There are two factors affecting the compactness and flatness of asphalt concrete structure layer: compaction temperature and compaction method.
The compaction temperature shall be commanded and controlled by the on-site temperature testing personnel.
Key points of compaction method for the asphalt roller
- The rolling shall be carried out from top to bottom, from static to vibration, and from slow to fast. The single rolling distance shall be as long as possible to give full play to the stability of the rolling pressure;
- It is required that the road roller should closely follow the paver for rolling, and should not be too far away so as to avoid uncontrollable temperature conditions. Before final rolling, all wheel rails shall be eliminated, and the operation shall be stopped immediately after meeting the requirements to avoid excessive vibration;
- The elimination of wheel/rail can be carried out by overlapping rolling. During rolling, 1/3~1/2 of the overlapping wheel width of adjacent rolling strips will be gradually moved from the low side of the cross section to the high side, and the roller will turn back once for rolling;
- If it is not on the same section as the direction of the paver, but in a stepped shape, it is necessary to stagger the distance from front to back during each rolling, usually half a meter. The method of first long and then short is adopted, that is, the first rolling distance is long, and the later distance is gradually shortened.
- Pay attention to the amount of water sprayed by the roller nozzle, which should not stick to the wheel, and it is prohibited to turn, brake or stay until the rolling process is terminated.
Specific rolling steps of the asphalt roller
- Initial pressure
The initial rolling temperature shall be above 150 ℃. Start the machine and use the steel wheel roller to conduct static pressure for 1~2 times at a speed within 2 km/h and keep it fast. Rolling shall be carried out on the plane, with the driving wheel in the front, that is, facing the paver, and the passive wheel in the rear. In case of a ramp, the driving wheel shall be at a low position no matter whether it is uphill or downhill.
After the initial compaction is completed, the re compaction can be carried out. At this time, the temperature of the pavement shall not be lower than 125 ℃. First, use a heavy double steel wheel roller to vibrate and compact for 4 times, with a speed of 4km/h~5km/h, and then use a heavy tire roller to compact for 6 times, with a speed of 3.5km/h~4.5km/h. Finally, the rolling times can be increased by 1~2 times.
- Final pressure
The final compaction shall be carried out immediately after the re compaction is completed. At this time, the pavement temperature should be above 110 ℃. Turn off the vibration and conduct static rolling at the speed of 2km/h~3km/h.