Road construction on the road when the road must be compacted. The compaction process of the road material is to load the pressed material to overcome the friction between the solid particles in the original loose multiphase material, the adhesion force, the removal of the gas or the liquid, so that the particles are displaced and close to each other. This material is compacted and its density is increased. The density can be expressed in terms of unit weight (for example: tons per cubic meter) Compaction of the material, generally with periodic loading. During the loading process, the stress of the material can be increased to the maximum; during unloading, the stress of the material decreases and then cycles through and stops. One of the methods of compaction: rolling, rolling is a roller with a certain weight slowly rolled through the material layer, with static pressure to be permanent deformation of the layer was. With the increase in the number of rolling, the density of the material increases, while the permanent residual deformation decreases, and finally the actual residual deformation is equal to zero. In order to further improve the density of the material being pressed, it must be rolled with heavier rollers. Compaction method of the two: tamping, tamping is the use of a large mass of large objects, from a certain height on the cycle of free fall to produce impact, the material compaction. Compaction method of the three: vibration, vibration is fixed on a certain quality of the vibrator on the high-frequency vibration generated by the pressure of the material, so that it occurs close to its inherent vibration frequency of vibration, The material has a lot of liquidity, so that particles close to increase the density, the material compaction. Rolling: the cycle of a long time, the material stress state of the change rate is not large, but the stress is greater compaction: the material produced by the stress changes a lot. In the compaction of the soil, especially for the viscous soil has a good compaction effect: the surface stress is small, the process time is short, the loading frequency is large, can be widely used in viscous materials such as sand, cement concrete In the same machine, several compaction methods can be used at the same time, so that the advantages of each compaction method can be used to improve the compaction effect - for example, the vibratory roller utilizes both compaction and compaction method. pavement model paving equipment
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