Materials Evaluation and Mix Design Procedures for Cold In-Place Recycling of Asphalt Pavements

Project summary:

Increasing pavement construction costs, scarcity of quality paving materials, energy and environmental concerns, and the need to preserve roadway geometries have focused interest on asphalt pavement recycling. Cold and hot asphalt recycling generally involve transporting material to a central plant where it is processed, returned to a construction site, and recompacted. Cold in place recycling (CIR) has the advantage of eliminating the need to transport recycled material to a central plant A train of equipment is used to mill, crush, screen, rejuvenate, and recompact the old pavement in place. In CIR, all or part of the asphalt layer is milled, rejuvenated, and recompacted to form an asphalt base layer. The purpose of this research is to evaluate the variety of Minnesota recycled asphalt pavement (RAP) sources and to develop a mix design procedure for Minnesota. Samples of RAP from each of Minnesota's eight districts will be sampled and tested. Samples will be blended with an asphalt emulsion, compacted in the gyratory compactor, and tested for stiffness, strength, and moisture sensitivity. This study is expected produce a CIR mix design for Minnesota.