Rheological investigation of asphalt and asphalt concrete

The performance of an engineering material is determined by the relationship between the stress and the strain in the material. Asphalt binders and asphalt mixes are viscoelastic materials which can be characterized, in the linear viscoelastic domain, by various material functions. The rheological behavior of four different commercial binders from western Canadian heavy crude oil sources and asphalt concretes prepared with these binders are described in this thesis. It is shown that there is a definite relationship between asphalt binder and asphalt concrete rheological behaviors at high, medium and low temperature.;At low temperatures the horizontal shift factor points to different susceptibilities of the materials. Asphalt binder and asphalt mix depict similar creep compliance trends. A correlation between the logarithms of creep compliance and thermal stresses for binders and asphalt concretes was found. For binders, isothermal storage can have a large effect on their material properties; the extent of hardening in asphalt concretes is reduced when compared with the hardening in binders.;The difference in high temperature Superpave classification of the binder used in the mixes was reflected in the asphalt concrete fatigue and high temperature behavior. A relation between asphalt concrete behavior and asphalt binder rheological characteristics was observed. The feasibility of using the linear viscoelastic theory for the description of the repeated creep and recovery experiments in the tested materials was shown.;Both, asphalt binder and asphalt mix exhibit a linear viscoelastic behavior when the input variable i.e. strains or stress is small. The use of the complex dynamic modulus in axial compression mode seems to be sufficient for the viscoelastic description of asphalt concrete. It was found that asphalt binders and asphalt concretes have practically the same values of horizontal shift factors. The horizontal shift factors in asphalt mixes seem to be not dependant on the asphalt mix granulometric composition. A correlation between the logarithms of magnitudes of complex moduli of asphalt binders and asphalt concretes was found.