A vibratory roller attachment can be used for patch work and compaction of base material.
Contractors can use a wheel saw attachment to cut through asphalt to produce a vertical edge for repairing pavement and improving the joint bond between new and existing layers of asphalt.
By Christina Schave, Public Relations, Des Moines, Iowa
The usefulness of skid-steer loader attachments has helped make the machine one of the most popular tools on asphalt and paving jobs. Every paving contractor has a planer for creating edges in transverse joints and removing pavement. Hydraulic breakers are typically used to bust up concrete or asphalt, and sweepers do a great job of cleaning up after milling work is complete.
It's the less common skid steer attachments a paving contractor should have, but might not have considered - such as the vibratory roller, grader, and wheel saw - that can aid in even more efficient project completion.
Vibratory Rollers to the Rescue
This high-performance, hard-packing attachment can be used for two different jobs: patch work and compaction of base material.
A vibratory roller allows you to compact asphalt patching jobs while moving forward or in reverse. "A vibratory roller's wide drum would do a better job of packing down asphalt in a pothole without leaving a sinkhole-like spot in the middle," says Justin Odegaard, Bobcat product attachment specialist.
A vibratory drum roller, as opposed to a static drum roller, will give the greatest compaction density because the vibrating action of the roller will allow the base material to realign and compact from the bottom up.
For the compaction of base material, the smooth drum style of vibratory rollers is used in most flatwork applications and works best on material such as gravel, pea rock and sand. The offset drum design allows the contractor to compact next to sidewalks, walls or curbs, while the oscillation keeps the roller in contact with the surface on uneven terrain.
For the most consistent compaction through the subbase material, Bobcat recommends 6-in. lifts or less. For example, if 12 in. of material needs to be compacted into an area, complete it in two stages, or 6 in. at a time. This will provide consistent compaction to the subbase material and allow it to carry more load.
Make at least two or three compaction passes over the entire work area. Testing has shown the second pass will significantly improve the overall compaction rate.
Finally, drive the loader slowly when compacting. A slow, steady travel speed allows the vibratory action to fully penetrate the soil, giving good compaction levels at full depth.
Smoothing Things Out with Graders
Many contractors have a loader in their fleet, but a grader attachment negates the need to have a dedicated grader onsite. This results in a lower initial cost and less storage space required.
"Asphalt contractors have used graders for years to accomplish their grading work. Their long wheelbase minimizes elevation changes of the surface requiring less operator input than would be required with a bucket or dozer," Odegaard says. The grader attachment uses the same concept by placing the front wheels well ahead of the moldboard. This leaves an even surface that makes it easier to put the asphalt down and get nice, smooth results.
Independent adjustment of either side of the moldboard makes it easy to add crown to a flat area. Angling the blade will move material to the side so the machine/attachment can grade, windrow the material to the side and continue to work their way across a jobsite.
"If paving large, flat areas or flat roads with a crown, laser receivers can be hung on the attachment in just a few minutes and dramatically increase grade accuracy while reducing operator input and the time it takes to get the job completed," Odegaard explains.
Wheel Saws Can Cut it Out
This under-used skid-steer loader attachment enables operators to cut through asphalt and concrete to produce a vertical edge for repairing pavement and improves the joint bond between new and existing layers of asphalt or concrete.
With trenching depths of 6 to 24 in. depending on the model, these rugged attachments are used for asphalt/road repair and for installing water, gas, electric, and fiber-optic cables without the mess of excavation using backhoes or excavators.
"A wheel saw is basically the same idea as a planer, but you can use it to cut joints or specific sections of asphalt to lay utilities across a road, instead of bringing in a large directional drilling unit," Odegaard says.
The trench cleaner, which is raised and lowered hydraulically, ensures a clean trench. The wheel saw provides a more precise cut than air or hydraulic hammers and, along with the other attachments mentioned here, is easier to transport than dedicated machines.
This article was provided by the Bobcat Company, Fargo, N.D.