About Ready-Mix Concrete Equipment

Identification

• Ready-mix concrete can be mixed in a variety of ways. Concrete can be mixed with the truck mixers, and this type of concrete is called truck-mixed, or transit-mixed, concrete.
  Ready-mix concrete can also be mixed in a plant mixer, then moved to the drum of the truck mixer. These central mixing plants use a stationary mixer to partially mix the concrete. This type of concrete is called shrink-mixed concrete, since it reduces the volume of the concrete.
  The final type of concrete mixing used is called central mixing, or wet batch, concrete. Central mixing is cost-effective since it requires less wear on the truck drums. However, some plant mixers may require more maintenance, but they produce higher quality concrete due to the superior mixing.

Function

• Ready-mix concrete is usually delivered by trucks with rotating drum mixers. Drum mixer trucks are designed with a pair of blades that spin one way to mix the concrete, and then can spin the opposite direction to release the mixture. Although most concrete mixer trucks discharge concrete from the back, newer trucks feature front-discharge chutes. These front-discharge trucks require less maneuvering to place the concrete in the correct location.

Types

• Types of plant mixers include: tilt drum mixer, horizontal shaft mixers, pan mixers and slurry mixers. Tilt drum mixers are the most common and are known for their efficiency. Horizontal shaft mixers are good for producing higher-quality concrete products because of their powerful blending capabilities.

Benefits

• For smaller projects, the newer "mix mobiles" are popular. These volumetric mixers, or mobile concrete plants on wheels, offer freshly mixed concrete on demand. Contractors put in sand, coarse aggregate, cement, water and other additives to the belts and bins to create fresh concrete on-site. For smaller projects, customers can order more exact amounts when using the volumetric mixers. Often when using drum mixers, they must order extra concrete to ensure that they have enough for the project. Contractors also save money because this method produces less waste.
  Some contractors also buy specialized pumps for pumping ready-mix concrete. If customers need a concrete pumped in, contractors who own their own pumps are at a significant advantage. Contractors can also contract out their pumping services to other concrete companies without a pump.

Considerations

• For concrete equipment, preventative care is essential for good use. It is necessary to pressure wash, check and adjust the equipment as needed. Some contractors may buy used equipment because the costs of mixers, pumps and other equipment is quite high. However, a breakdown in equipment may irritate customers and cause a contractor to lose a valuable contract. New equipment may be worth the cost for its reliability factor.