Why is proper aggregate gradation important in asphalt mix?

Proper aggregate gradation is crucial in asphalt mix because it directly influences the strength and durability of the mixture. The gradation refers to the distribution of different sizes of aggregate particles in the mix. An optimal gradation helps in achieving a compact and stable structure, which in turn affects the mechanical properties of the asphalt. Well-graded aggregates ensure that the voids between larger aggregates are filled with smaller aggregates, minimizing air voids and enhancing the overall density of the mix.

This density is vital for the pavement's resistance to deformation under load and its ability to withstand various environmental conditions. Additionally, a well-graded aggregate mix minimizes segregation and improves workability during construction, ensuring a more uniform and durable pavement surface. Overall, proper gradation contributes significantly to the performance and longevity of the asphalt pavement.