About a year ago, we received a poor batch of ready-mix concrete. Fortunately, we had taken several cylinder samples. We did end up exceeding our concrete design specification, but it took longer than we had expected to cure, which resulted in scheduling consequences. Still, it could have been much worse. What would have happened if we prematurely loaded footings that had not reached their designed specification? What if the concrete never hit the required psi? Who’s at fault and who would be blamed?

What I learned from this experience is that it is critical to document everything about the concrete for a project - namely, the product type used, how it is mixed, and the water-to-cement ratio, plus a few other things that you might need to record, especially if using additives. When you modify a bagged mix by either adding portland cement, or a water reducer, do you now own that mix design? Are you charging your client accordingly for the additional liability that you are taking on by modifying bagged goods? Before answering such questions for your organization, you need a consistent means of mixing concrete, otherwise all the specs you document may be rendered unreliable.

Concrete Mixers

For us, it is important to have a mixer that is mobile and that’s electric. A substantial amount of our work, whether it is residential, industrial, or commercial, is indoor work, all of which has its own challenges. We need to make sure we can transport the unit to the work location,which may be down a flight of stairs, up a loading dock, or the like. We need to manage our indoor air quality, and sometimes we need to manage sound.

There are some awesome gas options out there that are extremely heavy-duty, and that might be the best mixer for you, depending on what you’re doing. However, for us, the gas options lack a lot of the attributes that we are looking for in a mixer. Small portable drum mixers have really been our only option, and they're certainly not perfect. In my opinion, they are disposable. They have always lacked the necessary power needed to mix concrete at a profitable speed. You can’t easily and accurately regulate how much water you are adding, without adding the extra labor cost of measuring out the water for each batch. If there’s not a conscientious amount of care taken to break open and dump each bag into the drum, they can produce a troubling amount of dust. Not to mention they can be tough and time consuming to clean, and you're left with a ton of cement-laden water to dispose of. When you add in the frequency of mechanical failures, it often ends up easier to use a wheel barrow and a shovel.

Meet the MudMixer

The MudMixer is an onsite concrete mixer made by a small, Texas-based company of the same name. We've been using one for almost a year, first renting one and about six months ago we bought one, and so far it has been an absolute game changer. The MudMixer is similar to a volumetric concrete mixer except that the water is added, and the concrete is mixed, in the chute, making it different than any other electric mixer on the market. Weighing in at only 145 lbs., it’s extremely mobile, and very easy for two people to load on the truck, and unload at the end of the day. Virtually the whole machine is made from 14-gauge steel that is powder-coated grey; it seems extremely robust, and heavy-duty.

At 145 lbs., the MudMixer proves extremely mobile. Two workers can easily load it on the truck, or more to the point, unload it at the end of the day.
At 145 lbs., the MudMixer proves extremely mobile. Two workers can easily load it on the truck, or more to the point, unload it at the end of the day.

MudMixer claims to be able to mix 40 bags per hour, and we have verified that. This makes mixing a whole pallet of 80 lbs bags of concrete an hour or so project. The MudMixer has a big splitter that runs down the center of the hopper that practically automates opening bagged material. When it comes to adding water, we’re running a garden hose to the mixer. Here there is a valve where we can control the precise amount of water saturating our mix, giving us consistent and uniform results. Cleaning is easy too, it has an onboard hose and only takes a few minutes. Typically, we are left with less than a full bucket of grey water.

Dust generated from bagged goods is still very much an issue, but not any worse then what we are already accustomed to. MudMixer is a professional grade tool, made to withstand the rigors of the job site, and it comes with a price tag to match: $2,995.00. If you mix 20, 30, 40 plus pallets of concrete a year, its going to be a no brainer; this tool will pay for itself quickly. Stay tuned for our 100,000-bags, long-term review, when we are going to see if this mixer is as durable and maintenance free as the manufacture claims.