Morphological Evolution of Andesite Railway Ballast Particle Under Rotating Drum Abrasion Test

Railway ballast is a natural aggregate widely used in railway infrastructure. The mechanical strength and geometric shape of ballast particles have an important role in the durability and maintenance economy of the ballasted track. This paper aimed to investigate the abrasive behavior of andesite ballast particles using a rotating drum abrasion test and 3D morphological shape analysis. The photogrammetric reconstruction method is adopted here and modified to make it more efficient and user-friendly. The evolution of mass, particle shape, and grain indices were compared for different shape classifications. The experimental results show that the evolution of elongation and flakiness that describe overall particle shape is inconsistent during abrasion, whereas the equivalent ellipsoid volume ratio and rotational resistant angle, which mainly describe particle surface angularity evolve gradually throughout this long-term abrasion process. So, the latter two shape indices describe particle abrasion behavior more accurately.