Major and minor elliptical axes and bounding rectangle dimensions in clay brick powder particles from changing milling conditions

Abstract

Starting from the observation that regular shape parameters such as equivalent diameter, area-perimeter ratio, circularity, compactness and roundness fail to adequately identify shapes of materials, alternative shape parameters are proposed to remedy this shortcoming. In this study, plugins in image analysis are extended to explore the major and minor elliptical axes and bounding rectangle dimensions in clay brick powder particles from changing milling conditions of different masses of clay bricks in ball mill. It turned out that with developed plugins in ImageJ, extracting such shape parameters of clay brick powder samples was not problematic. For the generated reciprocal aspect ratio (RAR) values ranging from 0.51 to 0.53, majority of the particles were noticed to be within the ellipse-inclined shapes. Using the feret major axis ratio (FMR) values for the formulated bounding rectangle dimensions, most particles appeared to be bound in rectangle-inclined shapes. Despite the generated major and minor elliptical axes and bounding rectangle parameters, grinding conditions in this research did not present any significant influence on such shape parameters of CBP specimens. It is believed that the developments of quantifying the major and minor elliptical axes and bounding rectangle dimensions of the CBP particles in this study are ground on solid foundations without need for extensive experimental works. The proposed developments are therefore valid and could be dedicated for characterising pozzolanic materials, because of their interests in cement-based composites.