Model Calibrations with Local APT Data and Implementation for Focused Solutions to NAFTA (9-1502-01-S)

This project summary report summarizes the research performed in Texas Department of Transportation (TxDOT) Project 9-1502-01. The goal of this six-year project was to create defensible systems to predict the additional pavement damage and economic impacts of Mexican and Canadian loads on U.S. roads. The VESYS5 pavement distress prediction model can be calibrated with local materials and performance data. This latest version of the program includes the capability to handle both tandem and tridem-axles and predict rutting within each pavement layer. The objective of this project was to integrate the accelerated pavement test technologies of Texas, Louisiana, and other participating states with VESYS5 developed by the Federal Highway Administration (FHWA). Researchers evaluated existing laboratory test procedures for characterizing rutting resistance using cores with variable rut depth. Researchers also developed a procedure to calibrate the performance model using accelerated pavement test (APT) data. Researchers upgraded VESYS5, originally a DOS program, to a more user-friendly Windows-based program: TTI VESYS5W. Researchers found that TTI VESYS5W provides a user-friendly input and visualized output interface and significantly improves the usability of the existing VESYS5 program. One of the special features of the TTI VESYS5W program is that the default values of material properties have been built into the program. Significant progress has been made in both laboratory characterization of pavement materials and associated pavement performance prediction under this project.