Which tool is recommended for use on granular subgrades and sandy soils?

The use of a vibratory plate compactor is recommended for granular subgrades and sandy soils due to its effectiveness in densifying these types of materials. This equipment utilizes vibration to improve the compaction process, allowing for better consolidation of loose soil. The vibration helps particles rearrange and settle together more tightly, which is particularly beneficial for granular materials that can easily shift and fail to achieve adequate compaction when using less effective methods.

In sandy soils, this compaction technique is crucial as it helps to avoid future settlement, ensuring a stable base for subsequent construction activities. The vibratory plate compactor is designed to deliver consistent force and create a uniform compaction layer, making it a preferred choice for this type of work.

Other tools, such as a hand tamper, while useful for small areas or in tight spots, may not provide the same level of compaction over larger areas or deeper layers. Additionally, a pneumatic roller is more suited for cohesive soils rather than granular ones, and a concrete saw doesn't serve any purpose in compaction. Each of these other options lacks the specific functionality required for effective compaction of granular subgrades and sandy soils, highlighting the importance of choosing the right tool for the task at hand.