Relationship between lifespan and mechanical performance of railway ballast

Abstract

As the lifespan is main criterion for selection of the aggregate for ballast and for planningthe maintenance of the railroad, it is important to define relationship between the particle load resistant characteristics and ballast's lifetime in structure. Assessment of the quality of the ballast particles under dynamic and static loading should reflect both, the toughness and hardness, and these can be identified with the values of Los Angeles Abrasion and micro-Deval Abrasion. In order to predict the amount of loads, expressed in cumulated tonnes, the model formerly developed by Canadian Pacific Railroads was adapted. A number of different aggregate mixtures were tested in the laboratory including dolomite and granite rocks. The results were used to assess the gross tonnage possible to transport during the lifetime of ballast until repair or reconstruction should be done. The outcome of this study is the possibility to classify the requirements for aggregates' Los Angeles abrasion and micro-Deval abrasion values attributing them to designed traffic volumes.