What should be the water content of the material during compaction for crushed stone bases and sub-bases for flexible pavement?

The correct answer reflects that during the compaction of crushed stone bases and sub-bases for flexible pavement, the optimal water content should be maintained within ± 1.5% of the optimum moisture content. This range is crucial because it ensures that the aggregate particles can effectively interlock and achieve maximum density, which is vital for the structural integrity and longevity of the pavement.

Maintaining appropriate moisture levels aids in the proper lubrication of particles, which can enhance the compaction process. If the water content is too low, the particles may not bond effectively, leading to weak points and potential failure in the pavement structure. Conversely, excessive moisture can lead to over-saturation, which may weaken the base material and create instability.

Thus, adhering to this specific moisture range of ± 1.5% is aligned with best practices in asphalt pavement construction, ensuring the necessary balance for optimal compaction while maintaining the desired engineering properties of the crushed stone materials.