Characterization and Evaluation of Different Asphalt Properties Using Microstructural Analysis

Microstructural analyses of asphalt mixtures are described in this chapter using the X-Ray computer tomography (X-Ray CT) and related digital image processing (DIP) approaches. Different parameters of single elements like aggregates or air voids as well as characteristics of the whole grain and void structure, which can be determined, are introduced. These features can be linked to different mechanical, structural and functional properties. Changes of certain parameters by load application (tensile or compressive stress) or by artificial soiling (with porous structures), e.g. in before-and-after studies, are observed and certain conclusions are drawn. Fatigue and deformation of asphalt pavements and related deterioration effects in the microstructure like cracking are presented as exemplary use cases in this chapter as well as drainage and sound absorption of porous asphalt. The virtual reconstruction of asphalt structures based on three-dimensional (3D) images of real asphalt samples is also of great relevance for computational studies, e.g. for finite element modeling, and is shown exemplarily in this chapter. Simplification approaches of the microstructure are discussed in that context briefly as well.