What is the impact of aggregate size on pavement performance?

The correct answer highlights that larger aggregates can enhance both strength and stability in pavement performance. Larger aggregates typically contribute to better load distribution within the pavement structure and can create a more robust interlock between particles. This interlocking effect helps to resist deformation under load, particularly in areas subject to heavy traffic.

Moreover, the use of larger aggregate can improve drainage, reducing the risk of moisture-related damage. When water is able to drain through a coarser aggregate matrix, it can help minimize issues such as swelling or erosion that might occur in finer materials.

In contrast, smaller aggregates may lead to a more dense mix, which can increase workability but might not provide the same load-bearing characteristics as larger aggregates. The performance of the overall mixture is influenced by the gradation and the size distribution of the aggregates used in the mixture, and the ideal size often depends on the specific application and structural requirements of the pavement. Therefore, the effectiveness of larger aggregates in improving strength and stability is an important consideration in pavement design and aggregate selection.