With a full line of products and facilities at the ready, Chattanooga, Tenn.-based Astec, Inc. unveiled its newly formed Concrete Products Group at World of Concrete in February at the Las Vegas Convention Center. Known primarily as a supplier of asphalt facility equipment, Astec is offering individual components and full concrete plants as part of this launch, featuring equipment for a number of applications.
Heading Astec Concrete Products Group is Jim Johnson, whose 27 years in equipment includes positions with Caterpillar, CMI and Terex. He oversees a group whose offerings span:
A line of portable concrete plants is designed for quick set-up and easy transport. Operators can add pre-wired and pre-plumbed components to expand capacity as needed. And any dry plant can be converted to a wet plant with the addition of a self-erecting mixer platform.
Complete three-load plants and four-load plants are available with working capacities from 80 to 350 yd. for single mixers; dual mixer arrangements are also available. Air-bag suspensions give the equipment a smooth ride and allow the frame to be lowered to act as the foundation on a properly prepared grade.
The Astec twin-shaft mixer incorporates materials into a consistent, uniform mix. The design includes a proprietary automated wash-down system using pre-positioned nozzles inside the mixing chamber. Activated by computer or run manually, the system washes down the interior, allowing all materials to be flushed through the discharge gate. Access doors allow high-pressure wash wands into the mixer side-frames.
Aggregates are placed onto the collecting conveyor from individual feed bins in layers, allowing cement to be spread between these layers. Continuous, even distribution of material is delivered on fully-shrouded conveyers, through to the discharge head. The water distribution system delivers a continuous spray around the falling aggregates to produce uniformly wet materials.
The silo features a mass flow control system with weight change monitors feeding information to the microprocessor control. Both split-compartments and pairs are available.
ROLLER COMPACTED CONCRETE PLANT
Materials are managed with continuous blending using belt scales and variable-frequency conveyor drives with Astec roller compacted plants. Live aggregate feeding is handled with 30-ton bins, and two- to six-bin arrangements are available.
Throughout the rated production range, belt scales with weigh idlers and variable-speed drives result in precision batching. A load cell indicates the weight of the aggregates, while the computer controls adjust for the production rate.
Astec mixers are designed in-house and feature shaft-driven, high-torque, folding action, delivering a uniform mix. Like the portable plants, the roller compacted facilities' cement silos feature a mass flow control system with weight change monitors; air-bag suspensions give the silos a smooth ride and allow the frame to be lowered to act as the foundation on any grade.
This line of concrete plant equipment combines modular, clean structures with built-in stairs, decks and ladders, and interchangeable deck mixers with surge hoppers. Seismic designs also are available.
All towers are pre-wired with conduit, plugs and receptacles. Tower configurations allow for storage of cement and aggregates in a single tower, or twin towers, or a single tower with adjoining round cement silos.
A key component in the production tower with is the screening deck mounted at the top of the aggregate bins. Properly graded materials allow for exact consumption of cement for every mix design. Vibrating decks are standard and provided for each bin. Screens are long lasting and easy to access for maintenance. Additional decks and by-passes are available. Whether loader-charged conveyors or drive-over hoppers are used, the flow of aggregates is supplied by a vertical elevator, greatly reducing the footprint of the plant.
In wet mix configurations, Astec twin-shaft deck mixers are incorporated into the production tower using a modular section that is universally matched to the structure.
With computer-matched plant controls operators are assured of accurate speeds for aggregate blending. Continuous mix production is possible with the company's precision control systems, allowing high-volume production for CTB, RCC, and zero-slump PCC, using a surge hopper to control volumes and manage truck sequencing. All Astec control systems are programmed by in-house staff and serviced by a dedicated company department. Control houses are in-house designed and built with all switch gear and connections housed in a climate-controlled building for all-weather protection.
Û Astec Concrete Products Group; 423/867-4210; www.astecinc.com