Road Rehab

Staff | September 28, 2010

H & S Construction Co. recently completed a small, yet very demanding asphalt "mill and fill" road rehabilitation project. The Lafayette, La.-based contractor had a $1.1-million contract with a 60-day completion deadline with the Louisiana Department of Transportation and Development (LADOTD).

The work called for H & S to mill, repair, resurface and, in some areas, widen a portion of Route 182 near Patterson. The contract also called for the contractor to perform the work while maintaining traffic at all times on the twisting, comparatively narrow road.

LADOTD Project Engineer Chris J. Lissard said, "The challenges were everywhere, caused primarily by the old 20-foot wide, two-lane road itself and the need to maintain at least one lane of through traffic at all times. There were simply just too many small businesses, residences and through traffic to totally shut down the road."

Because safety concerns were paramount, H & S Construction brought in its new Roadtec RX-900, a 950-horsepower cold planer for the milling work. With a standard working weight of about 95,800 pounds, the well-balanced RX-900 was milling out to 12 feet, 6 inches wide at one time.

The contract called for removing and recycling approximately 32,000 square yards of deteriorating asphalt from U.S. Route 182. The contractor then put back down 7,700 tons of Superpave hot mix asphalt. The rehabilitated road now has two 12-foot-wide travel lanes plus two 6-foot-wide shoulders.

The present Route 182 was originally built and designated Route 90 in the 1930s as a "state-of-the-art" concrete road. The road, at that time, followed the twisting course of the Bayou Teche with two 9-foot-wide lanes to meet the traffic needs of the day. When it was replaced with the new divided highway, the old road was partially modified, upgraded and redesignated. Over the years, in belated attempts to keep pace with traffic demands, some patching and partial overlays were made.

Before any milling was even begun, the contractor's crew set out traffic delineating safety cones well ahead of the day's proposed work zones. Flagmen were also placed out ahead of and behind the Roadtec RX-900 and moved along with it. Once milling was started, pilot cars convoyed vehicles through the work areas.

The first 4,200 feet of the project consisted only of a 20-foot-wide roadway. The remainder of the road had been previously widened to include two 12-foot-wide, non-divided lanes and partial shoulders on both sides. The old 20-foot-wide road was milled full width in two passes, and widened to two 12-foot-wide non-divided lanes. A total paving overlay was added including new shoulders.

To expedite the project timeline, the contractor stockpiled the milled material as it was removed at selected local on-site areas. This, according to Vice President Shannon Elliot, was done to reduce the number and cost of leased trucks rather than hauling it immediately back to the contractor's plant sites for recycling. An on-site loader rehandled this at a later date when the asphalt hauling trucks normally would have been making the return trips empty while putting down the overlay.

"We were entitled to retain 75 percent of the millings we recovered. The LADOTD retained the other 25 percent and used their share for highway maintenance," continued Elliot.

"It's no secret that we often spend as much time on logistical planning as we do on pursuing the jobs. Even then, our team must remain flexible at all times in order to cope with those unanticipated situations. Weather is normally no problem. The crews simply put on foul weather gear and keep on going. The exception to this is when in doing so it might endanger either our crews or the motoring public," he added.

"We are attempting to maintain the same 2-percent mainline slope and on the shoulders instead of the more normal 5 or 6 percent for the shoulders. This is being done because of the total number of asphalt and concrete driveways that intersect with the main road. The original road was laid out at a 1.3- to 1.7-percent slope, which will be changed to a full 2 percent slope," commented Chris Lissard.

Shannon Elliot amplified on this, adding that, "by milling at the 12.5-foot width with the RX-900 cold planning machine, we were able to complete the mainline milling in only two smooth passes instead of the more normal three or four cuts. This saved both time and money and required fewer leased trucks, while maintaining more accuracy.

"By using the accurate dial-in slope and grade elevation controls on the machine, a smooth, flat surface was established across the whole lane. The project engineer said that the machine 'was right on the money.' It was also easier for our crew to dial in the super elevations at every 50 feet while milling on a curve without having to stop the progress to manually change this — going from 2 percent to sometimes a 5-percent slope. The result of this was a smoother resurfacing mat because the paver was simply following the already established grade and slope.

"In using special combination Kennametal carbide teeth on the cutter drum, our crews were able to mill both the asphalt mainline and into the concrete driveways. The only change required, when the driveways were encountered, was that the operator simply slowed down the RX-900's forward speed a bit," added Elliot.

"It's a given in the industry today that you can't economically compete with yesterday's equipment. The technology is changing too fast. Even though there is an added cost, we must invest in the latest, most modern machines and we must employ crews that have the experience to get the maximum productivity from them. The LADOTD has bonus money available on many of its projects. This, however, is awarded for quality rather than simply for productivity," said Gerald Hanchey.

"Over the years we have owned and operated many various machines. However, few, if any, have performed as well or been as versatile and productive for us as our new Roadtec RX-900. I might also add the same thing is true of our recently purchased SB-2500 Shuttle Buggy and our new Roadtec asphalt paver," concluded the president of H & S Construction Co., Inc.