I. Core Difference (One Sentence)

Static compaction: Relies only on its own weight to press down, like flattening with a stone.

Vibratory compaction: Uses weight + high-frequency vibration together, like pressing while shaking to compact the material tightly.

II. Detailed Comparison

1. Working Principle

• Static compactionRelies on the vertical pressure generated by the roller’s own weight to compact and level the material.

• Vibratory compactionThe steel drum contains an eccentric block that rotates at high speed to produce high-frequency vibration. This rearranges aggregates, eliminates voids, and achieves much higher density than static compaction.

2. Compaction Effect

• Static compaction

• Medium density

• Mainly used to remove wheel marks and improve smoothness

• Vibratory compaction

• Much higher density

• Can reach the required compaction standard; the main method for subgrade, cement-stabilized layers, and asphalt

3. Applicable Scenarios (Most Important)

👉 Static compaction is used for:

• Initial and final rolling of asphalt pavements

• Finishing and leveling when compaction is nearly complete

• Thin layers and structurally fragile sections to prevent damage from vibration

👉 Vibratory compaction is used for:

• Subgrade soil and sand-gravel cushions (must be vibrated to achieve full compaction)

• Cement-stabilized crushed stone base

• Intermediate rolling of asphalt pavements (main compaction stage)

III. Site Memory Formula (Easy to Remember)

Static compaction: levels, finishes, and avoids vibration damage.Vibratory compaction: fully compacts, densifies, and does the main work.

Three steps for asphalt:static initial rolling → vibratory intermediate rolling → static final rolling.

Simple summary:Static compaction handles smoothness;vibratory compaction handles density.