In 2008, Pierce County in Nebraska planned to a paving project as an asphalt overlay. However, due to escalating asphalt prices, they rejected all bids and abandoned that plan. The designer suggested to the Pierce County Board that an unbonded concrete overlay could be placed for nearly the same initial costs and actually save money if life cycle costs were considered. The designer made some preliminary cost estimates and discussed the benefits of the overlay with the Board at a number of public meetings.
The project was bid as a pavement overlay of four inches of asphalt or six inches concrete. After reviewing the bids, the County found that the initial cost of concrete was actually cheaper than that of asphalt if the same pavement thickness was compared. The County Board awarded the project as a 6-inch by 220-foot wide unbounded concrete overlay over existing asphalt pavement in spite of the fact that few examples of this type of construction existed in Nebraska. The County was impressed with the final results.
No special materials or equipment were needed to complete the construction. The existing asphalt pavement was cleaned, minor repairs were made and the pavement was placed using a slip form paving machine. Closure to traffic and placement of pavement hubs were the only additional requirements necessary when compared to an asphalt paving project. The project was phased in two pours in order to provide property owner(s) access to their homes. A ribbon cutting was held at the end of April with the County Board and design firm, JEO Consulting Group, in attendance.