Angel Lane is a low-volume, two-lane, asphalt roadway that has served as the “back entrance” to Columbia Regional Airport for many years. Detours from roadway construction on US Route 63, which runs west of the airport property, resulted in increased traffic using Angel Lane to gain access to the airport, and for heavily loaded vehicles associated with the construction activity. The increased volume over several years contributed to poor pavement conditions. ES&S was engaged by the City of Ashland to perform a subsurface investigation and make recommendations for pavement rehabilitation or replacement. Results of the study showed substantial failure of the subgrade material along this 1.25-mile paved road. For this reason, a mere resurfacing was not recommended, especially since the City owns property along the corridor, with hopes of developing an industrial park in the future.
Funding challenges for a major reconstruction of the pavement caused a search for innovative alternatives. The City worked in partnership with Boone County to fund this project. The County had recently reconstructed a roadway in north Columbia using Full Depth Reclamation (FDR). The FDR construction process mills and recycles the existing pavement and sub-base materials of a roadway. With the addition of cement, the recycled material is mixed, shaped and compacted to create a more stable material that can then be used as a base for a roadway surface course. FDR can be a cost-effective means of providing a higher quality pavement for lower-volume roadways than traditional reconstruction or mere resurfacing.
For the Angel Lane project, the use of FDR for the full length of the roadway resulted in a cost-savings of over 35-percent compared to an option with full-depth PCC pavement for approximately one-third of the length. ES&S facilitated a “Lunch & Learn” for public works officials in the region to observe the FDR process.