JP6952009B2 - Roadbed improvement method - Google Patents

Description

The present invention relates to a roadbed improvement method.

A roadbed improvement method for constructing a new stable-treated roadbed by crushing an existing asphalt pavement and mixing an existing roadbed material and a stabilizer is known (see, for example, Patent Document 1). The roadbed improvement method is classified according to the type of stabilizer used, and typical examples include a cement stabilization method, a lime stabilization method, an asphalt emulsion stabilization method, and a foamed asphalt stabilization method. ..

The cement stabilization method is a method of improving the roadbed by using powdered cement as a stabilizer and mixing the existing roadbed material and cement. The lime stabilization method is a method of improving the roadbed by using powdered lime as a stabilizer and mixing the existing roadbed material and lime. The asphalt emulsion stabilization treatment method is a method of improving the roadbed by using a liquid asphalt emulsion as a stabilizer and mixing the existing roadbed material and the asphalt emulsion. The foamed asphalt stabilization method is a method of improving the roadbed by using foamy foamed asphalt as a stabilizer and mixing the existing roadbed material and foamed asphalt.

Japanese Unexamined Patent Publication No. 2003-301410

However, in the cement stabilization method and the lime stabilization method, there is a high possibility that hexavalent chromium will elute in the process of mixing the existing roadbed material with cement or lime, which poses a problem in terms of environmental load. Further, the cement stabilization method and the lime stabilization method have a problem that cracks are likely to occur due to drying shrinkage. In addition, the cement stabilization method and the lime stabilization method require curing after construction, which makes it difficult to open traffic at an early stage.

In the asphalt emulsion stabilization method, the strength may be insufficient due to the influence of the emulsifier remaining in the asphalt and the water that could not be completely removed.
Since the foamed asphalt stabilization method requires an asphalt lorry, a sprinkler, etc., there is a problem that the machine formation becomes large and it becomes difficult to open the traffic at an early stage. As a result, large-scale traffic regulation is required, which causes a problem that the labor and cost for safety measures increase.

The present invention has been devised from such a viewpoint, and an object of the present invention is to provide a roadbed improvement method excellent in reduction of environmental load, strength of improved roadbed, flexibility of improved roadbed, and early openness.

In order to solve the above problems, the present invention is a roadbed improvement method for improving an existing roadbed, in which a supply step of supplying a newly heated asphalt mixture as a stabilizer and the newly heated asphalt mixture are laid on the existing roadbed. It is characterized by including a spreading step of spreading and a crushing and mixing step of crushing the existing roadbed and mixing the existing roadbed material and the newly heated asphalt mixture.

According to this method, by using a newly heated asphalt mixture as a stabilizer, hexavalent chromium does not elute, so that the environmental load can be reduced. Further, by mixing the newly heated asphalt mixture with the existing roadbed material, the strength of the improved roadbed can be increased and the flexibility of the improved roadbed can also be improved. Since it has excellent flexibility, it is possible to suppress the occurrence of cracks. In addition, by using a newly heated asphalt mixture as a stabilizer, curing after construction becomes unnecessary and the mechanical knitting can be reduced, so that traffic can be opened at an early stage.

Further, it is a roadbed improvement method for improving the existing roadbed by assembling a machine including at least a pavement device. The pavement device supplies a travelable vehicle body and the new heated asphalt mixture on the existing roadbed. A traction type crushing and mixing device for crushing the existing roadbed and mixing the existing roadbed material and the newly heated asphalt mixture. Is preferable.
According to such a construction method, a supply device, a spreading device, and a traction type crushing / mixing device are mounted on one vehicle body. As a result, the self-propelled stabilizer does not run on the newly heated asphalt mixture spread by the spreading device, so that the newly heated asphalt mixture does not adhere to the tracks and wheels of the stabilizer. Further, since the spreading device and the crushing / mixing device are mounted on one vehicle body, the distance between the spreading / spreading device and the crushing / mixing device can be shortened, and the time from spreading to mixing can be shortened. As a result, the temperature drop of the newly heated asphalt mixture can be suppressed and the newly heated asphalt mixture and the existing roadbed material can be mixed while the temperature is high, so that the quality of the improved roadbed can be improved.

According to the present invention, it is possible to provide a roadbed improvement method excellent in reduction of environmental load, strength of improved roadbed, flexibility of improved roadbed, and early openness.

