Precious Recycling of Reclaimed Asphalt as Hot Mix Asphalt by Use of Rejuvenator

Abstract

Asphalt is one of the most frequent and effective recyclable construction materials. The recycling of reclaimed asphalt (RAP) makes both environmental and economical, sense. In this study, asphalt mixes with four different recycling agents (rejuvenators) in different content were produced and tested in the laboratory of the TPA in Cologne. A great number of tests on asphalt mixes and extracted binders were carried out to produce a green asphalt mix with similar or better performance than asphalt mixes prepared with virgin material. The viscosity of the resulting bitumen was effectively decreased with the increase in recycling agent content. Due to that, the mixing and compaction temperature of asphalt mix with RAP could be decreased from 170 to 140 °C. By means of optimierung the contents of recycling agents, asphalt mixes with RAP content can be produced in any quality comparable to the asphalt mixes prepared with virgin bitumen and aggregates. Finally, asphalt base course mixes as warm mix asphalt with a RAP content of 40% in combination with four-selected rejuvenator were produced at asphalt mix plant and constructed in test fields. The determined test results of asphalt mixes produced at asphalt mix plant confirm the test results determined on samples produced in the laboratory. In addition, the determined test results show also that the mechanical and performance properties of resulting bitumen of asphalt mix with RAP content cannot be described by means of a single test method and several test methods are necessary. But, the respective characteristics on low, medium and high temperatures can be determined by means of adequate test methods according to well known European Standards EN 12697.