McQuay Construction: Concrete Paving With Volumetric Mixers
Going into a project like this took a lot of preparation to ensure the process and results are efficient and satisfactory. We have to take into account this project is 700 acres and will have 265 home sites when finished. With 8 miles of concrete, we are building all the roads and all the utilities. We have built or will build all the home pads. We will do the water line, electric line, road paving, tree removing and obviously the paving. This takes planning and weighing our options for what will create the best outcome possible. In this article, we discuss our options, working with a paver, our fleet process, concrete consistency, and the volumetric technology used in this project.
Weighing Our Options
Concrete Vs. Asphalt
There are two options when it comes to paving, asphalt and concrete. Most think the typical answer is asphalt, that’s when concrete comes into the picture. We are able to get our numbers down on the concrete, really close to being comparable with asphalt numbers. The big instance for us is that there is not an asphalt plant close to us. We are able to make a mobile yard here and bring in our volumetric trucks. This allows for high production right here on the grounds. With asphalt they’re not able to do that efficiently here. We can efficiently run 350 yards a day on our paving, aiming for 1,000 yards in two days a week. For us, with our volumetric trucks, the obvious answer to this project production is concrete paving.
Volumetric Vs. Barrel Mixers
With our volumetric trucks our paver never has to stop. Our mud is consistent, and we can stockpile 30 to 40 feet in front of the paver so it doesn’t have to stop. We talked with a guy running a paver, who paves in Tulsa a lot as well, who works with ready mix trucks. The ready mix trucks are a bit faster dumping out, but they have to stop and when you have to stop you have to stop and start joints in your paving. Since he started here this morning the paver has not stopped moving since 9:30 AM. Overall, you get better quality of paving without having to stop with volumetric trucks.
Working With A Paver
We are working with a GOMACO paver on this project. They had never used a volumetric before this project for paving. Most guys use ready mix or dump trucks. Honestly, we didn’t know if this process would work or not. We talked about setting up and trying to pour into a dump truck, simply for volume to feed the paver. This road was our test project essentially to get it figured out where this process would work. With just one truck dumping at a time, we ran a relay with the trucks and so far it’s worked out really well. We have done about 3,000 feet of road so far and work to continue the process.
On this project we are running three mixers. We want one loading, one backing in and one at the paver at all times. When one gets out the other one will get in and go. Our goal is to never have the paver stop. On this project we brought our home base to the job site. It’s the same thing you do in your yard: just take it and bring it to your project. You need a way to load your powder here on site and a way to load your sand, rock and water. One guy loading the powder, one guy running a loader and a guy that helps manage the water. Essentially any volumetric operator or owner can do this.
Consistency Is Key
Our concrete is good and consistent every single time. We are running a 3500 psi mix with fiber. You can see the fiber coming down the rock and in the paving, the paving guys really love it. The consistency of the mud is creamy and gives us nice smooth edges, the finishers love it. In order to not run out of rebar in the road, we run fiber as a replacement. With a paving machine you can’t put rebar in efficiently because the trucks have to back onto it. We run just over a pound of fiber per yard. Each roll of fiber will get you roughly 40 yards. When the guys are loading the unit we have fiber up there for reload. It takes maybe a few minutes to reload the fiber. With fiber and good quality concrete you can do it with fiber and the structure is still good.
Lastly, the technology we use with our volumetric fleet is a major key to our success. ACCU-POUR™ helps us keep up with our yields to make sure our yield’s right. We build the roads ourselves, with ACCU-POUR™ I know how many yards 1,000 feet is supposed to be. With ACCU-POUR™ you can monitor your sand, rock, water and powder to ensure your mix design stays where it needs to be. I don’t know how you would do it without ACCU-POUR™. You’re able to see on a readout screen of where it is.