At Erickson Asphalt, we recently completed a project for Central Minnesota Diagnostic, Inc. (CMDI), a cooperative that provides advanced imaging technology services to hospitals across the region. CMDI’s parking lot had suffered severe rutting due to the heavy semis regularly accessing their facility. Addressing the issues caused by these large vehicles requires a specialized approach to ensure a durable and long-lasting solution.
We began by milling and removing 10 inches of the old, damaged asphalt, base and subbase material. This created a clean slate for us to work with. Since Milaca is known for its clay soil, we needed to take extra precautions to prevent future movement and cracking. We installed a geotextile fabric on top of the sub-base. This fabric plays a crucial role in reinforcing the pavement's foundation by preventing the clay soil from mixing with the aggregate base, which helps avoid instability and shifting. By keeping the base material intact and separated from the soil, the geotextile fabric helps reduce ground movement, minimizes cracking, and typically eliminates problems like alligator cracking that tend to occur in high-traffic areas.
With the old asphalt removed and the foundation stabilized, we built the new base layer. We utilized the asphalt millings we collected during the milling process and added 400 tons of class 7 aggregate. This created a strong base that will support the frequent heavy traffic CMDI experiences. The strong base ensured that the new asphalt surface would last, even under the constant weight of these vehicles.
Next, we laid down 650 tons of hot mix asphalt. We used a two-lift process, with each lift being two inches thick. Laying the asphalt in multiple lifts allows for better compaction, which is essential when working with heavy loads like semi-trucks. Using a hot-on-hot process creates a very strong monolithic layer, reducing the risk of cracking, rutting, or surface failure over time.
As an additional preventative measure, we installed an 8-inch apron to combat future rutting along garage bays.
We striped the parking lot once the asphalt was laid and fully compacted. We added fresh, clean lines to complete the project, ensuring the lot was functional and visually appealing. With these improvements, CMDI now has a durable parking lot that can handle the demands of its operation while maintaining a smooth, well-structured asphalt surface for years to come.
