State Aid Project (SAP) 43-603-032, McLeod County, MN
Contractor: PCI Roads
Owner/Engineer: McLeod County Public Works
When an existing bituminous roadway needed to be rehabilitated, the McLeod County Public Works department decided on a concrete overlay to provide a long lasting, durable, pavement that not have the future road-user delays associated with traditional bituminous maintenance. The concrete overlay is also expected to provide better fuel economy than a bituminous solution, thereby lowering the road’s carbon footprint.
State Aid Project (SAP) 043-603-032 was a 6.4 mi. concrete overlay on County State Aid Highway (CSAH) 3 in McLeod County, which is located approximately 60 miles west of the Twin Cities. CSAH 3 is a major collector and serves as a primary connection between the City of Glencoe and Trunk Highway 15 to the west, serving many farm-to-market haulers.
The existing bituminous roadway was 24 ft. wide and had 8 ft. aggregate shoulders with several horizontal curves. The project consisted of milling the existing asphalt pavement to a designed profile and cross slope to improve the ride as well as correct deficient super elevation transitions associated with the existing horizontal curves.
The concrete section consisted of 6 in. of undoweled, plain concrete that was jointed in 6 ft by 6 ft panels with a tied shoulder, all of which was placed in a single 32-foot wide operation.
Some of the bituminous millings taken from this project were used for part of the shoulders, while the remaining materials were stockpiled and will be used on future County projects, thereby avoiding minimizing the use of virgin materials.
The concrete mixture called for a low water/cement ratio to impart durability. The owner also specified 100% class A (granite) coarse aggregate.
The contractor encountered some random areas where the old transverse cracks in the bituminous pavement were very deep, but to address the problem, the areas were monitored closely, and filled with washed sand to prevent formation of paving lugs and to keep the concrete quantities in line.
CSAH 3 was closed to all through-traffic during construction, but the contractor provided access to residents and businesses along the project route during portions of the project.
In advance of the project, McLeod County Highway Department sent letters to all property owners in the area two months prior to the project. The letters detailed the project schedule and traffic concerns and included contact information for owners wanting more information. Agricultural businesses that were in operation and potentially affected during the construction phase were also contacted, and in addition to the outreach by the highway department, the contractor also communicated with owners prior to paving to help determine how and when they would leave and re-enter their property.
A press release was also used to inform the general public of the project which included details about the road closure and project schedule, and this effort was also augmented with social media posts.
As a result of the expert project management and execution, along with the effective communications, PCI finished the project on time, leaving property owners and travelers with a durable roadway that will handle vehicle traffic of all types for many years.