Guide for the Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures Materials Characterization Is your Agency Ready?

Implementation of the first AASHTO Design Guide in the early 1960’s was a major paradigm shift in the pavement design process and required highway agencies to undertake several efforts over a period of many years to implement the new design procedures. These efforts included training of staff, analysis of truck axle load and traffic data, laboratory testing of materials, establishing correlations with the new material inputs, field testing for establishing the initial serviceability index of new construction, and selection and monitoring of field test sections for calibration of local conditions. The implementation of the Guide for the Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures (Design Guide) as a standard design practice will also require significant changes to pavement design procedures, testing procedures and equipment, traffic data input, climatic data input, performance criteria, and others. The Design Guide performance models are calibrated using data from the Strategic Highway Research Program (SHRP) Long Term Pavement Performance (LTPP) Program. To maximize the benefits of the Design Guide, agencies will need to embark on an implementation process to ensure that all of the input parameters are acceptable and practical for their location. The Design Guide provides a hierarchical methodology with three levels of design ranging from Level 1 (detailed project specific inputs) to Level 3 (default regional inputs). This paper presents the material characterization input and testing required for use in the Design Guide.