What does the term "voids" refer to in asphalt mixtures?

The term "voids" in asphalt mixtures specifically refers to the spaces between the aggregate particles. Understanding voids is crucial in asphalt technology as they play a significant role in determining the overall performance of the pavement. Voids can affect the water permeability, strength, and durability of the mixture. If the voids are too numerous or too large, it can lead to issues such as reduced stability and potential moisture damage, which could affect the longevity of the pavement. Evaluating the volume of voids helps in assessing the quality of the asphalt mix and ensures that it achieves the desired properties for successful paving applications.