Study on Aggregate Size Distribution in Asphalt Mix Using Images Obtained by Different Imaging Techniques

The present paper deals with the application of imaging technique to estimate the aggregate size distribution in asphalt mix. Aggregate size in asphalt mix typically varies by several orders of magnitude. Thus, it may become difficult to use a single imaging technique to assess the entire spectrum of aggregate size distribution. In the present study, different imaging equipment namely, camera, scanner and scanning electron microscope (SEM) are used to capture images of asphalt mix. Each equipment has a upper and a lower size limit within which the aggregates are distinguishable. The images are analyzed to derive information on aggregate size distribution. Performance of the individual imaging techniques on an asphalt mix sample of known aggregate gradation is studied.