Aggregates have to fulfill several quality requirements dependent on the field of use. The main physical characteristics include grain-size distribution, shape, mineralogical composition, durability, chemical resistivity, angularity and roughness. Several methods exist to characterise these properties. Sieving has traditionally been used for evaluating the grainsize distribution while manual measurements by gauge or ruler-box have been used to determine the main dimensions and shape of individual particles (Smith and Collis, 1993). Image analysis methods have been developed for both size and shape analyses