Estimation of Relative Performance of Overlaid Asphalt Concretes against Reflection Cracking due to Shear and Bending Fracture Mode

摘要

Most of overlaid asphalt pavements are facing reflection cracking in an early age of service life. To retard progression of the reflection cracking, many materials and techniques have been utilized to the overlay pavement by many researchers. In this study, an interlayer at the interface between old concrete pavement surface and overlaid asphalt mixture, and polymer modifiers were used as an effort of retarding crack initiation and for strengthening mixture, respectively. An expedited reflection cracking test method was developed and applied to various mixture specimens. The results were compared to one another with respect to the resistance characteristics of reflection cracking. Theoretical prediction model for fatigue life against reflection cracking was developed to compare relative performance of the material choices based on experimental test result. Most of the models showed a very high coefficient of determination (r~2 = 0.95 or higher). Therefore, fatigue life of each specimen can be estimated well with the prediction models developed in this study. These models can be used to select a best performing material combination by comparing many alternatives relatively for overlay of old concrete pavements at a selected field.