This thesis discusses and documents the validation efforts related to Ontario’s LS-299 and LS-308 test methods which are two new test methods developed for the performance-based specification grading of asphalt cement. In addition, this report presents the field validation of a simple performance indicator, loss tangent, for specification grading of asphalt cement for thermal cracking. Furthermore, another objective of this study is to investigate and compare the low temperature fracture and rheological behavior of engineered asphalt materials from field and laboratory-aged test sections on Highway 655 in northern Ontario. Extracted asphalt cements from 20 contract sites in eastern and northeastern Ontario were tested according to Ontario’s LS-299 and LS-308 test methods. It was found that all good performing contracts that showed little or no distress showed low grade losses in LS-308 and retained high strain tolerances as measured in LS-299 compared to the poor performing contracts. Asphalt cements recovered from these 20 contract sites in eastern and northeastern Ontario were also tested in torsion bar geometry to determine their viscoelastic properties. It was decided to focus on the phase angle, as a more direct measure for low temperature performance. Phase angle is a very sensitive parameter to small changes in rheology as the phase angle is approximately equal to the derivative of the logarithm of the stiffness with respect to frequency. It was found that tan() was able to distinguish good from poor performers with 95% accuracy after only a short period of conditioning prior to testing. This is a considerable improvement over the current low temperature bending beam rheometer protocol. Black space diagrams, frequency sweeps, Cole-Cole plots, and master curves were generated for comparison of field and laboratory aged materials from the Highway 655 trial in northern Ontario. The findings show that chemical hardening occurs much faster in the field than through laboratory ageing methods. Also, reversible ageing of binders may occur at low temperatures and could be linked to field performance. Furthermore, a high low temperature phase angle appears to be a reasonable indicator for thermal cracking resistance. / Thesis (Master, Chemistry) -- Queen's University, 2009-08-28 15:12:29.845

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Under some conditions in real world, precise parameters and/or initial values of dynamic systems are hard to be determined. Fuzzy Differential Equation (FDE) is a powerful tool to model dynamical systems with the uncertainty of impreciseness. This thesis presents the first numerical solution for Fuzzy Differential Equations with multiple fuzzy parameters and initial Values (FDEPIV) problems. Previous approaches for solving the FDEs only focused on FDEs with single fuzzy condition. In this thesis, we applied the proper fuzzy arithmetic on Runge-Kutta method for solving the FDEPIV problems with multiple fuzzy parameters and initial conditions. Furthermore, comparing with directly applying the extension principle in solving FDEPIV, the complexity of the proposed method is much lower, and parallelization of the proposed algorithm is feasible. Numerical examples of the FDEPIV problems are presented to demonstrate the effectiveness of the proposed method.

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Nanocrystalline materials could exhibit high mechanical yield strength. Nevertheless, with a high volume fraction in nanocrystalline material, grain boundaries and triple junctions which store a relatively high free energy, are thermally instable which potentially contribute to grain growth. On the other hand, since both grain boundaries and triple junctions are prior sites of impurity enrichment which could in return reduce the triple junction energy, alloys with impurity enriched in grain boundaries and triple junctions are widely applied to stabilize the nanostructures. However, past studies mainly focused on grain boundaries and the kinetic properties of triple junctions and their influences on the thermal stability of nanocrystalline metals is less studied. In this work, triple junction mobility and impurity diffusivity in triple junction are studied by molecular dynamics simulations. Specifically, interface random walk method due to thermal fluctuation which has been widely applied to extract grain boundary mobility is extended to study triple junction motion.