Aggregate Particle Size Calculation Based on Optimized Equivalent Ellipse

Abstract

The precise calculation of the aggregate size is crucial for detecting aggregate gradation. Therefore, the aim of this study was to propose a method for calculating aggregate particle size. First, a series of image-processing methods, such as filtering, enhancement, segmentation, and morphology, were implemented to obtain a binary image. Consequently, a method for determining the particle shape and correcting the particle size was devised. The aggregate particles are divided into four categories, i.e., rectangle, ellipse, diamond, and triangle, according to three parameters: compact factor, projected contour, and distance distribution from edge point to centre of mass. The corresponding correction coefficient of each category based on the equivalent elliptical minor axis was then calculated, and the grading accuracy of the corrected particle size was analyzed. The accuracy of the particle size classification obtained by the method of aggregate particle shape determination and particle size correction proposed in this paper is 80.7 %.