Yellow and white redi mix concrete truck and mixer on snowy roadway

A Deeper Understanding of the Concrete Truck Drum

How well do you know the components of your concrete truck drum? Did you know that mixers and blades work together to serve two separate functions? Do you know what can happen when you allow too much buildup to accumulate inside — or the benefits of establishing an effective maintenance routine? General Chipping is here to answer the hard-hitting questions and supply you with tips for future practices. Read on to stay informed.

Man on ladder aiding with pour from a redi mix concrete truck
Understanding the tools your team uses for its work helps foster more efficient operations.

Elements of Your Concrete Truck Drum: Mixing and Dispensing
There are three general types of batch mixers out there, and concrete truck drums belong to the “rear discharge” — or reverse mixer — category. These truck drums come equipped with specific tools to aid in mixing, transporting and pouring concrete. Blades inside the concrete truck drum, for instance, serve two purposes: to mix and dispense your concrete blend. Transport trucks can mix concrete on-site or deliver previously mixed concrete to its final destination. When the latter takes place, those trucks transport material to the job site with help from one or more blades inside the rotating truck drum. The blades agitate the material through a process known as “charging” in order to prevent the concrete from hardening while en route. When all goes according to plan, the mixture is adequately blended — and is the appropriate consistency — upon arrival.

The truck blades’ work isn’t over once the crew reaches the job site. Once it comes time to pour, the driver reverses the rotation of the concrete truck drum to start the extraction process. This is where things get interesting. The spiral-like blades inside a traditional drum mixer (known as augers) were modeled after Archimedes’ Screw. The pump functions much like the helical blades in a concrete truck — the direction of the drum’s rotation against the blades will discharge the concrete mixture through a chute that leads to the pour site. As the truck driver expels the mixture, he or she relies on a designated “chuteman” to guide the freshly mixed concrete to its destination. If the truck can’t reach the site, pumps and conveyor belts extract the material directly from the mixing drum.
Fun Fact: Archimedes was a Greek mathematician and engineer who is thought to have invented one of the earliest hydraulic pumps on record.

Keeping Buildup at Bay
Remember to pay attention to your concrete mixture, so buildup doesn’t take you by surprise. These three simple tips can save your business time and money:

  1. Once your concrete is mixed, keep that drum moving. Watch for irregular movements in the drum’s rotation during the mixing process. Whether the drum is mixing or agitating your concrete, the rhythm should be free from lags. Irregular movements could mean mechanical issues and potential damage caused by buildup from previous pours.
  2. Check the consistency of your concrete. Dried material in your poured mix can diminish the strength of the concrete and indicate old residue from previous batches accumulated inside of the mixing drum.
  3. Lastly, never overfill your drums. The truck drum rating determines the maximum amount of concrete recommended for your vessel. This rating is an instruction — not a suggestion — for concrete truck drum operators and their crews.

Maintenance Considerations
Establishing a maintenance routine for your concrete truck drums prevents expensive repairs and, most importantly, unnecessary safety risks. Consider purchasing a chemical drum cleaner as a preventative measure. Of course, these cleaners won’t replace professional maintenance on your concrete truck drum, but they are a first step in the right direction.

General Chipping recommends scheduling maintenance appointments every three months to avoid long-lasting damages to mixing drums. Budgeting for regular assessments of your mixing vehicles can save you from incurring additional repair costs and help you financially prepare for maintenance costs ahead of time. If you’re experiencing any of the aforementioned warning signs or just want to take the necessary measures to prevent them, schedule your concrete chipping appointment today! Our team is here to help, and we’d love to hear from you.