Located on the far northwest side of San Antonio, Vulcan Materials Company’s Helotes facility has been serving the San Antonio market for 30-plus years.
Vulcan- one of the nation’s largest producers of construction aggregates and a major producer of aggregates-based construction materials, including asphalt and ready-mix concrete- has 342 sites that produce construction aggregates, and about 100 facilities that produce asphalt and/or concrete. All of these are located in the U.S. except for their quarry and marine terminal on Mexico’s Yucatán Peninsula.
Recently, the Helotes Quarry facility purchased a new Gencor asphalt plant to replace its 20-year-old Cedarapids plant. The plant was erected in September 2013 and went on-line in November 2013.
The new plant is one of two Gencor plants at the location. Its newest unit is a 400-tph Ultraplant featuring Advanced Rap Entry (A.R.E.). The other plant is a 500-tph Ultraplant A.R.E., says Justin Stumberg, asphalt ops manager at Helotes Quarry.
“The Helotes location is always very busy producing hot mix and stone,” he says. “Having two plants at one location allows us to serve our customers with excellent availability, 24/7 on many occasions.”
Gencor’s Ultraplant is built with patented counterflow Ultradrum technology. The A.R.E. concept uses the gases and convective heat of the combustion zone to preheat and advance the release of internal moisture in the recycle pavement. This advanced release of moisture results in higher production due to a more even and staged release of water vapor in the drying process using less energy by not super-heating the virgin aggregates.
Complicated mix designs
“Vulcan Materials prides itself with meeting any and all complicated mix designs as well as traditional TXDOT mixes,” says Stumberg. “We have had many opportunities to test and produce new and challenging mixes.”
The Helotes Quarry facility serves TxDOT as well as commercial and municipal clients.
The new plant features seven cold feed bins, three recycle bins, and three 200-ton silos. “This allows us to make multiple mixes on the fly with flexibility,” says Stumburg.
The plant is also outfitted with the Ultralogiks plant control system, a totally integrated automation package that manages and monitors all plant control functions with a windows-based environment and graphical user interface.
The hardware is an advanced PLC control platform that performs all the plant operations, including both blending and loadout functions. The graphical user interface is PC-based, using a high-speed IBM compatible computer with a large capacity hard drive. A backup computer and redundant hard drive assure complete security of the data and operating system in the event of a failure of the PC or the PLC.
The Ultralogiks main operating screens display a logical presentation of operating data through the use of segregated screen sections. The upper section displays items at the point of liquid asphalt injection; the center section offers selectable views of Motors, Maintenance, or Event Log information as well as configuration settings and calibration screens. Detailed user screens for each equipment component are displayed by simply clicking on the equipment image.
“This is the most up-to-date and, in my opinion, the most advanced but operator friendly control system available,” says Stumberg. “This system allows for optimum blending automation, and we can see every little thing happening with the plant in real time.
“This allows for excellent preventive maintenance data because the system shows accurate digital motor amperages and limit statues/position at all times,” he continues. “The multiple monitors allow for ease of operation with maximum data. The system is also very easy for new operators to learn.”
Recycled materials – reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) – are becoming standard for asphalt producers across the country. The Helotes Quarry location elected to purchase the additional RAS feature for its new Gencor Ultraplant.
“RAP and RAS are separated into two entry collars,” explains Stumberg. “The RAP enters the first ‘uphill’ collar, and the RAS, with dust return, proceeds into the second ‘downhill’ collar.
“This allows for the RAS to become lubricated with the dust to reduce recycle build up in the drum,” he says. “The largest benefit, however, is that the RAP and RAS are weighed individually on two separate belts, which allows for much more precise control of metering the recycled binder.
“RAP and RAS have two extremely different mix percentages with two extremely different AC contents,” he continues. “If you were to weigh/meter both products on one belt, you could have a big variance of total AC (recycled and virgin binder) in your hot mix. By separating the two, we have complete control of the exact recycled AC binder we are adding to the mix. This results in a very consistent workable mix.”
Even with the latest technology available at his asphalt facility, Stumberg admits the most important key to success are his employees. “Our number one asset is our people,” he says. “We put a lot of effort into our safety programs to assure everyone remains safe. We also work hard on employee development, through training and mentoring programs.”
After employees, customer satisfaction ranks high on the list. “Meeting our customers’ demands with a quality product that both of us can highly appreciate is very important to both me as an asphalt operations manager and Vulcan Materials,” says Stumberg. “We consider ourselves to be good stewards in the industry and care about providing an excellent product that builds good roads and parking lots.
“Consistency is the name of the game,” he finishes. “Through your people, customers, plant mechanics, and mix design.”