What is "temperature segregation" and why is it problematic in asphalt paving?

Temperature segregation is a phenomenon that occurs when there are uneven temperatures within the asphalt mix during the paving process. This inconsistency can arise due to factors such as material handling, transportation, or improper mixing. When different portions of the asphalt mixture are at varying temperatures, the material's properties change, resulting in an uneven distribution of binder and aggregate. Consequently, this leads to inconsistent performance levels in the finished pavement.

When temperature segregation occurs, some areas may experience brittleness or reduced adhesion while others may remain susceptible to deformation or other distresses. These variations can manifest as ruts, cracks, and surface wear, ultimately affecting the lifespan and safety of the pavement. Addressing temperature segregation is critical to achieving a uniform and high-quality asphalt surface that performs well under traffic loads and environmental conditions.

In contrast, uniform heating of the mix, higher asphalt quality, and enhanced durability of pavements are not outcomes associated with temperature segregation, as these aspects directly contradict the inconsistencies created by temperature variations.