Verification of Mechanistic-Empirical Design Models for Flexible Pavements through Accelerated Pavement Testing: Fid-Bau Portal

Verification of Mechanistic-Empirical Design Models for Flexible Pavements through Accelerated Pavement Testing

S. Romanoschi / P. Lewis / D. Gedafa / M. Hossain

The Midwest States Accelerated Pavement Testing Pooled Fund Program, financed by the highway departments of Kansas, Iowa, and Missouri, has supported an accelerated pavement testing (APT) project to validate several models incorporated in the NCHRP 1-37A design method, popularly known as Mechanistic- Empirical Pavement Design Guide (MEPDG) for flexible pavements. The following models were investigated: the dynamic modulus estimation model, the relationship between the dynamic modulus and the pavement response; and the relationship between the pavement response (strains) and pavement performance. In addition to these, the experiment aims to compare the performance of the coarse and fine Superpave mixes, and to validate and calibrate the Asphalt Pavement Analyzer (APA) and Hamburg Wheel-Tracking Device Tester as screening tools for estimating rutting performance of Superpave asphalt mixes. The experiments were conducted at the Civil Infrastructure Systems Laboratory at Kansas State University. The test program consisted of constructing 12 flexible pavement structures and subjecting them to full-scale accelerated loading tests. The experiment found that the revised Witczak model predicts the dynamic modulus of asphalt concrete mixes with reasonable accuracy. The MEPDG structural response model underpredicted the longitudinal strains at the bottom of the asphalt concrete layers, while the MEPDG over-predicted the permanent deformation in the asphalt layer. The comparison between the results of the laboratory rutting tests performed at 35DGC indicate that results of the Hamburg Wheel Rut Test correlate best with results of the APT experiment, followed by those from the APA.