Coarse Aggregate Shape and Size Properties Using a New Image Analyzer

    Volume 29, Issue 5 (September 2001)

    ISSN: 0090-3973

    CODEN: JTEOAD

    Page Count: 11


    Rao, C
    Graduate research assistant and assistant professor, University of Illinois at Urbana-Champagne, Urbana, IL

    Tutumluer, E
    Graduate research assistant and assistant professor, University of Illinois at Urbana-Champagne, Urbana, IL

    Stefanski, JA
    Staff engineer, Eres Consultants, a Division of ARA, Champaign, IL

    (Received 6 December 2000; accepted 2 April 2001)

    Abstract

    Automation of coarse aggregate shape and size determination using image analysis techniques is described in this paper as an alternative approach to current manual and time-consuming test procedures. A new image analyzer system, referred to as the University of Illinois Aggregate Image Analyzer (UI-AIA), uses a three-camera setup to view each aggregate particle from three orthogonal directions. Both volume (and therefore weight) and shape factors can be determined precisely for each particle based on sound image analysis and geometric principles. In addition, the grain size distribution of an aggregate sample can be determined. Tests conducted on ten aggregate samples were used to evaluate the perfor mance of the laboratory prototype UI-AIA in automating the standard ASTM D 4791-99, Standard Test Method for Flat Particles, Elongated Particles, or Flat and Elongated Particles in Coarse Aggregate and ASTM C 136-96a, Standard Method of Test for Sieve Analysis of Fine and Coarse Aggregates. The accuracy and repeatability of the imaging technique were evaluated for the computed aggregate volumes, percent by weight flat and elongated ratios, and gradation curves. Results from the new UI-AIA were in very good agreement with the manual measurements performed in two separate laboratories to ensure their exactness. The UI-AIA has scope for further modifications and improvements.


    Paper ID: JTE12276J

    DOI: 10.1520/JTE12276J

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    Author
    Title Coarse Aggregate Shape and Size Properties Using a New Image Analyzer
    Symposium , 0000-00-00
    Committee D04