What is the effect of high dust content in asphalt mixtures?

High dust content in asphalt mixtures leads to reduced workability, which is a significant concern for paving operations. When the dust content is high, it can fill the voids between the larger aggregates and create a more compact mixture. This reduces the ability of the mixture to flow and be manipulated during the paving process, making it difficult to spread, compact, and ensure proper bonding with underlying layers.

The workability of asphalt is crucial, as it affects the ease with which the material can be handled, transported, and placed on the road surface. A mixture that is too dusty may not compact properly, leading to issues such as voids, uneven surfaces, and potential long-term structural problems in the pavement. Therefore, managing the dust content is essential for maintaining the performance and quality of asphalt mixtures.