Compaction Technique Of Road Roller Road Base
Many people don't understand the compaction of the road base of the road roller. There are different things to be noted according to different road materials. Today, we will introduce the road materials of the road roller to the basic roads of the road roller. What problems should be noticed in compaction.
(1) Compaction of cement stabilized soil base
Cement stabilized soil refers to a mixture of cement and water in a loose crushed soil, which has a certain compressive strength after mixing, compaction and curing. For the road base layer paved with cement stabilized soil, the following matters should be noted when rolling:
1 When the mixture is roughly flattened on the road section, it should be quickly rolled up with a tire roller or tractor or grader and leveled.
2 After the base layer has been shaped, it is rolled in a basic width with a three-wheel smooth roller or a heavy-duty tire roller or a vibratory roller of 12t or more. In the straight section, the road shoulders should be crushed toward the center of the road; in the curved section, the inner shoulder should be crushed to the outer shoulder. When rolling, the overlap width is 1/2 of the width of the rear wheel, and the edge and shoulder of the stable layer should be pressed 2-3 times. When the water content is more than 2%, it should be crushed more than 6 times, the first two rolling times are 1.5-1.7km/h, and the next several times is 2-2.5km/h. During the rolling process, the U-turn or emergency braking shall not be performed on the finished or rolling road section to avoid damage to the surface of the base.
3 Prevent the occurrence of "spring", looseness and peeling during the rolling process, and make a small amount of water when dry.
4 In the later stage of rolling, excessive stress or long rolling time should be avoided to prevent the strength of cement stabilized soil from being reduced. At the end of the "final pressure", a roller compactor should be used to improve the flatness of the surface of the base layer.
5 It is best to use a tire roller for rolling, the machine weight is 10-20t, the tire pressure is about 0.7MPa, and the number of wheels is between 7-11.
6 When the stable soil is laid on the soft roadbed, it is better to use the vibratory roller with medium and low line pressure. When the compaction density is increased, the paving becomes hard and the roller produces a slight bounce, the amplitude should be reduced to avoid damage to the machine.
(2) Compaction of lime stabilized soil base
Lime stabilized soil refers to a mixture with a certain amount of compressive strength obtained by mixing an appropriate amount of lime and water in loose broken soil after mixing, compacting and curing. For the road base or sub-base layer with lime stabilized soil as the auxiliary material, the following matters should be noted when rolling:
1 Check the water content of the mixture before rolling. The crushing effect is best when the water content is 1%-2%, and the watering should be supplemented when the water content is insufficient. When the water content is too large, it should be turned over.
2 After artificial paving and shaping, first use a tractor, or a 6-8t tandem roller, or a tire roller to crush 1-2 times; then use a static roller compactor of 12t or more to compact until the mixture is compacted. When the degree reaches 95%-98%.
3 If lime stabilized soil is used as the base layer of high-grade pavement, the water and lime content should be accurate. When rolling, it is not possible to use a heavy-duty static roller for multiple times of rolling. Instead, a high-efficiency vibratory roller should be used. The vibration source is first disconnected for static pressure, and then the vibration is compacted gradually. Finally, the vibration source is disconnected for static compaction.
(3) Compaction of lime stabilized industrial waste residue base
Lime stabilized industrial waste is a mixture of a certain amount of lime, fly ash (or cinder) mixed with other aggregates (or no other aggregates), adding an appropriate amount of water, mixing, compacting and curing. material. Since the compactness of this mixture has a great influence on the strength, it is recommended to use a heavier roller for rolling in real time. Usually, after first pressing 3-4 times with a medium-sized roller, continue to crush 6-8 times with a heavy-duty roller until the required compactness is reached. Point me: Receive the project spree
(4) Compaction of graded aggregate base
The grading type aggregate refers to a mixture of gravel or gravel or gravel mixed in size.
For the base layer paved with such a mixture, it is preferable to use a vibratory roller for compaction, or a static roller compactor of 12 t or more, or a heavy tire roller, or a vibratory roller to be rolled together with the tire roller.
(5) Compaction of the interstitial gravel base
The interstitial gravel base layer refers to the road base layer formed by stratified and layered rolling of large, medium and small single-size gravel of different specifications.
This kind of base layer should be divided into two steps when laying: firstly laying large gravel and compacting; then laying small gravel and finally compacting. For the first compaction, 8-10t static series roller or 5t vibratory roller should be used for rapid rolling, and all the caulking materials should be vibrated into the coarse gravel pores. The second paving of the small gravel continues to be crushed with a vibratory roller. After the pores on the surface of the gravel are all filled, use a 12-15t static light roller for a final pressure of 1-2 times until the surface is flat and stable, no obvious wheel tracks, no stone creep phenomenon.