Concrete Curing Formula: Water Plus Time
No matter the size of your concrete project, it’s important to keep the concrete curing process in check.
While water is a critical part of the short list of concrete ingredients, it is also, in collaboration with time, the enemy. Water activates the mix and starts both the concrete curing process and the clock.
With ready-mix concrete transported in a drum mixer, once water is added at the batch plant, any number of variables can delay the transport of a load to the jobsite, not to mention putting it in place once it’s on site. The longer that delay, the more risk there is the concrete won’t be acceptable when it arrives.
Factors That Eat Up Your Concrete Cure Time
There are so many things you can’t control when it comes to concrete projects. How far is it to the job site? How heavy is traffic? Is there construction that can slow delivery? What’s the weather like? Will the on-site crew be ready to put the load in place upon arrival?
With water on board and concrete cure time ticking away, the drive to the job site starts. The longer it takes to get the concrete to its destination and start pouring, the more difficult it is to place. As the mix cures and sets up, it gets thicker, which makes pouring it, placing it, and finishing it more challenging by the minute. To combat that, the only option is to add more water; and as volume of water goes up, the concrete’s strength goes down.
It seems that ready-mix trucks are notoriously late, and when that’s combined with over-cured concrete that doesn’t meet expectations, it simply compounds the delay, making for a longer day and putting the overall project schedule at risk. Combined with the need for the driver to take the time to dump what is now a waste product, clean up the rig, add to the wash out cleanup to be done later, then arrange for another truck to load up at the plant and make its way to the project site, costs quickly mount. We won’t even touch on the worst-case scenario, where concrete completely sets in the truck’s mixing barrel and someone must go inside it with a jackhammer to break it all up and remove it.
Controlled Concrete Mix Design to the Rescue
With concrete projects, like many things in life, you get the best results when you focus on the things you can control, while making plans to eliminate or at least mitigate the things you can’t control. One option to eliminate several troublesome variables, while radically increasing the list of things you can control when mixing and pouring concrete is to use a volumetric concrete mixer rather than ready-mix concrete delivered in a transit mixer.
Instantly, distance to the job site and road and traffic conditions along the way are no longer of concern. Weather is less important. It simply doesn’t matter how far or how much time it takes to get the truck to the job site.
Careful control of the concrete curing process is much simpler and more complete, from the very moment water is added until the last of the finishing is complete. Mixing the final product on site, as needed, eliminates concern over how much curing has already happened, and whether the pre-mixed concrete, which may have left the plant an hour ago or more, meets specifications and expectations.
Volumetric Mixers Love Challenging Job Sites
These concerns are present in even the best scenarios. They are especially critical when a job is in a remote area or is difficult to access. This is where volumetric mixer trucks are particularly appealing, because it doesn’t matter how long it takes for them to get there. Once there, they make fresh concrete at any volume that’s needed. Building on a mountain, or a beach, or some other isolated spot? Volumetric mixing is your ideal solution.
When you’re dealing with ready mix, you test it upon arrival, of course, before placing it to be sure it will perform as needed. If it doesn’t pass the test, you reject it and wait on a new batch, wasting time, materials, and the opportunity to keep the on-site crew productive and the project on time.
Volumetric mixing on site also eliminates guesswork, no matter how educated it may be, around how much concrete any project requires. When the last of the needed ready mix is placed, any left in the mixer truck is over cured and of no use. With volumetric mixing, wasted concrete is all but eliminated, because the precise amount of concrete required is mixed on-site, on-demand, the moment it’s needed.
If the on-site crew isn’t ready to place the concrete when the volumetric mixer truck arrives, no problem. It can wait however long they need it to and start mixing at any time. The concrete will be ready when they are, no sooner, no later. The exact amount needed, in exactly the formulation that’s been ordered, can be created and put in place, precisely where it’s needed, in minutes.
More Control, More Flexibility, Less Stress
With precise control over component proportions, additives, and more, volumetric mixing has the flexibility to change the type of concrete being mixed. That means on-site control to tweak a given mix as needed, as well as to mix and place different types of concrete from the same truck at the same site, or adjacent sites.
By adding the minimal amount of water as the mix is being prepared, volumetric mobile mixers produce fresh concrete at the job site that’s 5 to 10 percent stronger compared to concrete from a batch plant that’s mixed there and transported to the job as it begins to cure. There’s no need to worry about over-curing, there’s no waste, and the crew knows exactly when to start their finishing work after the pour is complete.
Eliminating the need to get concrete on the ground quickly reduces stress for everyone involved. If the job requires or benefits from a mix, pour, and wait approach, it’s simple to do that. For example, several applications like road repairs produce a better finished product when the crew can take its time. With an initial pour to stabilize things, some time to let that begin to set up, and then a final top cover to finish the job, the waiting that makes for a better road is time that a ready-mix truck driver doesn’t have. That’s when everyone is anxiously waiting, nervous knowing the concrete in the truck’s barrel is over curing.
Eliminating variables out of your control and gaining control over more of the critical variables involved in mixing and placing a concrete batch reduces stress on everyone involved. It also gives much more flexibility with timing. Need the product a little sooner or a bit later? No problem. Just let the company dispatcher or driver know and everyone can adjust accordingly.
Need to pour super early, or after hours, or even on the weekend? A self-contained volumetric mixer truck can operate at any hour or day, in almost any location. There’s no need to restrict delivery of concrete to only the days and times the ready-mix plant is up and running and able to load traditional cement trucks.
Ready to Join the Volumetric Mixer Movement?
If you’re ready to start enjoying the benefits of volumetric concrete mixing on site, and complete monitoring and control of the concrete curing process, contact us today.
Our partnership with you begins with the careful selection from Holcombe’s lineup of volumetric concrete mixers. Ours have more standard features than any other mobile concrete mixer. Our patented removable conveyor system allows belt changes in as little as five hours. But our mixers are much more than their technology. We are personally invested in ensuring your team has the essential training and the vital resources to scale your business with your Holcombe volumetric concrete mixer.