What are the critical components to the paving train? Historically, the concrete contractor would typically mention the slipform or bridge paver, placer/spreader and the texture/curing machine. Off the top of his head, the asphalt contractor would probably point out the paver, rollers and rolling pattern, and probably the material transfer vehicle.
With today's more stringent ride standards and contract incentives being tied to smoothness, a relatively low-cost, high-tech tool is becoming an increasingly valuable part of the paving train. Both concrete and asphalt contractors are using Lightweight and High-Speed Profilers as in-process tools to help crews deliver a higher quality, smoother pavement surface, which helps the contractor to realize incentive payments.
"Smoothness has always been important for us and the industry as a whole," says Larry Shively, vice president of the Shelly Company, Thornville, OH. "The advent of profilers allows us to get profile numbers to our foremen quicker and with more accurate results, so we can deliver a better product to our customers."
A subsidiary of Oldcastle Materials, Shelly Company has more than 20 asphalt paving crews operating from four regional offices ? Twinsburg, Findlay, Columbus and the Thornville main office ? in Ohio. Currently, the paving contractor owns three Ames 8200 High Speed Profilers for the four regional offices. The profilers roam jobsites within a region to measure the profile of the pavements being paved by the crews.
The key to success
These machines are not just measuring the final numbers of the surface lift to ensure it meets the ride spec. No, Shelly Company's profilers are being used as in-process tools, measuring the pavement's profile after nearly every lift ? whether leveling, base or binder ? to ensure the smoothness numbers of the surface lift will be where they need to be.
"The profiler is a very important tool for our paving operations," mentions Shively, who is also responsible for quality control for Shelly Company.
The contractor has incorporated the use of profilographs and profilers into its paving operations for nearly a decade. Shelly Company started with the California type profilograph, but it quickly upgraded to the Ames Engineering Model 6200 Lightweight Profiler to speed up the pavement profiling process. More recently, the company has been using High speed profilers, which allow profile to be measured at highway speeds.
"Our profile crew drops in, does a quick analysis and gives the foreman the information to make any paving adjustments necessary," Shively explains.
These corrections can range anywhere from changes in the way a crew is unloading trucks to adjustments in the rolling patterns. The analysis has also helped Shelly Company to uncover pre-existing conditions in the road, which allows the contractor to go back to the project's owner early on to discuss possible changes in the pavement's design. In more extreme cases, the company may even bring in a mill on the base or intermediate lift to remove high spots.
The key is that Shelly Company uses the profiler as an in-process tool. The profilers not only help give the contractor smoothness numbers for the entire pavement, the software operating the profiler allows crews to pinpoint the locations of trouble spots.
"The technology allows the storing of information as fine as every inch of the surface," says Jon Klatt, sales manager for Ames Engineering. "Contractors can view International Roughness Index (IRI) numbers for specific areas in 50-foot increments."
Shively agrees with Klatt on the value of the spec area analysis of the profilers. "They are very helpful tools for conducting the forensics on the road. We can isolate problem areas and give our crews the necessary information to correct the issues," he adds.