Analysis Of Road Roller Compaction Principles And Techniques
Many operators do not have a comprehensive understanding of the road roller compaction method. Now, let's popularize it with everyone. The following is the road roller compaction method. I hope it can help everyone:
Analysis of road roller compaction principles and skills
Road Roller compaction principle
Compact along the longitudinal direction of the line, and follow the principle of "first light, then heavy, slow first, then fast, first edge, then middle (curve section first inside, then outside)". It adopts static pressure 1 time + vibration 3-4 times + static pressure 1 time, and the walking speed is controlled at 3-6km / h. The specific methods are as follows:
The compacted pavement should start from the edges on both sides of the road roller and gradually roll to the center of the road. Rolling belts have to have a certain overlap width twice, the overlap width of the series road roller and the single-wheel vibratory road roller is 250 ~ 300mm, and the overlap width of the static rolling three-wheel road roller can be half of the main roller.
The best temperature to start the first impact rolling: petroleum asphalt is between 80 ~ 150 ℃. (Residue asphalt is 90 ~ 110 ℃, if the rolling temperature is too high, the material will be squeezed in front of the roller, appearing to expand along the edge of the road roller and produce lateral cracks and adhesion to the roller. When the rolling temperature is too low At this time, the viscosity of asphalt becomes high and it is difficult to compact, and cracks may appear on the pavement after rolling.
The road roller should be rolled as close as possible to the paver, and the method of applying pressure first and then lighter to ensure that the mixture meets the density requirements before it cools below the required minimum temperature.
When rolling over the newly paved asphalt mixture, the operator should first drive the drive wheel into the fresh mixture yard to reduce ripples and breakage.
Keep the impact rolling speed constant, and do not stop arbitrarily on the hot material surface; turn or start slowly, so as to minimize the indentation.
Road Roller compactor
During operation, the road roller should start before it can start to vibrate, and the internal combustion engine should be placed at medium speed and then adjusted to high speed.
When rolling downhill on a steep slope, a light roller should be used for pre-compaction, and then a heavy roller or vibratory roller should be used for compaction.
Whether it is rolling uphill or downhill, the drive wheels of the road roller should be behind. This has the following advantages: when going uphill, the rear drive wheel can withstand the driving force provided by the ramp and the machine itself, and the front wheel initially compacts the road surface to withstand the large shear force generated by the drive wheel When going downhill, the impact force generated by the roller's own weight is offset by the braking of the drive wheel. Only the mixture after the front wheel has the ability to support the rear drive wheel to generate shear force.
In the road roller compaction process, for the vibratory roller, the low frequency is used first, and then the high frequency is used. Because the amplitude of the low frequency road roller is large, it is conducive to deep layer compaction. After the roller compaction is completed, the surface of the subgrade is leveled, and a cross slope is prepared to ensure good drainage.