It is a side view which shows the pavement apparatus which concerns on 1st Embodiment of this invention. It is a side view which shows the cutting process of the roadbed improvement construction method which concerns on 1st Embodiment. It is a side view which shows the secondary cutting process of the roadbed improvement construction method which concerns on 1st Embodiment. It is a side view which shows the supply process, the spread spread process, and the crushing mixture process of the roadbed improvement method which concerns on 1st Embodiment. It is a side view which shows the roadbed correction process of the roadbed improvement construction method which concerns on 1st Embodiment. It is a side view which shows the roadbed finishing process of the roadbed improvement construction method which concerns on 1st Embodiment. It is a side view which shows the cutting process of the roadbed improvement method which concerns on 2nd Embodiment. It is a side view which shows the supply process, the spread spread process, and the crushing mixture process of the roadbed improvement method which concerns on 2nd Embodiment. It is a side view which shows the roadbed correction process of the roadbed improvement construction method which concerns on 2nd Embodiment. It is a side view which shows the roadbed finishing process of the roadbed improvement construction method which concerns on 2nd Embodiment.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the present embodiment, a case where the pavement device of the present invention is applied to an asphalt finisher will be described as an example. In the description, "front and back" and "up and down" are based on the vehicle body front and rear direction and the vehicle body up and down direction, and "left and right" are based on the left and right direction (vehicle width direction) as seen from the driver's seat.

As shown in FIG. 1, the asphalt finisher (paving device) A mainly includes a self-propelled vehicle body 1, a hopper 2, a transport device 3, a spreading device 4, and a towed stabilizer 5. I have. In the present embodiment, the stabilizer 5 is mounted in place of the screed device behind the vehicle body of the asphalt finisher A.

Although the vehicle body 1 uses a track-type traveling vehicle in the present embodiment, a tire-type traveling vehicle may be used. The vehicle body 1 includes a vehicle body frame, a pair of left and right tracks 1a (only one side is shown), an engine room 1b, a driver's seat 1c, and the like. The front portion of the track 1a is arranged below the hopper 2. The rear part of the track 1a is arranged below the engine room 1b and the driver's seat 1c.

The hopper 2 is a member that receives and stores a stabilizer from a dump truck during pavement construction. As the stabilizer, a freshly heated asphalt mixture is used. The hopper 2 is arranged at the front portion of the vehicle body 1. The hopper 2 is arranged in front of the engine room 1b and the driver's seat 1c.

The transport device (supply device) 3 is a device that transports the newly heated asphalt mixture in the hopper 2 to the rear and supplies it onto the existing roadbed R1. The transport device 3 extends rearward from the lower position of the hopper 2 between the left and right tracks 1a. The rear end portion 3a of the transport device 3 constitutes a carry-out end and is located in front of the spreading device 4. The transport device 3 is not particularly limited as long as it has heat resistance capable of transporting a newly heated asphalt mixture, but for example, a bar feeder type conveyor or a screw type conveyor is preferably used.

The spreading device 4 is composed of a screw spreader that spreads the newly heated asphalt mixture supplied on the existing roadbed R1 in the vehicle width direction. The spreading device 4 is arranged behind the crawler belt 1a in the rear part of the vehicle body 1. The spreading device 4 includes a screw extending in the vehicle width direction. The screws are rotatably arranged around an axis along the vehicle width direction.

The stabilizer (crushing and mixing device) 5 is a device that crushes the existing roadbed R1 and mixes the existing roadbed material and the newly heated asphalt mixture. The stabilizer 5 is attached to a leveling arm 6 (only one side is shown) extending rearward from both side surfaces of the vehicle body 1, and is arranged further behind the spreading device 4. The stabilizer 5 is extended in the vehicle width direction. When adjusting the crushing depth of the existing roadbed R1, the leveling arm 6 may be operated to adjust the height of the stabilizer 5. Further, when the stabilizer 5 is not crushed and mixed, the stabilizer 5 can be prevented from coming into contact with the road surface by raising the stabilizer 5.

The stabilizer 5 is a traction type device that moves as the asphalt finisher A travels. The stabilizer 5 uses a rotor drum type in this embodiment, but may be a chain type or the like. The stabilizer 5 mainly includes a pair of left and right arms 51 (only one side is shown), a rotor drum 52, and a hood 53.

The arm 51 is a metal member for attaching the hood 53 and the rotor drum 52 to the vehicle body 1. The base end portion of the arm 51 is rotatably connected to the leveling arm 6. The tip of the arm 51 is connected to the hood 53 and the rotor drum 52. One arm 51 is arranged on each of the left and right sides of the hood 53 and the rotor drum 52. The shape of the arm 51 is not particularly limited, but in the present embodiment, it exhibits an oval shape in a side view. The arm 51 is inclined downward toward the rear.

The rotor drum 52 includes a rotating shaft 52a extending in the vehicle width direction, a rotor drum main body 52b rotatably supported by the rotating shaft 52a, and a plurality of teeth 52c attached to the outer peripheral surface of the rotor drum main body 52b. ing. The rotation direction of the rotor drum 52 is set to be opposite to the rotation direction of the track band 1a.

