Long-Life Composite Pavement Systems
The Strategic Highway Research Program 2 (SHRP 2) R21 project on Composite Pavement Systems is under the Renewal area of SHRP 2, the goal of which is to develop a consistent, systematic approach to performing highway renewal that is rapid, causes minimum disruption, and produces long-lived facilities. Two composite pavement design strategies were determined to
reflect the SHRP 2 Renewal philosophy of “get in, get out, stay out”:
- High-quality, thin, hot-mixed asphalt (HMA) surfacing (e.g., dense HMA, stone matrix asphalt, porous HMA, asphalt rubber friction course (e.g., Nova Chip)) over a new, less expensive, portland cement concrete (PCC) structural layer (e.g., jointed plain concrete (JPCP)), continuous reinforced concrete pavement (CRCP), and jointed roller-compacted concrete.
- High-quality, thin, PCC surfacing (e.g., exposed aggregate concrete, diamond grinding, conventional texturing) atop a thicker, less expensive structural PCC layer (e.g., JPCP, CRCP).
Both types of composite pavements have strong technical, sustainable, and economic merits in fulfilling the key goals of the SHRP 2 program including long lived pavements, rapid renewal, and sustainable pavements. These merits exist because the upper surface requires higher durability materials (which cost more) than the lower PCC portion, which does not require the same quality (or cost). This research investigated the design and construction of new composite pavement systems for all levels of highway and urban streets. The behavior, material properties, and performance for each type of composite pavement under varying climate and traffic conditions were determined. The AASHTO MEPDG and other structural, climatic, material, performance prediction models, and design algorithms were evaluated, and some were improved as needed. Practical recommendations for construction specifications and techniques, life cycle costing, and training materials were prepared.
Presented at FHWA’s International Conference on Long-Life Concrete Pavements in 2012.
Authors: Michael I. Darter, Shree Rao, Lev Khazanovich, Derek Tompkins, John Harvey, James Signore, and Julie Vandenbossche