What is the main objective of verifying subgrade bearing capacity and surface uniformity before placing concrete?

• A. To accelerate work.
• B. To check only for moisture.
• C. To ensure stable support and uniform surface.
• D. To avoid using formwork.

Answer: (C)

The main idea is to confirm the foundation is ready to support the concrete slab and provide a smooth, level bed for placement. Verifying subgrade bearing capacity ensures the ground can carry the loads without excessive settlement or deformation, which would cause differential settlement and cracking once the slab is in place. Checking surface uniformity guarantees the base is flat and evenly contoured, so the slab thickness stays consistent and the finish can be placed and cured properly. Together, these checks deliver a stable, uniform base that prevents later surface irregularities and structural issues.

This isn’t primarily about speeding up work, nor about moisture alone, and it doesn’t mean skipping formwork. Those elements may be relevant in related aspects of construction, but they aren’t the main objective of this verification.