Date of Award

Winter 2009

Project Type


Program or Major

Civil Engineering

Degree Name

Master of Science

First Advisor

Jo Sias Daniel


This research project investigates methods to determine the effective PG grade of asphalt binder in a mixture containing Recycled Asphalt Pavement (RAP). Indirect Tensile (IDT) dynamic modulus and strength testing was done on mixtures containing 10%, 25%, 40% RAP and virgin mixtures with different PG grade binders. The Hirsch model was used to backcalculate binder shear modulus from the measured mixture dynamic modulus. The binder was recovered from these mixtures and graded according to SUPERPAVE criteria. These values were compared to the backcalculated binder shear modulus to estimate the effective PG grade. Results of this work show it is a promising method to estimate the effective PG grade, but it does not provide enough information to determine the actual continuous PG grade of mixtures.