What is the maximum allowed uniform layer thickness after compaction for granular base materials for crushed stone bases and sub-bases for flexible pavement?

The maximum allowed uniform layer thickness after compaction for granular base materials, specifically for crushed stone bases and sub-bases intended for flexible pavement, is an important parameter in pavement design and construction. A layer thickness of 150mm is recognized as optimal because it balances the need for adequate load distribution and the ability to achieve proper compaction.

When the layer is too thick, achieving the required compaction becomes challenging, which can compromise the layer's structural integrity and overall performance. A thickness of 150mm allows for effective compaction while minimizing the risk of deformation or instability in the pavement structure under load. This thickness also facilitates better drainage and reduces the potential for moisture-related issues.

Thicker layers, such as those exceeding this limit, can lead to difficulties in ensuring uniform density and strength across the entire surface, which is critical for the longevity and durability of the pavement. Therefore, adhering to a maximum thickness of 150mm is in line with best practices in construction and engineering standards for ensuring the performance of flexible pavements.