Static compaction machinery utilizes the gravity of the rollers to cause permanent deformation and compaction of the compacted layer. The rollers are classified as: smooth rollers, grooved rollers, sheep's foot rollers, and pneumatic tire rollers. Smooth rollers produce a smooth, flat surface and are the most widely used, suitable for compacting various road surfaces, subbases, airport pavements, and plazas.
Grooddling and sheep's foot rollers provide higher unit pressure and thicker compacted layers, suitable for compacting roadbeds and embankments. Pneumatic tire rollers have adjustable tire pressure, allowing for increased or decreased weight, resulting in variable unit pressure. The compaction process has a kneading effect, ensuring a uniform and dense compacted layer without damaging the road surface, making them suitable for compacting subbases for roads and plazas. Impact compaction machinery relies on the impact force of machinery to compact the soil. Types include fire rammers operating on the principle of a two-stroke internal combustion engine, frog rammers operating on the principle of centrifugal force, and high-speed impact rammers operating on linkage mechanisms and springs. Their characteristic is a large compacted layer, suitable for compacting small areas and foundation pits. Vibratory compaction machinery uses mechanical vibration to rearrange material particles through resonance, resulting in compaction, such as plate vibratory compactors. Its characteristics include high vibration frequency, which is effective for compacting loose soils and rocks with low cohesion, such as sand and gravel. Combined-action compaction machinery includes vibratory rollers that combine rolling and vibration actions, and impact rollers that combine rolling and impact actions. Vibratory rollers, which combine rolling and vibration actions, are created by adding a vibrator to a roller and are the fastest-growing type of machine, showing a trend of replacing static rolling compactors.
