Laser-based assessment of road aggregate particle shape and texture properties with the aim of deriving comparative models

Research was undertaken using an innovative three-dimensional (3D) laser scanning tool to study the shape and texture characteristics of road aggregate particles. Aggregate materials used for road construction, including G1 crushed rocks of different geological origins, recycled aggregate and alluvial gravel (not used as aggregate) were used for this study. Representative samples were scanned using the laser system to collect 3D aggregate data for analyses and, subsequently, develop comparative models. The objective was to arrange the aggregate particles in a sequence based on their surface texture. Two models were proposed and key aspects evaluated against each other. Ultimately, one model was selected that may be improved and used for further research. The study found that, while it is possible to use the 3D aggregate scan data to produce comparative models, distinguishing between particle shape and texture proved a daunting task. It was also concluded that particle elongation must be considered as a major influencing factor.The Council for Scientific and Industrial Research (CSIR) Strategic Research Panel (SRP) project TA 2001-001. The authors would like to acknowledge the CSIR R&D office for funding this SRP project.http://www.journals.co.za/ej/ejour_civileng.htmlam201