Guidance to designing and constructing long-life composite pavement systems that provide durable, sustainable aggregate surfaces at a potentially lower cost than conventional pavement.
New Composite Pavement Systems (R21)
Challenge
Many agencies today are faced with the challenge of being sustainable (that is, using recycled materials) and economical in rehabilitating pavements, while also providing for a long service life. A few agencies today also face the challenge of having a limited source of quality aggregates, thus having the added cost of importing materials. Pavements that combine new asphalt over concrete, and/or 2 lift concrete generally have a long service life with excellent surface characteristics, structural capacity, and the ability to be rapidly renewed. However, the majority of roads containing these composite pavements resulted from maintenance and rehabilitation activities. Few roads are intentionally designed to utilize composite pavements because reliable guidance for designing and using these materials has been lacking. U.S. Transportation agencies require guidance, specifications, objective and reliable performance data, and life-cycle cost analyses to support use of these pavement systems.
Solution
SHRP2’s Composite Pavements Solution provides detailed performance data on existing composite pavement systems, and offers step-by-step guidance on two types of composite pavements (Hot-Mix Asphalt (HMA) over Portland Cement Concrete (PCC) and PCC over PCC [constructed wet on wet]) using procedures consistent with the Mechanistic-Empirical Pavement Design Guide (MEPDG).
Benefits
With the new guidance, models, techniques, and specifications, State and local departments of transportation and other organizations can have confidence that the new composite pavement systems they install and maintain will be long lasting and have predictably low life cycle costs. Agencies will no longer need to develop construction specifications and quality management guidelines on their own, but instead, can consider using these guidelines. The training tools and case studies include relevant design and construction issues, and are essential to widespread adoption and use of composite pavements.