A road roller is a construction machine used in road construction and maintenance, which can compact different materials and layers to improve the smoothness and bearing capacity of the road. Rollers have different wheel shapes because they are suitable for different compaction principles and situations.
Generally speaking, the wheel shape of road rollers can be divided into two categories: steel wheel type and tire type.
1. Drum Roller
The wheels of steel wheel rollers are composed of steel rollers, and the surface of the rollers can have different structures, such as smooth rollers, groove rollers, and sheep foot rollers.
1) Smooth rollers
The smooth roller is a roller with a flat and smooth surface, and its compaction effect mainly depends on the weight and width of the roller. Light milling is suitable for the compaction of various road surfaces, cushions, airport pavement, and squares, especially for the compaction of asphalt pavement, because it can make the road surface smooth and not prone to cracks and muddying. Light milling generally adopts mechanical or hydraulic transmission, and the operation is simple and convenient.
2) Groove rollers
A grooved roller is a roller with grooves on the surface, and its compaction effect mainly depends on the weight of the roller and the depth of the groove. The grooved roller is suitable for the compaction of roadbeds, embankments, and other projects, especially the compaction of cohesive soil and clay because it can cause large deformation of the pressed layer and increase its density and strength. The grooved roller generally adopts mechanical or hydraulic transmission, and the operation is simple and convenient.
3) sheep foot rollers
The sheep foot roller is a roller with many small steel rods on its surface. Its compaction effect mainly depends on the weight of the roller and the number of steel rods. The sheep foot mill is suitable for the compaction of roadbeds, dams, and other projects, especially the compaction of loose soil and fillers because it can cause large deformation of the pressed layer and increase its density and strength. The sheep foot roller generally adopts mechanical or hydraulic transmission, and the operation is simple and convenient.
Steel-wheeled road rollers mainly use static pressure and vibration force to compact materials and are suitable for compacting materials such as sandy, semi-cohesive, and cohesive soils, stabilized soils, and asphalt concrete. The advantages of steel wheel rollers are good compaction effect and high compactness.
The static road roller is a machine that uses the principle of static compaction and uses the rollers driven by the road roller to repeatedly roll the pressed materials. The static pressure generated by the self-weight and load of the rolling wheel acts directly on the paving layer, making the solid particles of the pressed materials such as soil close to each other to form an overall structure with certain strength and stability.
The vibratory road roller uses the mechanical weight and the exciting force generated by the exciter to force the compacted material to vibrate vertically, sharply reducing the internal friction force between soil particles, making the particles closer and increasing the compactness, thereby achieving compaction. real purpose. The rolling wheel reciprocates along the surface to be compacted, and at the same time uses the exciting force generated by the rotation of the eccentric mass M (vibrating at a certain frequency and amplitude), so that the pressed layer is simultaneously subjected to the combined static pressure and vibration force of the rolling wheel. The effect is to apply a short-term continuous pulsating impact to the material.
2. Rubber-tyred road rollers
The tire roller is composed of multiple pneumatic tires, generally, there are two rows, front and rear, and each row has 3 to 5 tires. The tire-type road roller mainly uses the vertical and horizontal pressure generated by the tire to compact the material and is suitable for the compaction of the surface or middle layer of gravel, gravel mixture, asphalt concrete, and other materials.
The rubber-tired road rollers are a kind of rubbing compaction, which has a good compaction effect and can remove small cracks caused by steel wheel compaction. The rubber wheel compaction will make the mortar formed by asphalt, mineral powder, fine aggregate, etc. in the mixture float up, making the upper surface more compact and waterproof. But the rubber wheel also has disadvantages, such as easy to adhere to the mixture, leaving marks, and damaging the gradation.
To sum up, the different shapes of the wheels of road rollers are to adapt to different materials and occasions and improve compaction efficiency and quality. When selecting a road roller, the appropriate wheel shape should be selected according to the engineering needs and site conditions.