The rotation shaft 52a is a metal member that serves as the rotation center of the rotor drum 52, and has a columnar shape. The left and right ends of the rotating shaft 52a are rotatably supported by the left and right arms 51. The rotating shaft 52a penetrates the center of the rotor drum body 52b to the left and right. Although not shown, a driving means such as a motor for rotating the rotor drum 52 is connected to the rotating shaft 52a via a driving transmission mechanism such as a chain or a belt. The power required for the rotation of the rotor drum 52 may be obtained from the residual oil pressure of the existing asphalt finisher A, another engine mounted on the stabilizer 5, or the like.

The rotor drum main body 52b is a metal member that rotates with the rotation of the rotating shaft 52a. The rotor drum body 52b has a columnar or cylindrical shape extending in the vehicle width direction.

The tooth 52c is a member that enters the existing roadbed R1 and crushes the existing roadbed R1. The tooth 52c is not particularly limited as long as the existing roadbed R1 can be crushed, but is composed of, for example, a bit or a tine. The plurality of teeth 52c are arranged side by side at intervals in the circumferential direction and the width direction of the rotor drum main body 52b.

The hood 53 is a metal member that covers the upper half of the rotor drum body 52b, and has a substantially semi-cylindrical shape that opens downward. In other words, the lower half of the rotor drum body 52b is exposed from the lower end opening of the hood 53. The hood 53 includes a pair of side walls 53a (only one side is shown) that covers the left and right sides of the rotor drum main body 52b, and the rotation shaft 52a penetrates the pair of side walls 53a to the left and right. The side wall 53a of the hood 53 is fixed to the left and right arms 51 by welding, bolts, or the like. In the stabilizer 5, the existing roadbed R1 is crushed by the teeth 52c while rotating the rotating shaft 52a and the rotor drum body 52b by the driving force of the driving means, and the existing roadbed material and the newly heated asphalt are crushed between the rotor drum body 52b and the hood 53. Mix with the mixture.

The asphalt finisher A according to the present embodiment is basically configured as described above. Next, a method of improving the existing roadbed R1 by using the asphalt finisher A according to the present embodiment will be described mainly with reference to FIGS. 2A-2E. In the roadbed improvement method according to the present embodiment, a cutting step, a secondary cutting step, a supply step, a spreading step, a crushing and mixing step, a roadbed straightening step, and a roadbed finishing step are performed.

In this embodiment, from the front side in the construction direction, the dump truck 100, the cutting machine 110, the dump truck 120, the cutting machine 130, the dump truck 140, the asphalt finisher A, the motor grader 150, the vibrating roller 160, the dump truck 170, and the cutting machine 180. A case where the existing roadbed R1 is improved by assembling the mechanical knitting in order will be described. The construction organization is not limited to the one shown in the figure.

The cutting step shown in FIG. 2A is a step of cutting the surface layer portion and the base layer portion of the existing asphalt pavement. In the cutting step, the surface layer portion and the base layer portion of the existing asphalt pavement are cut by the cutting machine 110 while the dump truck 100 and the cutting machine 110 are both running. The cutting depth may be set as appropriate, but in the present embodiment, it is set to 40 to 100 mm. The cut existing asphalt material is conveyed to the dump truck 100 in front by the conveying device 110a attached to the cutting machine 110.

The secondary cutting step shown in FIG. 2B is a step of cutting a part (surplus) of the existing roadbed R1. In the secondary cutting step, a part of the existing roadbed R1 is cut by the cutting machine 130 while the dump truck 120 and the cutting machine 130 are both running. The cut existing roadbed material is transported to the dump truck 120 in front by the transport device 130a attached to the cutting machine 130. The secondary cutting step may be omitted.

The supply step shown in FIG. 2C is a step of supplying a new heated asphalt mixture onto the existing roadbed R1. In the supply process, while the dump truck 140 and the asphalt finisher A are running together, the newly heated asphalt mixture charged from the dump truck 140 into the hopper 2 is conveyed rearward by the transfer device 3 (see FIG. 1) to the rear end portion. A new heated asphalt mixture is poured onto the existing roadbed R1 from 3a. The supply amount of the newly heated asphalt mixture per unit area can be adjusted by changing, for example, the transport speed of the transport device 3 or the traveling speed of the asphalt finisher A.

The spreading step shown in FIG. 2C is a step of spreading a new heated asphalt mixture. In the spreading step, the new heated asphalt mixture supplied on the existing roadbed R1 by the spreading device 4 of the asphalt finisher A is spread while the dump truck 140 and the asphalt finisher A are running together.

