Why is it important to control aggregate gradation in asphalt mixtures?

Controlling aggregate gradation in asphalt mixtures is crucial because it directly impacts the performance characteristics of the pavement. Good gradation of aggregates ensures that a proper distribution of particle sizes is achieved, leading to optimum packing and minimizing voids within the mixture. This results in improved workability, as the mixture can be easily placed and compacted during construction.

Furthermore, a well-graded aggregate blend provides the necessary stability to resist deformation under load, which is essential for maintaining the structural integrity of the pavement. Additionally, it contributes to the durability of the pavement by enhancing its resistance to environmental factors, including moisture infiltration and temperature fluctuations. A pavement that combines these attributes will result in longer-lasting performance, reduced maintenance costs, and a safer surface for vehicular traffic.

Thus, the importance of controlling aggregate gradation cannot be overstated, as it directly correlates to the quality and longevity of the asphalt pavement.