You’ve heard it takes a village, but for Century Asphalt Materials, it takes a terminal.
Century Asphalt Materials provides Southeast Texas with hot-mix asphalt (HMA) and warm-mix asphalt (WMA) products, four sealcoat products, and eight construction aggregate products. To meet the need of base materials, Century Asphalt Materials operates 13 HMA plants and a concrete crushing plant located throughout Houston and the Hill Country of Texas. A second concrete crushing plant is being added in the Greater Houston area. And since 2011, the company operates a terminal for bulk storage of liquid asphalt to stay cost-competitive.
According to Bill Lee, terminal manager for Century Asphalt Terminal, the hub allows for the purchase of liquid asphalt when it’s at its lowest cost point.
“With more than 300,000 barrels (35,772,141 l) of storage, we’re able to make purchases when the cost of liquid asphalt is lowest, said Lee. “The price of liquid asphalt can fluctuate and having adequate storage reduces our material cost and allows us to make lower bids and win more jobs.”
THE TERMINAL PROJECT
Century Asphalt Materials turned to Heatec, based in Chattanooga, Tennessee, for the expertise and equipment to make the terminal a reality.
“Heatec personnel did the engineering and programming,” said Lee. “We got the whole package from Heatec instead of having to go out and subcontract.”
According to Heatec, the project was developed from scratch; no existing structures were used or refurbished. The site includes six 54,000-barrel (9,072 tons/2,268,000 gal/6,438,985 l) inventory tanks, two 5,000-barrel (840 tons/210,000 gal/596,202 l) day tanks, and two 10,000-barrel (1,680 tons/420,000 gal/1,589,873 l) day tanks, as well as the piping and heaters to bring in, heat, store, transfer, load out material, and more.
The barge unloading system from Heatec provides asphalt piping from Century Asphalt Terminal to a dock on the Cedar Bayou Waterway. It consists of the following:
Approximately 1,800 ft (548 m) of 10-in (25.4 cm) asphalt piping from the dock to the plant site, plus another 1,200 ft (365 m) of piping to the last tank.
The piping has 11 expansion loops and three bridges, which also serve as expansion loops.
All of the asphalt piping is heated with oil tracing exept for the dock line piping; once it leaves Century’s property, it is heated with electric tracing.
Unloading rate is 1,600 GPM (6,055 l/min).
The dock has a 20 ft x 30 ft (6.09 m x 9.14 m) steel platform and a hose crane.
“At the dock, we would bring in a barge holding up to 20,000 barrels (2,384,809 l) of asphalt,” Lee said. The pump for moving the liquid material is aboard the barge, but a Century Asphalt crew member hooks up the hose from the dock. “We have about 3,000 ft (914 m) of electrically traced piping going back to the terminal,” Lee continued. “Typically it takes about 8 to 12 hours to unload each barge.”
Liquid material is delivered by rail from the north. Approximately 80 to 120 rail cars a month are brought in, each one of those carrying about 500 barrels (59,620 l) of asphalt. Century Asphalt Materials invested in loadout structures and automation from Heatec to make the system as user-friendly as possible.
The pipe rack holds all the piping necessary for moving materials between the tanks and for unloading material from the rail cars. It also carries the hot oil through the system for heating the tanks, as well as the piping.
The automated truck loading system is run with Astec programming for ease of use, allowing the truck drivers to load with a series of steps. The process can be done without terminal personnel at any time.
“The automated truck loading rack at the terminal has two active scales,” Lee said. “Trucks pull onto one of the scales. The driver chocks the wheels of the truck [as a safety protocol—this practice alerts personnel if there’s any movement of the truck]. They go upstairs and lock down a safety bridge. They go inside to answer a series of questions. They use their loading number to unlock the system. Then one final safety stop—they have a pedal they have to step on to be able to load the truck. The entire process takes about 25 to 30 minutes from start to finish, which means we can load somewhere around 80 to 90 trucks per day, depending on arrival times of the trucks.”
According to Lee, three expansion projects with Heatec are slotted to be done over the winter: adding 20 additional rail slots; adding rail loading capabilities; and adding polymer-modification equipment.
“We see this terminal as an evolving process. As we get used to the processes that we already have capabilities for, we’re adding new capabilities and expanding the terminal.”
Heatec designed pipe, pipe racks, and routings.
Truck loading station with Astec programming for the automated system.
Heatec designed the rail unloading station with piping to heat the railcars for unloading asphalt.
Heatec steam generator to provide steam for railcar unloading.
Dock with platform to unload barges.