The construction technology of impact rolling reinforcement and compaction, also known as "detectable reinforcement and compaction", refers to the construction technology of impact rolling and supplementary compaction of up to standard Subgrade after the vibratory roller compaction meets the requirements of design drawings or specifications. The purpose is to further improve the compactness and uniformity of the subgrade and reduce the post construction settlement and differential settlement.

This shows that the impact roller has a stronger compaction effect than the vibratory roller. The non-circular rolling wheels on the 3~5 sides of the impact roller make it have a large drop, which is what we call "large amplitude". At the same time, with the support of a high running speed of 10~15 km / h, it has a impact compaction capacity of up to several hundred tons.

The impact roller has no power and needs to be driven by the traction machinery for rolling construction. Due to the different specific construction requirements, some construction sections with small paving thickness, especially the construction sections with impact rolling reinforcement and compaction technology, can be rolled by a smaller model of impact roller pulled by a loader.

Next, let's talk about the matters needing attention when using the loader to pull the impact roller?

Let's first watch a video of the impact roller's impact rolling construction. We can see that after the loader drags the impact roller to the construction station, it slowly puts down the impact roller, then starts to drag, and then starts to accelerate, increasing the impact rolling speed to more than 10 km / h.

In this link, we need to pay attention to two points:

1、 Pay attention to retracting the lifting cylinder of the impact roller in place;

After the loader drags the impact roller to the construction station and slowly puts down the impact roller, it is necessary to pay attention to retract the lift cylinder of the impact roller in place to avoid that the lift cylinder still in the lifting state bears the impact force during the construction of impact roller, which will cause damage to the cylinder or other parts, and weaken the impact roller effect.

Many people believe that in this case, do not lift the oil cylinder. This understanding is wrong. The lifting cylinder of the impact roller has the functions of lifting, beam tube and buffer at the same time (see the relevant specific introduction). If you are worried about misoperation, you can not use it, but it is not recommended to abandon this configuration.

2、 Try to increase the impact rolling speed to more than 10 km / h;

In addition to the poor corners of the non-circular roller wheels on the 3~5 sides, that is, what we call "large amplitude" brings greater impact tamping strength. The speed addition is also an important factor for the huge impact force of the impact roller. In addition to the sufficient power output of the traction machinery, the hydraulic buffer speed increase system is also very important for the speed increase of the impact roller.

The hydraulic buffer speed increasing system of the impact roller can adjust the uneven running speed of the impact roller "one impact one impact", decelerate at high speed and increase at low speed, so that its running speed is closer to the "uniform speed" to a greater extent, which is conducive to the speed increase of the equipment and the protection of the equipment and traction machinery.

As for the configuration of the hydraulic buffer speed increasing system of the impact roller, we can make a general judgment by the appearance of the impact roller. Generally, the impact roller of the hydraulic buffer speed increasing system retains the frame cover (see the figure), while most of the others are sealed (see the figure).

In addition to the lack of power, the product performance of the impact roller tractor, which is not professionally designed by the loader, also has different emphasis. For example, the speed ratio of its gearbox and drive axle is not fully applicable to the harsh construction conditions of the impact roller. Moreover, its traction height is not necessarily matched with the impact roller.

3、 Note that the traction height of loader and impact roller shall match;

The non-circular cam structure on the 3~5 sides of the impact roller makes its working center of gravity of the impact roller jump up and down within a certain range during operation. If the traction height does not match, high or low, part of the impact force will act on the traction frame, which will not only make the loader or impact roller passively stressed, and then damaged, but also weaken the compaction effect on the foundation.

We know that the traction height of loaders produced by different loader manufacturers or different models of loaders is different. If the traction height of loaders does not match the traction height of impact rollers, it is necessary to modify the traction position of loaders. There are also some requirements for refitting the traction of loaders, which are introduced in detail in relevant articles.

4、 Pay attention to adjusting the reasonable speed and turning speed;

The impact roller has a rolling speed requirement of 10~15 km / h for impact rolling construction. Generally, the higher the speed, the better the impact rolling effect. The loader is used for traction. Although all the impact rollers are small models, the power is still slightly insufficient, so there is no need to worry about speeding.

However, it should still be noted that the speed of impacting and crushing asphalt and concrete pavement should be controlled within the range of 8~12km/h, and at the same time, attention should be paid to controlling the safe construction speed. When the impact roller turns around or is close to the groove and structure, the speed should not exceed 8km/h, especially in the downhill section, the high speed has great potential safety hazards in these cases.

5、 The turning radius of the loader traction impact roller shall be large;

The impact roller cannot turn small turns, which is determined by the construction characteristics of the impact roller. In order to ensure the impact rolling effect, the two non-circular rolling wheels of the impact roller must be synchronized, so that the impact roller can not use the differential device as conventional vehicles, but use a synchronous through shaft.

Most of the existing impact roller tractors belong to the pre power device design, that is, the engine, gearbox and other devices are in front, and the steering is hinged at the rear. In this way, the traction impact roller is not only stable, but also has a better turning. Generally, the turning radius (outside) is required to be about 5.8 meters.

The loader has a long body (plus bucket) and is also a rear mounted design of the power unit, that is, the engine, gearbox and other devices are at the back and are directly connected with the impact roller. On the whole, the front is light and the rear is heavy. Therefore, in addition to paying attention to turning deceleration, the turning radius should be appropriately increased.

6、 Pay attention to check the brake system of the loader.

Due to the high rolling speed of the impact roller and the huge inertia of the non-circular roller, the impact roller tractor is usually equipped with two air bags (except for individual loader modified vehicles), so as to enhance the construction safety. Since the loader is light, pay special attention to the use of caliper disc brake and brake pedal.

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