Concrete Plants For Sale

About Concrete Plants

Concrete plants, also called “concrete batching plants,” mix cement powder (a binder) with coarse and fine aggregates (sand, gravel, crushed stone) and possibly precise amounts of water, depending on the type of plant. Different mixtures, additives, and mixer types make concrete suitable for roller compacted concrete (RCC), pre-cast, and prestressed applications.

Dry Mix vs. Wet Mix Concrete Plants

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Cemco Model 275 Mobile Concrete Batch Plant

There are two major types of concrete batching plants. A dry mix (or ready mix) plant produces concrete in powder form with a uniform dispersal of ingredients. After offloading the dry mix to a concrete mixing truck, water is added either on the way to the job site (called transit mix) or at the site itself, whereupon the mixing drum mechanically agitates the powder and water to the right consistency. An advantage of dry mix is the fact that a concrete plant can serve distant sites without the time constraints of wet mix, which must be poured within a certain amount of time.

A wet mix (or central mix) plant adds a precise amount of water to the powder in a central concrete mixer right there at the plant. The water is either weighed or measured by volume. The resulting wet mix is then dumped into a mixer truck and agitated along the way to keep it fluid until it reaches the jobsite. Wet mix sites have an advantage in precision control of the mix. They also don’t require dust collection systems at the truck loading point as do dry mix plants.

Concrete Plant Components

Concrete plants have a number of moving parts. The cement bins or batchers are silos for dry cement powder such as Portland cement. The aggregate bins or batchers, which may have multiple compartments, similarly store pre-mix dry components. Ingredients can vary, including slag, fly ash, expanding agents, mineral powder, potash, silica fume (fine particles), and so on according to the desired specifications of the batch. The bins can be filled by a radial stacker, an incline feed conveyor with a turn head, or individual conveyors for each bin. The tops of the silos may have dust collection systems in place.

Next, dry powder from the cement silos is transported to a powder weighing hopper or belt, such as by screw conveyors. The weighed ingredients are dumped into a mixer. Mixer designs vary according to the application, and some can be used for either wet or dry applications. Tilt drum mixers—as found on mixer trucks—and single- or twin-shaft horizontal shaft mixers are common. RCC mixers are optimized for roller compressed concrete formulation. Pan and planetary types of mixers are suited to precast concrete production.

An admixture may be added to the mixer through a manifold to affect the mix’s drying rate, make self-leveling concrete, or add other properties. Temperature is important in a concrete plant, so there may be components such as water chillers for production in hot weather, water heaters for cold weather, and even bin heaters to keep the aggregate from freezing.

Stationary vs. Portable Concrete Plants

A stationary concrete plant is a relatively permanent facility set up for long-term production. It’s the more expensive type of plant, but also the most efficient and productive in terms of cubic yards per hour. A stationary plant’s components may come on trusses for relocation, but most are set up on piers or a slab.

A mobile or portable concrete plant operates under the same general principles, but comes on a number of trailers or skids to be used on-site or even shipping containers to be sent overseas. Manufacturer Vince Hagan claims to have invented the mobile concrete batching plant concept in 1956. The components are mounted directly on the trailers, which may tilt, deploy stabilizing feet, or be hoisted into position by a crane during assembly of the plant. Some mobile plants are self-erecting, meaning they don’t require a crane to help assemble them.

Modern Features

Component manufacturers strive to improve concrete plants to reduce their cost per yard and increase the precision of each mix. Advancements in weighing and metering have improved the accuracy of mix proportions, and other upgrades have allowed producers to support more types of mix and quickly switch from one to another.

Variable frequency drive (VFD) motors in conveyors, mixers, and other components have reduced energy usage and improved efficiency when the plant is running at partial capacity.

Find The Right Concrete Plant Equipment

FABO, Cemco, Frumecar, CON-E-CO, Liebherr, and Vince Hagan are just some of the manufacturers of concrete batching plants and components.

You’ll find a variety of new and used concrete plants and components for sale at PavingEquipment.com.