How can segregation in HMA mixtures be defined?

Segregation in Hot Mix Asphalt (HMA) mixtures is best defined as homogeneity in the HMA constituents. This term refers to the consistent distribution of materials—such as aggregates, asphalt binder, and additives—throughout the mixture. Achieving homogeneity is crucial for ensuring that the HMA performs well in terms of durability, strength, and resistance to environmental effects.

When segregation occurs, it means that certain constituents may be unevenly distributed, leading to areas within the pavement that have different characteristics. This can affect the overall quality of the asphalt pavement, making it susceptible to cracking, raveling, and premature failure.

Understanding the importance of homogeneity helps HMA inspectors focus on practices that promote even mixing during production and transportation, ultimately contributing to more reliable and long-lasting asphalt pavements.