The Kansas Department of Transportation uses multi-coat polymer concrete overlays for bridge preservation. The first multi-coat polymer concrete overlay was placed in 1999. To this point in time the Kansas Department ofTransportation (KDOT) has placed over 90 polymer overlays all with the intent of protecting structures that are not seriously deteriorated minimizing chloride and water intrusion to preserve the structures while still very serviceable. Typically candidate structures have had minimal spalling which is repaired and may have cracked delaminated silica fume or high density overlays with no failure of the surface itself. The average savings of using a polymer overlay over a silica fume overlay as a maintenance bridge preservation action is $16.00 per square yard. Significant savings arealso found in user costs and traffic control costs. Most of the structures that the polymer overlays have been placed on in Kansas are relatively short, 200 to 400 feet. However, two structures (Bridges 290 and 291) in Sedgwick County 12,496 and 12,110 feet long with approximately 44,800 vehicles per day in each direction with approximately 7 percent trucks, were overlaid in 2007 and 2008. The Kansas experience in general has been very good; however, it has not been without some problems and a learning curve. Additional wording has been added to the Kansas Standard Specification to provide additional attention to eliminating potential problematic issues. The Kansas Department of Transportation is planning on the continued useof the Multi-Coat Polymer Concrete Overlay for preservation purposes and on new bridge structures.
Samenvatting