Railway Geotechnics Routledge Handbooks
Loose ballast tends to have a unit weight of 90100 lb/ft 3 ( Mg/m 3), while that for compacted ballast is approximately 110 lb/ft 3 ( Mg/m 3) . In Table, fouling index refers to the amount of ballast contamination. While this is a small change in unit weight, the associated engineering behavior changes distinctly.