What is a modified proctor used for?

• A. Asphalt pavement compaction.
• B. Embankment stabilization uses.
• C. Base, sub grade, MSE wall back fill materials.
• D. Surface dressing on roads.

Answer: (C)

The main idea is that the modified Proctor test uses higher compactive energy to determine how densely a soil can be packed. This yields a higher maximum dry density and a different optimum moisture content than the standard Proctor, making it suitable for soils that will carry heavier loads. That higher density target is exactly what is needed for structural earthwork like base and subgrade layers under roads, and for backfill around reinforced structures such as MSE walls, where stability and strength depend on achieving dense, well-graded fill.

So, the modified Proctor is used for base, subgrade, and MSE wall backfill materials because these applications require densification to support loads and control settlements. Asphalt pavement compaction and surface dressing involve different materials and processes, and embankment stabilization uses other criteria or methods, not the high-density targets defined by the modified Proctor.