Implementation of Texas Mechanistic-Empirical Flexible Pavement Design System (TxME)

The Texas Mechanistic-Empirical flexible pavement design system (TxME) allows Texas pavement designers to take full advantage of new or premium materials, with a full consideration of the influential factors including pavement structure, traffic volume, and environmental condition. To further enhance and implement the software, extensive lab testing was conducted to develop default material properties. These properties include the default dynamic modulus, rutting and cracking properties of asphalt concrete (AC) mixtures, and moduli of other layer materials. Specifically, the relationships between reclaimed asphalt pavement/reclaimed asphalt shingles contents and the AC material properties were established and incorporated into the TxME. In addition, default load spectra and initial construction cost analysis were integrated into the TxME. All these features greatly enhanced the practicality and ease of using TxME when conducting pavement design. The Texas Flexible Pavement Database was used to calibrate the TxME performance models. The calibrated TxME was then employed to predict performance of 11 identified test sections located in six different districts. The comparison between the TxME predictions and the field performance survey results further confirmed the validation of the calibrated performance models. Overall, the current TxME is practical, user-friendly, and ready for statewide implementation.