Measurement of Aggregate Size and Shape Using Image Analysis

Aggregate quality influences concrete mix design and properties. It is necessary to measure the quality of aggregate. The most popular field test to measure the quality of aggregate is the sieve test. It is not possible to measure shape characteristic and other parameters by sieve analysis. Therefore, it is essential to develop rapid assessment techniques for quality control of aggregate. Selection of methodology for aggregate shape characteristic measurement depends on parameters such as aggregate size, accuracy, reliability of the method, time required to analyze the sample, human efforts required, measurement of other characteristics of the particle apart from the size, the robustness of testing equipment, the initial cost of the equipment, its maintenance and operational costs. Digital image analysis is a process to gather information regarding a characteristic of particle through computer programming. Digital image analysis method has a potential to estimate the characteristics namely, the size and shape of aggregates rapidly and accurately. Twodimensional image analysis of aggregate gives a relative idea of aggregate properties in a more accurate manner as compared to the procedure suggested in Indian standards. This paper summarizes the developments and research in the area of image analysis.