Effects of Two Different Types of Fines on the Compression Behaviour of Clean Ballast

Abstract This paper investigates the influence of fines on the strength properties and deformation characteristics of abraded ballast fouled with two kinds of fines: a fouling made by stone dust of the same parent rock and a clay-based fouling made of kaolinite particles. The results of these tests showed that the fouling containing clay reduces strength owing to a lubricant effect permitting the rearrangement of grains, while the natural fouling has strengthened the sample. As far as fractures are concerned, the introduction of small particles induced fewer fines in both cases, probably meaning a more homogeneous force distribution around the large particles. More studies are in progress to clarify this phenomenon.