Laser-based approach for determining flakiness index of aggregates used in pavements

Abstract

There are concerns about the standard methods/procedures for quantifying shape properties of rock aggregates used in road and airfield pavements. The CSIR has recently acquired a portable three-dimensional (3D) laser scanning device to address some of these concerns, i.e., to automate the determination of aggregate shape properties including form, angularity, texture, and flatness/flakiness. This paper presents a new approach to determine the flakiness index of rock aggregates used in pavements. The 3D laser device was used to directly measure the volume of aggregate samples used in five typical South African asphalt mixes. The results obtained from the laser device were used to compute flakiness index of the aggregate samples. The computed flakiness indices were in good agreement with the measurements from the standard methods, thus validating the correctness of the laser approach and the effectiveness of the volume method to compute flakiness index.