As a contribution to the development of mutli-scale multi-physics approaches to modelling pavement performance, the present thesis considers the topic of damage accumulation accompanied by damage recover self-healing of the bituminous asphalt phase of pavement systems. It is found insightful that by adopting Hveem’s [1943] concept of attributing pavement failure modes to the “chemical action” of the asphalt binder, a theory of asphalt binder chemomechanics may be developed to link material composition derived in terms of binder physicochemical properties to rheology and thus to mechanical response. The chemomechanics theory considered herein reflects the working hypothesis that damage accumulation accompanied by damage recovery self-healing in the bituminous asphalt binder phase of a pavement system is influenced by the multi-phase nature of the binder. Chapter 2 provides a fundamental basis for the theory considered, formulated based on the net entropy production in a damage-healing process expressed as the sum of free energy per thermodynamic variable terms. A prominent theme of the chemomechanical model/theory discussed in this thesis relies on the development of a hierarchical approach to define an ansatz net entropy production equation in terms of the principle force-flux pair contributions to damage accumulation and damage recovery healing propensities in the asphalt binder phase of a pavement system. In chapter 3 studies of fatigue damage and healing in asphalt pavements, as reported by Little et al. [Little et al. 1998, 1999; Kim et al. 2001; Williams et al. 2001], defined in part by the wetting/de-wetting mechanism of the asphalt binder bonding to and de-bonding from “fines” aggregate surfaces, as defined in terms of the bond strength of the asphalt-fine aggregate interface are reviewed in detail. Surface free energy properties of asphalt binders are then shown to relate to the chemical composition of the binder. Specifically, surface free energy properties of asphalt chromatographic fractions are shown to be related to Lifshitz Van der Waals and Lewis Acid/Base surface energy components, which are responsible for the wetting/de-wetting mechanisms and the bond strength of the asphalt-aggregate interface. In chapter 4 the physicochemical properties of asphalt fractions, specifically asphaltene content and molecular weight distribution of the maltene and oils phases of binders are shown to govern the temperature dependent flow properties of the binder. Here variations in the average molecular weight distribution of the continuous phase molecules directly correlate with variation in viscosity among binders derived from different crude sources. Temperature dependency of viscous flow of the whole asphalt binder can then be correlated directly to temperature dependent viscous flow properties of the continuous phase in terms of Eyring's activated state kinetics model of viscous flow [Ewell and Eyring 1937]. Furthermore suspension phase concentration defined in terms of asphaltene are shown to directly influence the whole asphalt binder flow properties, particularly the elastic nature of the material as measured in terms of the rheological phase angle, ?. Flow properties of asphalt binders, particularly activation energy of flow, are shown to predict healing rates. It is also generally observed that more compatible asphalts (i.e., asphalts which exhibit “more” Newtonian-like flow properties, higher viscous flow sensitivity to temperature change, and generally more ductile) exhibit better healing properties. Conversely, stiffer, less compatible asphalts are expected to exhibit a greater propensity to fracture due to their brittle, less ductile properties. In chapter 5 environmental factors which promote modes of pavement failure which directly influence the embrittlement of asphalt pavements are considered, these include temperature swings which lead to thermal fatigue, and oxidative age hardening of the asphalt which compounds repetitive load fatigue and diminishes healing. In chapter 6 the interaction between crystallizing paraffin waxes and the remaining non-wax asphalt components is shown to be responsible for much of the structuring, including the well-known bee-structures that have been observed on the surface of asphalt thin-film samples as imaged by AFM [Pauli et al 2011]. The phenomena of surface freezing (SF) of mono layer single-crystals which commonly occurs with chain molecules like n-alkanes is proposed as a plausible mechanism for the formation of surface structuring in asphalt binders and asphalt fractions. Based on the findings reported in this chapter wax crystallization is considered a key contributor, participating in mid-temperature, to fatigue and healing in pavements. It is thus proposed that a better understanding wax crystallization in asphalt should lead to a fundamentally better understanding of both low- and mid- temperature pavement properties. In chapter 7 finite element simulations are carried out to evaluate damage accumulation in composite biphasic systems of surface microstructuring as commonly observed in bituminous asphalt binders by atomic force microscopy (discussed in chapter 6). Both monotonic loading and cyclic loading simulations of five different biphasic systems show good correlation with morphological properties of the microstructures considered. In a majority of these simulations the microstructured phase are considered to have essentially stiff elastic mechanical properties while the surrounding matrix is considered to be of a softer viscoelastic mechanical type. In particular, the relative “concentration” or amount of structured phase, relative to the surrounding matrix, consistently correlates with damage accumulation parameters simulated in both monotonic and cyclic loading schemes. The modelling and experimental approaches discussed throughout this thesis are anticipated to represent a significant contribution towards the development of mutli-scale multi-physics approaches for modelling asphalt pavement performance. The fundamental basis of these approaches should then lend to prediction of performance of newly introduced materials where the performance behaviours is otherwise unknown.