|Portability • Versatility|
"Our old pugmill machines just were not keeping up with the crews in the field," said Mike Morganthaler, project manager for the Memphis Division of APAC-Tennessee. "So we went to the Astec people and asked them to design a production unit that the crews in the field would not be waiting on. And this is what we came up with." hen you think of astec, you probably tend to think of "asphalt technology," the phrase from which the name "Astec" was derived and the area where the company has become an industry leader. But when the Memphis Division of APACTennessee, Inc. needed an efficient way to create cement-treated base (CTB), they turned to Astec—a frequent equipment supplier for their asphalt operations—for a solution to their cement handling.
The CTB plant Astec developed is rated at 500 tph (454 tonnes per hour), with three cold-feed bins to allow the production crew to change mixes on the fly.
"We can run—on average—about 400 to 450 tph (363 to 408 tonnes per hour)," said Morganthaler. "If we really wanted to push the thing, though, we could probably get up in the 600 tph (544 tonnes per hour) range. Now—with this new equipment—we can produce whatever the crews out there in the field can handle."
Morganthaler was interviewed for this story in February. And at that time, he said that since the plant went into production in November 2002, it had produced 35,000 tons (31,751 tonnes) of material.
In addition to producing the normal material, Morganthaler said the Astec CTB plant can be used to make other kinds of mixes.
"Its main function is to make a cement-treated base, but we can also make a cement-treated drainable base and a cold mix with it," said Morganthaler. "And now we're kicking around the idea of a continuous-flow concrete, the kind that you would normally make in a central-mix plant."
The Astec CTB plant came with a portable 10 ft. x 14 ft. (3 m x 4 m) three-bin cold-feed system, a 30 in. x 50 ft. (76 cm x 15 m) inclined self-erecting conveyor, a portable 30 in. x 50 ft. (76 cm x 15 m) conveyor with a 500 tph (454 tonnes per hour) CTB mixer, a Process Mate control system, a 100 ton (91 tonne) portable selferecting surge bin, and a portable control house."The surge bin looks just like what you'd find in an Astec Six Pack HMA plant," Morganthaler said. "Then the surge bin was designed to sit on the load cells so the system can weigh out the material and automatically print out the truck tickets."
Morganthaler said he is especially impressed by the plant's portability and efficiency. And—given their plans for moving the plant around —portability is a key factor.
"It works great. It is completely portable. And it doesn't require any big cranes or big equipment to erect," said Morganthaler.
"Plus, it's built very heavy—it is incredibly stout."
This article originally appeared in Hot-Mix Magazine Vol. 15 num. 2