What type of asphalt failure is bleeding?

Bleeding is a type of asphalt failure that results from excessive asphalt binder on the pavement surface. This excess binder creates a shiny, reflective surface that can reduce skid resistance and create a hazardous driving condition. Bleeding typically occurs when the asphalt mixture has too much binder, insufficient air voids, or when the pavement is subjected to high temperatures. The heat causes the asphalt binder to expand and migrate to the surface, creating a thin film of asphalt. Bleeding can also be caused by improper mix design, inadequate compaction, or the use of an asphalt binder that is too soft for the climate conditions. The excess asphalt binder reduces the friction between the tires and the pavement, making it more difficult to stop or steer the vehicle. Bleeding is considered a functional distress because it primarily affects the pavement's surface characteristics and its ability to provide a safe riding surface. It is visually evident as a dark, shiny surface that may be sticky to the touch, especially during hot weather. Therefore, it is considered a surface defect related to the asphalt mix design or environmental conditions.