Continued Performance and Economic Issues for the Polk County Minnesota Bituminous County Road Constructed With Municipal Solid Waste Combustor Ash Available to Purchase

This paper is a follow up to previous installments presenting environmental, construction, performance and economic issues associated with Polk County CSAH 13. The CSAH 13 project was a demonstration of the use of municipal waste combustor (MWC) ash in bituminous. New structural and cost data is presented. The incorporation of MWC ash into bituminous pavements has been investigated in the United States since the middle 1970s. Thus far, most, if not all of these projects, have attempted to answer the questions: Is it safe? Is it feasible? Or does it provide an acceptable product? The presented project answers these questions on a new level. MWC ash amended bituminous was used to construct a portion of 2.25 miles of road in Northwest Minnesota. Significant environmental and structural testing was performed prior to, during and after construction. Environmental testing on this project has shown that the use of MWC ash in bituminous pavement, as performed, is safe. In addition, economic analysis shows important financial advantages by using ash-amended bituminous. Structural testing showed a 36% increase in stability, 19% increase in flow and a 17% increase in spring season axle load capacity. Improvement in resistance to freeze-thaw cracking was also shown.