Development of a Morphology-based Analysis Framework for Asphalt Pavements

Sammanfattning: The morphology of asphalt mixtures plays a vital role in their properties and behaviour. The work in this thesis is aimed at developing a fundamental understanding of the effect of the asphalt morphology on the strength properties and deformation mechanisms for development of morphology-based analysis framework for long-term response prediction. Experimental and computational methods are used to establish the relationship between the mixture morphology and response. Micromechanical modeling is employed to understand the complex interplay between the asphalt mixture constituents resulting in strain localization and stress concentrations which are precursors to damage initiation and accumulation. Based on data from actual asphalt field cores, morphology-based material models which considers the influence of the morphology on the long-term material properties with respect to damage resistance, healing and ageing are developed. The morphology-based material models are implemented in a hot-mix asphalt (HMA) fracture mechanics framework for pavement performance prediction. The framework is able to predict top-down cracking initiation to a reasonable extent considering the variability of the input parameters. A thermodynamic based model for damage and fracture is proposed. The results from the study show that the morphology is an important factor which should be taken into consideration for determining the short- and long-term response of asphalt mixtures. Further understanding of the influence of the morphology will lead to the development of fundamental analytical techniques in design to establish the material properties and response to loads. This will reduce the empiricism associated with pavement design, reduce need for extensive calibration and validation, increase the prediction capability of pavement design tools, and advance pavement design to a new level science and engineering.