Asphalt pavement performance : Structural design, SHRP and LTPP

The SHRP research program is the largest of its size since the AASHO road test in 1959. Although the asphalt pavement section of the SHRP program dealt mainly with performance based mixture design and binder classification, the SHRP conclusions and the SUPERPAVE system will affect the development of improved design methods for the prediction of pavement structure performance. Included as part of the SHRP project is the SHRP-LTPP program, which is a 20 year project that monitors North American in situ sites for the validation of the SHRP research. Additional large test track research is being performed in the US states of Minnesota and Nevada. Some planned projects include a RILEM-LTPP project for evaluating performance prediction methods and a Swiss-LTPP project for collecting regional climatic and pavement data. These projects are recommended as they will assist in bringing about the restructuring of design parameters and assumptions for a more performance oriented and cost optimized approach. Included with LTPP testing, work should begin on adapting and validating a structural design system to utilize new and alternative materials, new loading configurations, new structural concepts, and new testing systems while continuing support for existing materials and concepts.