Advanced and automated laser-based technique to evaluate aggregates

Abstract

The Council for Scientific and Industrial Research (CSIR) is undertaking a research project to investigate the use of laser-based scanning technology to quantify the morphological/shape properties (i.e., form - flatness, elongation and sphericity; angularity; surface texture) of aggregates used in pavements and railway ballast. To date, no automated method is available for direct measurements of shape properties of these materials in Africa. The objective of this paper is to present a three-dimensional laser scanning technique to determine flatness, elongation and sphericity of aggregates used in South African roads. A three-dimensional (3-D) laser scanning device was used to obtain the dimensions, surface area, volume, and subsequently, compute flat and elongated ratio of six different aggregate samples. The results were compared with the standard manual method that is currently used by the road industry to quantify aggregate shape properties. It is expected that, this study would influence decisions to improve aggregate material characterization and pavement design.