Imaging Based Size, Gradation and Shape Characterizations ofAggregate Particles Used in Road Pavements

摘要

This paper presents determination of imaging based size, gradation and shape properties of naturaland crushed aggregate particles commonly used in road pavements. An image analysis system,University of Illinois Aggregate Image Analyzer (UIAIA), has been developed to quantify the one,two and three-dimensional (1-D, 2-D, and 3-D) size and morphological characteristics of aggregateparticles. Based on these measurements, the maximum, minimum, and intermediate dimensions ofindividual particles are accurately captured and used to determine the maximum and minimumsizes and gradation of an aggregate sample. With specifically developed algorithms, the 2-Dmorphological characteristics of aggregate particles, I.e., the flat and elongated ratio (F&E ratio),angularity, and surface texture are characterized by the use of quantitative indices depicted by theF&E ratio Index, the Angularity Index (AI), and the Surface Texture Index (ST), respectively, inthe UIAIA system. Algorithms of two other 3-D quantities of an individual aggregate particle, I.e.,the volume and surface area, makes the UIAIA a comprehensive imaging system for quantifying acomplete set of size and morphology classes of aggregates used in road pavements.