The compaction machinery used has a great influence on the compaction state of the subgrade soil and pavement materials under a certain moisture content. Only a small degree of compaction can be obtained with a light roller. Greater compaction can be achieved with heavy-duty rollers. Vibratory rollers are much better compacted than ordinary smooth drum rollers of the same quality. Not only the density is large, but also the effective compaction depth is large (except for clays with high water content).
1. Compaction Machinery – Static smooth drum roller
When the static smooth drum roller is rolling on the soil (or pavement material) layer, the compressive stress generated under the action of the roller is mainly concentrated on the surface layer. When the smooth drum roller is used for rolling, the unit pressure is small due to the large contact area between the rolling wheel and the soil or pavement structural layer material, and the compaction work is carried out from the surface of the compacted layer downward, and the upper layer is denser than the lower layer. , therefore, the compaction thickness of the smooth drum roller is smaller. Rolling a certain thickness of fill soil and pavement structure layer with a smooth drum roller can not only obtain a dense result but also obtain a smooth surface.
2. Compaction Machinery – Tire Roller
The tire roller uses the variability of the pneumatic tire and its suspension device to maintain a certain contact surface between the tire and the soil layer. Because it has the advantages of adjusting its own total mass by increasing or decreasing the additional load, large contact surface with the compacted soil layer or material layer, and large effective compaction depth, it is increasingly widely used to compact various earthwork materials and pavements. structural layer. But tire rollers are better for compacting clay soils. Due to the certain kneading effect on the pressed material and the difficulty of crushing aggregates when rolling with a tire roller, white-line tire rollers are often used to roll various asphalt surfaces, especially for spray-type asphalt surface treatment and asphalt penetration. Into the surface layer, can get a good compaction effect.
3. Compaction Machinery – Vibratory roller
The compaction function of vibratory rollers is very strong, and vibratory rollers are generally equipped with frequency modulation and amplitude modulation devices, which can be adjusted to different conditions of no vibration, weak vibration, or strong vibration according to needs. Thus, it can be used as a light, medium, and heavy roller. It has the advantages of small quality, small size, high speed, high efficiency, and flexible operation. The vibratory roller is especially suitable for compacting low-viscous soil, sand and gravel, crushed stone mixture, and various binders to treat graded aggregates. It is even more necessary to use a vibratory roller for the gravel-filled base. Small walk-behind vibratory rollers are especially suitable for rolling shoulders and backfills.