Development of an Economical Thin, Quiet, Long-Lasting, High Friction Surface Layer for Economical Use in Illinois, Volume 2: Field Construction, Field Testing, and Engineering Benefit Analysis

This project provides techniques to improve hot-mix asphalt (HMA) overlays specifically through the use of special additives and innovative surfacing technologies with aggregates that are locally available in Illinois. The ultimate goal is to improve pavement performance through optimized materials while also controlling cost by efficiently using local materials. Therefore, the proposed new mixes use locally available aggregates when possible. The project also considered the use of alternative aggregates such as steel slag to increase the friction quality of the HMA and therefore improve pavement performance. To evaluate the newly developed wearing course mixtures and evaluate their performance under actual traffic loading, test pavements were constructed, including control mixtures, between August and November 2010 in northern Illinois. The newly proposed mixtures include fine dense-graded HMA and stone matrix asphalt (SMA). The fine dense-graded HMA was designed using the Bailey method and developed with the hope of improved compactability for thinner asphalt layers. The SMA contained a 4.75-mm nominal maximum aggregate size (NMAS) that allows for layers as thin as 0.75 in. On-site performance tests were conducted at 4-month intervals following construction; the tests include noise, friction, rutting, and texture profiling. An engineering benefit analysis was performed to evaluate the new mixes’ cost effectiveness. New HMAs are proposed, along with alternative cross-sections that improve pavement performance while controlling costs.