THE DEVELOPMENT OF A COMPUTER CONTROLLED IMAGE ANALYSIS SYSTEM FOR MEASURING AGGREGATE SHAPE PROPERTIES

This Innovations Deserving Exploratory Analysis (IDEA) project developed and tested a prototype of an automated image analysis system for measuring aggregate shape characteristics. A review of available methods for analyzing aggregate shape features was performed and a procedure for measuring aggregate texture was developed. A software that incorporated several image analysis procedures was developed and applied to measure the texture of a wide range of fine and coarse aggregates. This work was followed by efforts to develop hardware for the image analysis system. The hardware incorporated a computer-controlled mechanism to allow capturing different projections of aggregate particles and describing their shape properties rapidly and accurately. A user-friendly version of the software was also developed to facilitate data presentation and manipulation. The hardware and software were integrated to produce a prototype of the automated aggregate analysis system. The system was tested on a range of fine and coarse aggregates and the results were compared with hot mix asphalt performance data. The image analysis procedure was found to provide detailed information on shape properties of aggregates in a short time. The shape measurements also showed a good correlation with the resistance of asphalt mixes to permanent deformation measured in the laboratory using different wheel tracking devices.