New Applications for Polymer Overlays

Abstract

Polymer concrete (PC) overlays have proven to be a very effective method of extending the lives of bridge decks and improving skid resistance. Many states in the U.S have specifications and have used overlays on hundreds of bridge decks. Multiple-layer epoxy, epoxy and methacrylate slurry, and polyester premixed overlays have been widely used. One of the keys to successful performance is surface preparation. The very light weight, water tightness, good skid resistance, excellent bond to concrete, and excellent durability have made PC overlays a very sustainable solution for increasing the life of bridges and parking garages, But in recent years very thin overlays referred to as high-friction surface treatments (HFST) have been widely used to provide skid resistance for asphalt pavements in high accident zones, particularly on horizontal curves. Several state departments of transportation (DOTs) have reported very significant reductions in accidents after HFST have been applied. The total length of the application is often only a few hundred meters or less. The cost, when compared to other remedial measures, has been very competitive. The treatments are very similar to very thin slurry overlays. The purpose is not to structurally rehabilitate the pavement, but to provide increased skid resistance for safety. There is also an increased use of thin overlays to provide color for applications including pedestrian and bicycle lanes, bus lanes, entrance and exit ramps, cross walks, and rail road crossings. There are few standards in the U.S. for colors in various applications or for where color should be used. But these thin overlays provide high visibility, skid resistance, and long life. A discussion of these applications, materials and installation methods, and where available, costs, will be presented.