Review on evolution and evaluation of asphalt pavement structures and materials

The purpose of this study was to summarize the wide-range literatures on asphalt pavements, explore the evolution of road pavements, analyze typical asphalt pavement structures, highlight current trends in research and industry, and to recommend future areas of research and development. In this research, road pavement evolution was explored from the earliest roads to the modern pavements. A new method was recommended to categorize asphalt pavement materials into the three large families which may be further sub-divided according to their mechanical parameters. A unified asphalt pavement classification (UAPC) method was proposed and the worldwide asphalt pavements could be divided into six types through the new method. Based o n the UAPC method, 1087 asphalt pavement structures were classified and analyzed to explore the asphalt thickness variation. In order to evaluate asphalt pavement performance, the Chinese design specification was employed for analyzing lives of 29 high-volume pavements and 28 low-volume pavements. Through this research, it was found that: (1) in the past 100 years, asphalt pavement materials and structures had been becoming more and more strong; (2) asphalt layer thicknesses were various from 5 to 60 cm and the overall pavement thicknesses were various from 28 to 160 cm; (3) the long-life pavements in the other countries may become "shorter-life" pavements according to the prediction based on the Chinese specification.