What do anti-strip additives achieve in asphalt mixtures?

Anti-strip additives are crucial in asphalt mixtures as they significantly enhance the adhesion between the asphalt binder and aggregates. When moisture is present, it can lead to stripping, where the asphalt binder separates from the aggregate. This can compromise the integrity and lifespan of the pavement. Anti-strip additives work by chemically altering the properties of the asphalt or the aggregates, improving the bond between them and thus preventing moisture-related stripping issues. This improved adhesion ensures that the asphalt mixture maintains its strength and durability under varying environmental conditions.

The other choices, while related to different aspects of asphalt performance, do not accurately describe the primary purpose of anti-strip additives. For instance, enhancing the color of asphalt is unrelated to the functional benefits offered by anti-strip additives. Similarly, reducing the overall weight of the asphalt mix and preventing asphalt from becoming brittle pertains to different material properties and performance characteristics, rather than the specific role of anti-strip additives in improving adhesion.