Particle shape analysis of coarse aggregate using digital image processing

The particle shape characteristics of the coarse aggregate used can significantly affect the workability, strength, and durability of the concrete produced. However, traditionally, particle shape measurements have to be done in a manual way that is both cumbersome and time-consuming. Herein, digital image processing (DIP) techniques are used to analyze the particle shape characteristics of coarse aggregate. The main particle shape characteristics measured are flakiness and elongation. Twenty-five aggregate samples of different rock type and size have been analyzed and the results are compared to results obtained by the traditional manual method. Strong correlation between the DIP and manual measurement results is achieved and thus the DIP method, which is much faster, may be a better alternative for particle shape measurement. In fact, the DIP method yields more information about the particle shape than the manual method. With the DIP method used, it is possible to measure the mean thickness/breadth and length/breadth ratios of the aggregate directly, rather than just the proportion of flaky or elongated particles according to arbitrary definitions. (C) 1999 Elsevier Science Ltd. All rights reserved.