What are typical indicators of adequate compaction in base and sub-base?

What are typical indicators of adequate compaction in base and sub-base?

• A. High void content, rough surface texture, and rutting.
• B. Low void content, high density readings, and absence of excessive dust.
• C. Absence of any surface indications after compaction.
• D. Low void content, high density readings, and absence of excessive dust or rutting after compaction.

Answer: (D)

Adequate compaction means the base or sub-base is packed so tightly that only a small amount of air remains and it can reliably support the pavement above. This shows up as a low void content and high density readings, ideally approaching the material’s maximum dry density, which you confirm with field density tests. A surface that is not overly dusty and does not exhibit rutting after compaction also signals that the layer has consolidated and can resist traffic loads without deforming. Put together, these indicators—low voids, high density, and a clean, stable surface—point to a properly compacted base or sub-base.

Adequate compaction means the base or sub-base is packed so tightly that only a small amount of air remains and it can reliably support the pavement above. This shows up as a low void content and high density readings, ideally approaching the material’s maximum dry density, which you confirm with field density tests. A surface that is not overly dusty and does not exhibit rutting after compaction also signals that the layer has consolidated and can resist traffic loads without deforming. Put together, these indicators—low voids, high density, and a clean, stable surface—point to a properly compacted base or sub-base.