysis. Gathers data four times faster than individual NDE tools. In real time, information is wirelessly transmitted and compiled for review in RABIT™’s mobile command van.
Reduces costs significantly. Lessens time required for thorough inspection and number of technicians needed on site, increasing productivity.
Improves safety for workers and drivers. Faster data collection and fewer onsite personnel reduce risks inherent in any roadway work zone.
Minimizes negative environmental impacts. Alleviates work zone congestion and resulting traffic emissions and runs on clean, rechargeable batteries.
Global Positioning System records and tags all data gathered with exact position coordinates and orients/guides the robot.
High-Definition Imaging captures detailed images of the deck surface and 360-degree views of bridge features.
Ultrasonic Surface Waves assess the quality and modulus of elasticity, indicators of the strength of the concrete deck.
Impact Echo detects and characterizes delamination (horizontal cracking) with respect to depth, spread, and severity.
Electrical Resistivity diagnoses the corrosive environment within concrete decks by detecting level of moisture.
Ground Penetrating Radar is used to detect suspected flaws or characterize apparent deterioration.
FHWA Turner-Fairbank Highway Research Center
Center for Advanced Infrastructure and Transportation (CAIT)
Rutgers Team Leaders
Rutgers Faculty Contributors & Team Members