Advancing the design and construction quality control of flexible pavements

Abstract

The paper presents several advanced features that can be used in the process of pavement design and construction quality control. The models for predicting the pavement performance in the latest version of mechanistic empirical pavement design guide form the basis of the proposed system. In order to add the new features, it was necessary to make simplifications concerning the moisture distribution in the unbound materials and the ageing/oxidation of the upper asphalt concrete (AC) layers. The add-ins to the program include: (1) An analytical reliability analysis where the variability of the performance prediction components is computed from the variability of the pavement parameters; (2) An improved simulation of the temperature distribution in the AC layers during the design period; (3) An option for adding an overlay during the design period, to simulate maintenance or stage construction and (4) The possibility to use a 2D finite element analysis with nonlinear and cross-anisotropic materials, in addition to the well-established linear elastic analysis. The proposed system runs every hour of the design period and computes the fatigue bottom-up cracking, rutting in all pavement layers and international roughness index. It runs very fast, less than one minute in the linear analysis and less than 30 min in the nonlinear case. Few cases are presented to illustrate the benefits of the above add-ins.

Keywords:

• Flexible pavement performance
• analytical reliability
• nonlinear unbound material
• overlay
• stage construction