Zanesville-based Shelly & Sands Inc. is complementing its Hamm HD O90V with the new HD O120V to compact demanding pavements faster and at reduced costs on a job.
In late summer 2005 the firm had two HD O90Vs, one HD O120V, four HD 120HVs, and three HD 110VHV compactors.
In July, the firm acquired a new Vogele America Inc. 2219W paver, which complements two 1110 WBs and an 1110 RTB. A 1900 DC Wirtgen cold mill rounds out Shelly & Sands’ fleet.
All were sold by The McLean Company of Hudson, OH, a Wirtgen distributor.
“The firm is good to work with and is really helpful in getting technical information and getting parts to us on time,” said Steve Schlosser, equipment manager. “That makes a difference, because other distributors seem to be a little bit slower.”
Shelly & Sands’ intensive use of Hamms dates back three years, when McLean took on the Hamm account.
“We have lots of Hamms because they are good product,” Schlosser said. “The operators and mechanics like working on them, compared to other brands of rollers. It became time to upgrade our roller fleet — they weren’t doing the job that quality control needed out there — and Hamm got the call.”
Advantages Over Vibratory Rollers
“Vibratory rollers leave much the same impression; some have some advantages over the other,” said Ed Morrison, Shelly & Sands quality control manager. “But the oscillation rollers are providing a significant improvement on some of the tougher mixes, like our airport mixes and Superpave. Typically, on the jobs where we have had trouble achieving density, on intermediate or surface mixes, we have always seen better numbers using our oscillatory rollers.”
There are several reasons for this, he said.
“One is we have more time available for compaction,” Morrison said. “The oscillation roller lets us compact at lower temperatures, and it doesn’t seem to break the stone like a conventional vibratory roller will. Its ’kneading’ action gives us more time to compact, at lower temperatures.”
Oscillation compaction works by imparting a horizontal force into the hot-mix asphalt, from side to side, rather than by forcing it downwards by an up-and-down motion. The drum never leaves the mat.
Unlike traditional vibratory compactors that achieve compaction by bouncing the drum on the ground, oscillation technology ensures that the roller drums maintain constant contact with the ground for faster, more effective compaction. In the oscillation drum of the HD O90V and smaller HD O70V, two eccentric masses turning in the same direction cause a movement around the drum axle; there are four eccentrics in the new HD O120V.
The movement changes its direction of effect during one turn so it generates an oscillating or rocking movement of the drum. Horizontal forces are transmitted from the drum into the pavement. The result is better compaction in fewer passes, with less vibration-related wear and tear on operators and surroundings.
“It gives us a big advantage in meeting minimum density specs, and possibly achieve a bonus,” Morrison said. “If the compaction density is marginal with the conventional vibratory, once you get down below a certain temperature you will not get any more compaction. You’ll just break the stone. The oscillation roller gives us more of a chance to get within the spec limits, and possibly achieve a bonus when an incentive is offered.”
In addition to successfully getting density on asphalt lifts that are past optimum temperature, Shelly & Sands’ oscillation rollers are solving smoothness problems as well.
“The oscillation compactors are helping us with our smoothness issues as well,” Morrison said. “Today’s new polymer-modified asphalt mixes set up a lot quicker, and I feel we have a better chance of successfully compacting the mat and attaining optimum smoothness with an oscillation roller.”
Produce HMA At Lower Temperatures
Ultimately the oscillation technology may help save fuel and lower costs of asphalt production. Because the oscillation roller can compact effectively at significantly lower mat temperatures, the opportunity exists to produce hot mix asphalt at a cooler temperature, reducing emissions with the potential of large savings in energy costs, especially considering the size of today’s large asphalt plants.
“If you can drop the delivered temperature by 10 to 15 degrees, you can buy an oscillatory roller with the savings alone after a year’s time,” said Scott McLean, vice president and field sales manager of McLean Company’s Columbus, OH, branch. “Instead of mix coming out of the plant at 345 degrees, and running the risk of blowing your bag house out, with added wear and tear and production of excess blue smoke, you can drop the exit temperature to 325 degrees and perhaps delivered to the paver at 290, and the oscillation roller will still get density.”
Roller In Ohio
Shelly & Sands acquired the first oscillation roller in Ohio, an HD O90V.
“We tried it on a job with base mix and did not see a noticeable improvement,” Schlosser said. “Then we brought it back onto another job where we had some difficulty, and saw the numbers come up. We decided to rent an oscillation roller last year, and at the end of the season we decided to buy it.”
“On an airport job we put it out as a finish roller as we were instructed,” Morrison said. “That’s where we saw the most significant improvements. It brought the density up and the consistency as well.”
The Oscillation rollers also got Shelly & Sands out of a jam on U.S. 23 in Chillicothe, OH. The job requirements were two asphalt .47 in. (12 mm) lifts over joint-repaired concrete, but carried smoothness and density requirements.
Conventional vibratory rollers first were used to compact the material. However, joint repair bumps were reflecting through, so Morrison used Hamm oscillatory roller technology along with a pneumatic tired roller. Both worked very well in getting rid of the bump formation.
Shelly & Sands Inc. does more than asphalt paving; it’s a group of affiliated corporations which embraces new technology and — in the case of its Mar-Zane Materials division — wins national awards for the environmental excellence of its asphalt plants.
Founded in 1944, the first Shelly & Sands job involved a small paving crew of six men on a road outside of the tiny town of Dresden, OH. Today, Shelly & Sands serves eight major markets in four states and paves more roads in Ohio than any other company, the firm said.
Its first aggregate operation was purchased for $45,000 in 1946 and named the Muskingum River Gravel Company, after the rich reserves along the river. Now there are five facilities with extensive aggregate reserves.
Its Mar-Zane Materials subsidiary — so named in recognition of its Marietta-Zanesville roots — has 28 plants producing over three million tons of hot mix asphalt (HMA) annually, and five aggregate operations with extensive reserves.
This article originally appeared in the Fall/Winter 2005 issue of Wirtgen Technology.