A Critical Review of Fire Effects on Asphalt Pavements: Mechanical Performance, Environmental Impacts and Design Considerations

Fire incidents happen worldwide and pose potential hazards for human health, the environment, and civil infrastructures. Among the various infrastructures, roads paved with asphalt mixtures are particularly susceptible to fire damage due to the high flammability of binders. Most existing studies focus on using fire additives to preserve asphalt pavements from severe fire damage. However, there is a notable lack of research that addresses the design of asphalt mixtures with fire resistance considerations. Designing fire-resistant asphalt mixtures can be an innovative strategy to mitigate fire impacts on pavements. This includes incorporating fire considerations into every stage of asphalt pavement production, such as material selection, mix design, and production technologies. This paper presents a critical review of the effects of fire on the mechanical performance of asphalt mixtures and identifies key production-related factors influencing their fire behavior characteristics. Additionally, the environmental impacts of fire on asphalt pavements and methods to reduce their susceptibility to fire are investigated. This paper also systematically analyzes the effectiveness of various fire-retardant additives in terms of fire retardance capabilities, effects on pavement mechanical performance, and environmental implications. Finally, a framework for designing fire-resistant asphalt mixtures is suggested. This review aims to provide pavement engineers and researchers with evidence-based strategies for improving asphalt mixture designs in fire-prone areas.