From Astec Industries, Edited by Sandy Lender
Superior Paving Corporation of Virginia located a new asphalt plant in Bull Run, just west of Washington, D.C., and about five miles from one of its existing plants. Everything about the installation was strategic. From its location to its recycle capabilities, this plant is positioned for the future.
The new plant is an Astec Double Barrel XHR rated at 500 tons per hour and designed to run high reclaimed asphalt pavement (RAP) mixes. It’s one of 10 plants the company can boast to support eight paving crews working on projects for the Virginia Department of Transportation (VDOT). But the plants also provide about 25 percent of their overall mix for independent contractors working on commercial and private projects. You see, VDOT allows up to 35 percent RAP content in base course mixes and up to 30 percent in surface. The new plant in Bull Run should let the company hit up to 60 percent RAP content in mixes.
“We decided to go with a high-RAP capability to accommodate any future increase the DOT may allow, as well as having the ability to serve private projects that will allow a higher RAP content,” Mark Painter said. He’s the general manager of asphalt plants for Superior. He spoke about the breakout of supply and demand.
Painter has been with Superior since 1990, and has been the manager of all the asphalt plants since 2007. He said 75 percent of asphalt produced at the company is placed by the company’s paving crews, with the remainder sold to independent paving contractors. Superior maintains a fleet of 60 trucks to get mix to its projects, and will hire an additional 20 independent drivers during peak paving operations. The company also supplies mix to about 20 different paving companies who loadout daily.
“Seven of our 10 plants are Astec, and most of our plants can produce mix with as much as 50 percent RAP content,” Painter shared. “We have produced mix with as much as 40 percent RAP for private projects, so we decided to invest in a plant that can produce high-RAP mixes, because we believe RAP usage will continue to grow as government agencies and private customers see the value and performance advantages of using RAP mixes.”
Eighty percent of Superior’s recycled asphalt material comes from its own milling operations. Most projects only require the top surface course be milled off before a new surface can be placed. The old, oxidized material is hauled back to one of Superior’s plants to be crushed, separated and eventually added to new mixes used in base or surface mix designs.
The reason for locating the new plant in Bull Run also involves the future. It’s situated about five miles from an existing plant, which is located in a quarry that will be shut down in several years.
“We know that plant will have to be re-located to one of our other plant [sites], so we wanted to get this new plant running to prevent any disruption of production in this part of our market,” Painter explained.
Even though the new plant is “close” to an existing facility, Painter explained that it’s across county lines and required its own permit. He said the permitting process went pretty well. The plant is holding up its end of the deal for the permit, too. In early December, it underwent stack and Department of Environmental Quality (DEQ) tests, according to Painter.
“There were zero issues with it,” he said. “Everything went great.”
The relocatable 500-TPH Double Barrel XHR drum mixer is fired by a Phoenix Talon 125 MBTU/hr combination burner. Superior elected to equip the plant with an Astec twin shaft mixer for maximum binder coating during mixing. It includes an Astec Green System for warm mixes, Painter shared. The drum is fed by eight cold feed bins and three RAP bins.
“There are so many mix designs required to meet agency specifications and if a bin goes down, we just wanted to make sure our feed systems would keep our drum supplied,” Painter said.
The team Painter commended for the work of making all that mix includes Billy Eversole and Wayne Mills. Eversole is the plant operator, who has been with the company for four or five years now. “This was a brand new system with no push buttons,” Painter said. “It’s all computers, and he picked it up very well.”
Mills is the foreman, who has been with the company for about 11 years now. Painter spoke of Mills’ ability to keep everything moving smoothly bringing the plant up to speed.
Other significant components for the new facility include three 30,000-gallon vertical Heatec liquid asphalt binder tanks heated by a Heatec gas/oil fired oil heater, a 20,000-gallon vertical tack tank, a 20,000-gallon vertical emulsion tank, and a 23,500-gallon vertical #2 fuel tank to supply the drum burner as well as the dump trucks.
A 95,892-CFM pulse baghouse filters and recycles dust from the aggregate supply back into the mix production. The entire plant is managed from the pilot control center with a TCII HMA PLC control system.
This new plant includes the Astec V-Pac stack temperature control system, which features variable speed drives (VSD). Painter explained, “We went with VSD on our drum to control the stack temperature and a VSD on the mixer to have better control when adding binder in the mixing process.”
Painter said they’ve had the plant up to its full 500 TPH and it “performed great” for them. “We believe it will be a great addition to our other production facilities.”