National Concrete Pavement Technology Center

About the research

Different pavement preservation treatments have been used by local public agencies to enhance the quality of pavement condition and extend pavement service life. Micro-surfacing is one of the common pavement preservation treatments that is used. Micro-surfacing is a cold-laid, polymer-modified asphalt mix containing crushed aggregate, asphalt emulsion, water, polymer additives, and mineral filler to fill ruts and improve surface friction. It can be used as a leveling course or a surface course for existing pavements. Micro-surfacing has been found to be effective in slowing raveling and oxidation, sealing cracks, enhancing skid resistance,and generally improving the longevity of a pavement structure. Chip seal is also widely used as an effective, low‐cost preventative maintenance treatment for low‐volume roads across Ohio and around the country. Over the past four decades,there has been growing interest to increase the amounts of Reclaimed Asphalt Pavement (RAP) in construction of pavement structures. The use of RAP not only reduces the construction cost, but also conserves non-renewable natural resources, such as the aggregates and bitumen. RAP has been successfully used in new asphalt mixes, but it has not been utilized in micro-surfacing or chip sealing mixes. Some studies showed that it is possible to prepare micro-surfacing mixes with 100% RAP while meeting all performance specifications; however, these results were not validated in the field. Research is needed to evaluate the effects of using RAP on the properties and the performance of micro-surfacing and chip sealing mixtures that are typically used on local roadways.

The goal of this research is to develop a method to design cost-effective, well-performing, and durable micro-surfacing or chip sealing mixtures with various RAP contents to be used on local roadways in Ohio.The objectives are to assess the availability and feasibility of using RAP for these types of applications and develop field evaluations to test the proposed applications.