For the Love of Skidsteers
When I first saw a concrete bucket mixer attachment for a skidsteer, and learned that it was used to mix and maneuver hempcrete, I was a bit dubious. After watching one operate on a hempcrete construction site, I’m now convinced that it’s a great tool. Ideally it is used to mix and to help place hempcrete in the building precisely and efficiently.
HempStone had the opportunity to gain experience with this equipment this spring for the 1st hempcrete house in Massachusetts. Shelby Howland, owner of Village Carpentry and Landscaping, immediately saw the potential for this equipment for his first hempcrete build. Shelby already owned a skidsteer, so adding a concrete mixer to his repertoire was not a significant investment. For a few thousand dollars, he found this 10.5 cu.ft. mixer, and with a little augmentation, it is easily able to handle 2 batches of hempcrete at a time.
This mixer serves as a robust system for mixing and distribution of hempcrete.
First, the ingredients are mixed together in the following order: 1) hemp, 2) lime-binder, 3) water. Mixing after each component is added offers several bonus opportunities. By placing the hemp hurd in first, the hurd can be mixed by itself to break up any clumps. Once this is done, the mixing speed can be increased to expel any dust from the hurd. Next, the lime-binder is added. Shelby’s building used both a natural hydraulic cement and a local hydrated lime. Each was placed into the mixer - one type of lime on top of the next. Then, the mixer was rotated slowly. This allowed the lime binders to fold together. Once this occurred, the mixer speed was increased to then evenly coat the hemp hurd. Finally, water is added and the material was mixed to create a consistent wet hempcrete mix. Once the water is added, the hydraulic set begins, and time is of the essence.
Here again, the mixer on a skidsteer is advantageous. As a small piece of wheeled equipment, it is compact enough to move easily around the site. The skidsteer can position itself exactly where the mix is needed along the wall, and moves easily with the crew as they place hempcrete into forms along the perimeter of the building. Fully extended, the skidsteer can deliver a full load of hempcrete to the second story with ease. The bucket can be emptied in short order. While the hempcrete is being placed into the wall by the crew, the skidsteer operator can prepare another hempcrete batch.
As with any construction site, using powerful equipment requires a skilled operator and an aware and attentive crew to maintain safety on the job site. Paying attention and having good communication are simple yet effective ways to keep everyone safe while installing hempcrete efficiently and effectively. Fortunately, this is relatively easy to do since the skidsteer operation is relatively quiet. A crew can carry on conversations at normal volume during operation, and issues can be communicated easily.
All in all, this equipment is great for projects that have access to a skidsteer. Being a mobile mixing and efficient delivery method means that the crew can focus on doing what’s most important - getting the right amount of material into the building at exactly the right time. What’s not to love?