A New Simplistic Model for Dynamic Modulus Predictions of Asphalt Paving Mixtures

This paper presents a new mechanistic empirical model for predicting dynamic modulus of asphalt paving mixtures at a wider range of temperatures and loading frequencies, which can be shifted into a master curve for characterizing asphalt concrete. Available predictive models seem to be not capable of predicting dynamic modulus of asphalt mixtures at higher temperatures and lower loading frequencies; these models over-predict dynamic modulus by a significant deviation from laboratory-measured values. The new model is capable of accurately predicting measured dynamic modulus at a broader range of temperatures and loading frequencies. The proposed new model was derived from the law of mixtures where composite materials are modeled in a combination of parallel and series phases. For a system of purely parallel phases, the combined mechanical behavior is simply the addition of the responses from these phases. To develop the new model, asphalt mixtures with different performance grades covering highly modified and unmodified asphalt binders were tested in one of the marketed simple performance test (SPT) devices to measure dynamic modulus. The new model is simple in its formulation, and needs no more than one input from the asphalt binder; the dynamic shear modulus (*G), and one input from the mixture; the voids in mineral aggregate (VMA).