| Quantification of the microstructures of granular particles, assemblies and mixtures and the evaluation their effects on material properties constitute the subject of this research, in which imaging techniques have been extensively used.; Morphology is the study of form and structure whereas imaging techniques are viable techniques that can implement the study. In this thesis, a morphology descriptor-particle signature for an aggregate profile was defined and quantified using an imaging technique. The particle signature includes shape, surface roughness and surface texture components and can be used to reproduce the aggregate profile and abstract features.; For bonded granular materials such as asphalt concrete, interfaces between the different components are important. A novel procedure using an imaging technique was developed to quantify the specific surface areas of aggregates in different size ranges. The quantified specific surface area can take into account the shape and surface roughness.; The distribution of doublet vectors, branch vectors and contact normal is an important quantity in micromechanics of granular materials. A new procedure was developed to quantify the axial-symmetric distribution of doublet vectors of the mixture of spherical and sub-spherical particles. The procedure was applied to the quantification of the doublet vector distribution of an Ottawa-sand specimen. The quantified distribution was then correlated to macro properties of the specimen for indirect verifications. A new method to estimate the moduli of resin-aggregate composite from the moduli of its components was developed by using the aggregate skeleton moduli that can take into account strong particle interactions.; To relate macro-responses with particle translations and rotations, a novel method was developed to measure the permanent macro strains and the permanent strains in the mastic. The new method allows for automatic tracking of particles by a pattern recognition technique. The quantified macro strains and the strains in the mastic demonstrated strong configuration dependency. Findings from these measurements have important implications in constitutive modeling and material characterization of asphalt concrete.; Finally, the three-dimensional (3D) morphology representation of an aggregate particle was obtained through reconstructing the sliced sectional images. The specific surface area, sphericity were computed from the reconstructed 3D structure. A possible extension of the procedure to the microstructure reconstruction of granular assemblies and mixtures is discussed. |
