Description
This work presents a research program that aims at evaluating the performance of hot asphalt mix used in highway pavement rehabilitation with the addition of recycled rubber of tires. The objective of this study is to quantify the performance of asphalt mix when recycled rubber is added. This study will be based upon field tests to evaluate whether a relatively thin overlay with Asphalt Rubber (AR) could reduce reflective cracking. In 2001, the private agency Univias designed and carried out a large scale AR test project in Rio Grande do Sul, Brazil on the very heavily trafficked Interstate BR116. AR is a mixture of 88% hot paving grade asphalt and 12% ground tire rubber. This mixture is also commonly referred to as the asphalt rubber wet process. The overlay project was built on top of a very badly cracked concrete asphalt pavement. The performance of the asphalt rubber overlay surpassed the original expectation. This paper presents a brief history of asphalt rubber use and comparative results to evaluate the performance for hot-mix structural overlays, containing conventional or polymer-modified binders with similar applications containing asphalt rubber binder. After two years of service the overlay is still virtually crack free, with good ride, virtually no rutting or maintenance and good skid resistance. The findings indicate that asphalt rubber is cost effective.
