LASS Incorporates the Third Dimension in Order to Improve the Accuracy of Rapid-Gradation Technology

"Sophisticated asphalt designs, such as the Superpave specification, specify aggregate shape parameters like flatness and elongation ratios as an additional design variable. Conventional sieve analysis has drawbacks such as: poor efficiency and accuracy; labor intensiveness; time consumption; subjectivity; inability to measure shape parameters; and inability to measure irregularly shaped particles accurately. Although several rapid-gradation devices are currently on the market, their appropriateness and cost effectiveness for various applications in both the laboratory and in the field has yet to be determined. The research team evaluated five commercially available rapid gradations devices for accuracy and performance using fifteen aggregate test samples of various size, shape, and minerology. The project uses several methodologies in characterizing accuracy and studies two technologies in detail: digital-image analysis and laser profiling. The second part of the final project developed a laser scanning device for grading aggregates"