The book is concerned with quantifying damage in asphalt mixtures at the micro level. The use of X ray Computer Tomography (CT) a non destructive technique along with image analysis has been described to study the internal microstructural properties of asphalt. Detail on compression and tension compression fatigue tests and scanned in X ray CT has been given. Techniques to convert 2D images into 3D images of the asphalt sample has been discussed.