While the economy continues to challenge the construction industry, concrete producers are using the pause to improve operations. Plant managers are considering the benefits of central mix production as they focus on plant upgrades and modifications that improve quality, decrease energy use, and/or increase operating efficiencies. So even in downturns, there are good reasons to continue spending money to improve plant equipment, especially concrete mixers.
As engineers accept performance-based specifications, producers must raise their standards for mix designs. Producers will be challenged to create more mix designs on a dime. Many recipes will require greater precision.
Along with greater precision, producers must also consider the complexity of their work. Mixing concrete is no longer a three-part process: Add cement, aggregates, and water, and stir. Some performance mixes feature blends of cements, pigments, and aggregate combinations. More producers now use specialty admixtures to offer pervious concrete, roller-compacted concrete, and self-consolidating concrete. To meet these challenges, they are increasingly turning to central mix plant technologies that feature high-intensity mixing options.
The new mixing equipment can also be more energy-efficient. High-intensity mixers can thoroughly blend a concrete mix while operating without exceeding peak electrical demand. As truck fuel prices increase relative to electrical costs, producers can opt to spend their money on electricity, rather than fuel.
To help producers take advantage of these opportunities, the following are some of the newest advances in mixer-related technology. Circle the numbers on the reader service card for more information.
Single-shaft batch mixer
Available in 60-, 80-, and 100-cubic-foot models, the EM mixer is designed to produce dry cast products such as CMUs and pipe. It can provide a high-speed, homogenous mix in one to two minutes, depending on material absorption factors. Its user-friendly design is easy to operate and requires little routine maintenance. Besser Co. 800-968-0444. www.besser.com.
Reversing drum mixer
The RollMaster is mounted on solid urethane wheels, and its reversing drum mixer does not tilt. It rotates forward at full speed for charging and mixing. Ring gears and gear head motors are eliminated on this heavy-duty mixer. Its blade shovel system provides efficient charging, mixing, discharging, and easy cleaning. Available in 4- to 14-yard capacities. BMH Systems. 450-449-4770. www.bmhsystems.com.
Twin-shaft mixers
Pro and Heavy Pro twin-shaft mixers are designed especially for precast concrete that requires large volumes of different concrete recipes but maintain homogenous quality. Both styles feature two parallel shafts with scrapers at both ends and central mixing arms. The mixers come in five models (1.5-3.2 cubic meters) that are fast-filling, with short mixing cycles, quick discharge, and little need for maintenance. Elematic. 262-798-9777. www.elematic.com.
Planetary mixer
Entirely designed and manufactured in the U.S., the counter-current rotating action of this mixer's mixing arms can produce a homogeneous batch of concrete in 30 seconds. Features include cast Ni-Hard mixing paddles, urethane guards on the mixing arms, and a sealed gearbox. The mixer is available in .5-, 1-, 1.5-, 2- and 4-yard sizes. Mixer Systems Inc. 800-756-4937. www.mixersystems.com.
Abrasion-resistant castings
NiHard and HiChrome castings are the standard for concrete mixers and concrete pipe machines. At the forefront of chill-cast techniques and cryogenic treatment, the castings are warrantied to provide the longest service possible for white irons with internal integrity, the finest carbide matrix, and alloy economy. Texaloy Foundry Co. 800-367-6518. www.texaloy.com.
