Thermal–environmental effects on degradation of railway ballast aggregates: a climate change perspective

Abstract Climate change represents one of the most significant challenges affecting the behavior of materials and infrastructures. This phenomenon can lead to excessive increases or decreases in temperature, heightened sandstorms, increased sulfate attacks and exacerbated freeze–thaw cycles. Among the infrastructures perennially exposed to climate change are railway tracks. In ballasted railway tracks, the ballast layer is affected by various factors such as freezing and thawing, extreme temperatures and attacks by various sulfate salts which can accelerate the degradation of ballast aggregates. Considering that most of the maintenance costs of railway tracks are associated with the deterioration of the ballast layer, the impact of climate change and environmental conditions on ballast durability is examined in the current study. To achieve this goal, a comprehensive experimental investigation was conducted through a series of laboratory tests. Specifically, the durability of ballast aggregates under various states, including environmental temperature changes ranging from − 20 °C to + 100 °C, freeze–thaw cycles, and sulfate attacks, was assessed by simulating these conditions in a laboratory environment. The durability properties of ballast in these conditions were evaluated using different indices such as Los Angeles abrasion, micro-Deval wear, crushing resistance, impact performance, and breakage potential. The results indicate that the durability performance under sulfate attacks, freeze–thaw cycles, and extreme cold and warm temperatures deteriorated by an average of 50%, 20%, 40%, and 35%, respectively. Interestingly, the obtained results also led to a series of insightful empirical formulations to estimate the ballast degradation indices accounting for the impacts of thermal and environmental conditions. These findings highlight a notable impact of thermal and environmental conditions on the durability of ballast aggregates.