WORKSHOPS and SEMINARS

Dynamic Modulus E* Characterization of HMA Mixes for Implementation of PMED

ABSTRACT
The recently developed Pavement Mechanistic Empirical Design (PMED) software uses the dynamic modulus (E*) of asphalt concrete (AC) as a major input that directly affects the rutting and fatigue model in the PMED software. This talk will cover how to generate this input from the field collected Superpave mixes and use it in the PMED design software efficiently. In essence, this talk will cover mix compaction using a gyratory compactor, cylindrical samples preparation using lab saw and coring, cylinder testing for E* at different temperatures and loading frequencies, and development of E* predictive model/equation to conduct level 2 PMED analysis. In addition, this workshop will cover how this model uses aggregate gradation data as well as asphalt binders’ dynamic shear modulus (G*) obtained in the laboratory. This workshop will also cover how a sigmoidal function is fitted to the laboratory E* data to develop master-curves using regression methods, and how the model fitting parameters are determined, and how the parameters are directly supplied as inputs of PMED software.

BIO
Dr. Rafi Tarefder is a Professor of Civil Engineering and Regents’ Lecturer at the University of New Mexico (UNM). He serves as an Associate Director of Southern Plain Transportation Center (SPTC), and Director of New Mexico Transportation Center. Dr. Tarefder’s research work covers a wide spectrum, from applied and design-focused to theoretical, principally in pavement materials and design. He has published 427 (187J, 240C) peer-reviewed journals and refereed conference articles including two best paper awards. He has authored 1 textbook and 6 book chapters; edited 6 books and journal special issues, published 45 major research reports, and filed 2 patents. Dr. Tarefder is the Chair of the Annual Paving and Transportation conference, which is the biggest in the southwest, having an attendance of more than 700 participants. He is an associate editor of ASCE’s International Journal of Geomechanics. He is a licensed professional engineer in NM and Idaho.