A process that recycles old asphalt into new road base was recently used on 7800 South in West Jordan.
Full Depth Reclamation has been used by UDOT for about five years. The process uses a large piece of equipment called a reclaimer to grind up and re-use the old road instead of removing old road material and hauling it off.
Here’s a simple step by step:
First, a few inches of asphalt is milled off the old road. The area is pulverized and water is added, if needed. The reclaimer passes over the road and grinds up the pulverized portion, then passes again and adds an emulsion.
At this point, the material is slightly oily and looks like Oreo cookie crumbs. A sheep’s foot roller and a grader are used to compact and grade the soon-to-be road base.
The new base material is then rolled to the correct compaction. With evaporation, the compacted area gets harder and becomes suitable as new road base. On 7800 South asphalt pavement tops off the process.
Lonnie Marchant, Materials Engineer at UDOT Region Two is a champion of FDR because the process:
Makes good economic sense. It’s a good use of increasingly scarce resources to recycle road material if possible.
Produces a good base. Structural numbers for FDR are almost as good as new asphalt.
Reduces wear on surrounding haul routes. UDOT has observed wear and tear on roads near other projects sites after heavy trucks haul away materials.
Reduces impact to road users and property owners along the construction corridor. FDR is great for an urban setting because the process is fast and requires fewer large trucks that slow traffic. Vehicles can drive over the crushed material right away, so driveways are only blocked while the equipment passes.
FDR has been used on three Region Two projects with very good results. UDOT will continue to use FDR and other processes that save money and make good use of used road products.