Full Depth Reclamation helps bring apron back to life
Neel-Schaffer provided engineering design, construction administration and testing services for this $735,000 project to reconstruct the apron at the Lawrenceburg-Lawrence County Airport.
The 8,400-square-yard apron was built in 1960 and then expanded in 1984. It had only received a few seal coats and crack seal treatments during its life cycle, and was therefore extensively block cracked full depth and in need of reconstruction.
Neel-Schaffer determined Full Depth Reclamation (FDR) was the most economical form of reconstruction for this project during the preliminary engineering phase. FDR is the process of pulverizing the existing asphalt and crushed stone base course, blending with cement and water, and then grading and compacting to serve as the new pavement’s base course.
The benefit is cost savings for not having to demolish and remove the pavement and base material, and not having to import new and expensive materials aside from cement and the new asphalt surface course. Essentially, you make use of what is already there, which is an economical and common sense approach. The FDR process is also faster than traditional reconstruction which further reduces construction costs. The apron was scheduled for a 30-day closure, but was able to be reopened to air operations in three weeks. The project was funded with a $1 million FAA AIP State Apportionment Grant through Tennessee Department of Transportation Aeronautics, but the total construction cost ended up being 20 percent under budget.
We were able to lower a portion of the apron to reduce flooding potential that was a problem for the maintenance hangar, and we were able to work around several site constraints, including the fuel farm, connector taxiways, and two hangar buildings. We also performed a detailed analysis of the “Direct Access” issue (from the apron to the runway) prior to bidding, in order to convince TDOT not to require the taxiway serving the apron to be reconfigured within the project. We successfully postponed this work for a project in the future.