Development of transfer function for crack area prediction in asphaltic pavements by fatigue damage simulation using S-VECD model and elastic analysis

Abstract

The evolution of materials characterization methods and of the amount of materials tested nationwide in the past decades made it possible to organize a road pavements database. These are essential information for pavement design with transfer functions that allow performance prediction from computational modeling. The main objective of this work is to develop a transfer function associating laboratory fatigue damage characterization data to surface cracked area observed in field. The tools used were the asphalt stiffness, characterized by the complex modulus, and the fatigue life, characterized by the integrity curve (C vs S) and the failure envelope (GR vs Nf), and associated with multilayer elastic analysis and a reduced damage variable. Calculated damage evolution results were used to predict field observations of percent cracked areas. In a calibration phase using 27 test sections, it was possible to obtain a unique transfer function between laboratory predictions (in terms of calculated damage) and field observations (in Terms of percent cracked area). The validation of the transfer function was performed with 17 other sections. Through 2 pavement design examples, it was observed an important aspect of the conventional definition of the average reduced damage variable, especially in the prediction of pavements with surface course greater then 15cm.