HANOVER, N.H. (July 26, 2017) -- The U.S. Army Engineer Research and Development Center’s Cold Regions Research and Engineering Laboratory has drawn on and utilized a broad range of in-house capabilities to provide the lab’s trafficking tool, the Heavy Vehicle Simulator, additional capacity for testing pavements year round.
The Heavy Vehicle Simulator (measuring 75 feet long, 12 feet wide, and 12 feet high and weighing 51 tons) when testing can apply heavy loads, while conducting up to 10,000 passes per day simulating truck and airplane traffic.
CRREL’s ERB staff members Civil Engineering Technicians Charlie Smith and Andy Bernier have been working to modernize the HVS and other supporting equipment in order to conduct pavements testing more safely, reliably and cost effectively. The most recent upgrade involves two new systems for heating and cooling of the pavement test section under the HVS from 15 degrees Fahrenheit to more than 120 degrees Fahrenheit (minus 9 to 49 degrees Celsius) for year round testing.
This challenging HVS upgrade involved CRREL’s in-house design and fabrication of an infrared heating system. The IR Team consisted of Chris Williams, an electronic engineer, Chris Donnelly and Jordan Hodge, engineering technicians, all with CRREL’s ERB. This project presented numerous mechanical and electrical design, fabrication and installation challenges with each member having their respective part of the project.
“We improved upon on existing system used by others,” said Williams of the IR heater. “We made it better and more robust. The hardest part of this project was selecting and locating the parts. Once I was able to find the brand of the IR heaters that fit our criteria; I basically was able to work from there to try and save time.”
After selecting the IR heaters, Williams designed the system to existing electrical capacity. The system was based on a 208V AC, 100 amp, and 3-phased service. When running at full capacity, the heating system draws 32,000 watts of electricity.
The HVS’s IR heating system was designed with four heaters per side. Each heater has its own controller and sensor, which monitors the temperature of the pavement 2 inches below the surface, so that the overall system can maintain a constant temperature across the entire test section.
After the parts and pieces were designed and fabricated, Williams then led the assembly and functions testing at CRREL minimizing installation time where the HVS currently resides. Shortly after assembling the IR heating system, it was loaded onto an 8-foot truck bed and the team drove it to the location and fitted the new system to the HVS.
“Fitting the system to the HVS was actually quite simple,” said Williams. “There were no adjustments needed. We built at CRREL, transferred to the location and we attached the heating units, which fit very well.”
From beginning to end the new IR heat system took five weeks total – conceptual design, fabrication, machining and welding of the framework; the SolidWorks design (conceptual design, 3-D modeling and mechanical drawings) and construction of the IR’s framework, where the IR heater would be attached to the HVS; and the design of the electrical parts including the controllers, heaters, feedback mechanism and wiring of the system, which was the most time consuming taking three days.
The new system has been used in testing.
“We have received very favorable feedback indicating that the heating system was, and continues to be, successful,” said Williams.
“We were able to design and install this heating system at a third of the estimated cost of any potential contractors,” said Jared Oren, chief of the ERB.
Feedback to the lab has been positive.
Comments received from those currently conducting tests with the HVS, “The new infrared heating system is designed in such a way that a footprint of the pavement to be heated can be varied to optimize the heating intensity and time required to attain a temperature. The heating system can maintain the pavement up to 120 degrees Fahrenheit.”
Working to solve transportation challenges and providing systems that are built better, cheaper and providing the nation with safer roads is indeed keeping with ERDC’s values – CRREL is helping to make the world safer and better.