I’ve organized this into a clear, direct comparison you can use for exams or interviews:

1. Single-Drum Roller

• Appearance: One large steel drum at the front, two tires at the rear.

• Main use: Compaction of subgrade, soil base, and cement-stabilized base.

• Principle: Dead weight + vibration, with deep compaction effect.

• Features: Deep compaction, high force, suitable for lower structural layers.

• Not suitable for: Asphalt surface courses (easy to crack or push asphalt).

2. Tandem-Drum Roller

• Appearance: Two steel drums, front and rear, both capable of vibrating.

• Main use: Breakdown rolling and intermediate rolling of asphalt pavements.

• Principle: Vibration + static pressure.

• Features: High smoothness, suitable for upper pavement layers.

• Suitable for: Fine compaction of asphalt and cement-stabilized layers.

3. Pneumatic-Tired Roller

• Appearance: Multiple rubber tires (e.g., 5 front, 4 rear).

• Main use: Intermediate rolling and finish rolling of asphalt pavements.

• Principle: Static pressure + kneading effect.

• Features: Good sealing, making the pavement denser and smoother.

• Advantage: Does not damage asphalt aggregates, improves pavement water resistance.

One-Sentence Summary

• Single-drum: Compacts subgrade and base (deep compaction).

• Tandem-drum: Compacts asphalt surface courses (smooth finish).

• Pneumatic-tired: Compacts asphalt final surface (dense, glossy finish).