A vibratory compaction project requires achieving 98% Standard Proctor Density for a sandy gravel base. If a compactor is making 5 passes per lift, what is a critical parameter an operator must consistently monitor for each pass to ensure uniform compaction?

Question: A vibratory compaction project requires achieving 98% Standard Proctor Density for a sandy gravel base. If a compactor is making 5 passes per lift, what is a critical parameter an operator must consistently monitor for each pass to ensure uniform compaction?

Answer options:

• The ambient air temperature and humidity
• The machine's engine RPM and hydraulic pressure ✅ Consistent lift thickness, moisture content, and uniform coverage
• The tire pressure of the compaction unit

Correct answer: Consistent lift thickness, moisture content, and uniform coverage

Explanation: Consistent lift thickness, maintaining optimal moisture content, and ensuring uniform coverage (no missed strips) on each pass are critical for achieving specified compaction density, especially for granular materials.