The crushing and mixing step shown in FIG. 2C is a step of crushing the existing roadbed R1 and mixing the existing roadbed material and the newly heated asphalt mixture. In the crushing and mixing step, the existing roadbed R1 is crushed by the stabilizer 5 of the asphalt finisher A while the dump truck 140 and the asphalt finisher A are running together, and the existing roadbed material and the newly heated asphalt mixture are mixed. Specifically, in the crushing and mixing step, the rotating shaft 52a and the rotor drum main body 52b shown in FIG. 1 are rotated by the driving force of the driving means, and the existing roadbed R1 is crushed by the teeth 52c. The crushed existing roadbed material is rolled up together with the newly heated asphalt mixture and taken into the hood 53 from the front side of the lower end opening of the hood 53. The existing roadbed material and the newly heated asphalt mixture taken into the hood 53 move along the rotation direction of the rotor drum body 52b while being mixed between the rotor drum body 52b and the hood 53, and the lower end opening of the hood 53 is opened. It is discharged downward from the rear side. The feeding process, the spreading process, and the crushing and mixing process are performed by a common asphalt finisher A.

The roadbed normalizing and rolling compaction step shown in FIG. 2D is a step of straightening and rolling the improved roadbed R2 containing the existing roadbed material and the newly heated asphalt mixture. In the roadbed leveling normal rolling step, the improved roadbed R2 is leveled by the motor grader 150 and the improved roadbed R2 is rolled by the vibrating roller 160 while both the motor grader 150 and the vibrating roller 160 are running.

The roadbed finishing step shown in FIG. 2E is a step of cutting and finishing the roadbed surface of the improved roadbed R2. In the roadbed finishing process, the roadbed surface of the improved roadbed R2 is cut by the cutting machine 180 while the dump truck 170 and the cutting machine 180 are both running. The cut improved roadbed material is transported to the dump truck 170 in front by the transport device 180a attached to the cutting machine 180. The total amount of cutting depth in the secondary cutting process and roadbed finishing process and the supply amount of the newly heated asphalt mixture in the supply process are such that the layer thickness of the improved roadbed R2 after the roadbed finishing process is the same as that of the existing roadbed R1 before the secondary cutting process. It is preferable to set the thickness to be substantially the same as the layer thickness.

Next, the action and effect of this embodiment will be described.

According to this embodiment, by using a newly heated asphalt mixture as a stabilizer, hexavalent chromium does not elute, so that the environmental load can be reduced. Further, by mixing the newly heated asphalt mixture with the existing roadbed material, the strength of the improved roadbed R2 can be increased, and the flexibility of the improved roadbed R2 can also be improved. Since it has excellent flexibility, it is possible to suppress the occurrence of cracks. In addition, by using a newly heated asphalt mixture as a stabilizer, curing after construction becomes unnecessary and the mechanical knitting can be reduced, so that traffic can be opened at an early stage.

Further, according to the present embodiment, by mounting the stabilizer 5 on the asphalt finisher A specialized for spreading the asphalt mixture, the stabilizer 5 supplies an appropriate amount of the newly heated asphalt mixture while the asphalt finisher A supplies an appropriate amount. Since the newly heated asphalt mixture and the existing roadbed material can be mixed, the quality of the improved roadbed R2 can be improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be appropriately modified without departing from the spirit of the present invention.
In the first embodiment, the towed stabilizer 5 is mounted on the existing asphalt finisher A instead of the screed device. For example, a new paved vehicle equipped with the transport device 3, the spreading device 4, and the towed stabilizer 5. May be manufactured and used for roadbed improvement.

<Second embodiment>
Next, the second embodiment of the present invention will be described. As shown in FIGS. 3A-3D, the second embodiment is different from the first embodiment in that the asphalt finisher 190 is not equipped with the towed stabilizer 5 and the self-propelled stabilizer 200 is used to improve the roadbed. do. In the second embodiment, the differences from the first embodiment will be mainly described.

The asphalt finisher 190 shown in FIG. 3B mainly includes a vehicle body 190a, a hopper 190b, a transport device (not shown), a spreading device 190c, and a leveling arm 190d. The configuration of the vehicle body 190a and the like is the same as that of the first embodiment. A screed device 190e for spreading a new heated asphalt mixture is attached to the leveling arm 190d of the present embodiment.

The stabilizer 200 shown in FIG. 3B mainly includes a self-propelled vehicle body 200a, a pair of left and right arms 200b (only one side is shown), a rotor drum 200c, and a hood 200d. The configuration of the arm 200b, the rotor drum 200c, and the hood 200d is the same as that of the first embodiment.

The roadbed improvement method according to the second embodiment includes a cutting process by the dump truck 100 and the cutting machine 110 shown in FIG. 3A, a supply process and a spreading process by the dump truck 140 and the asphalt finisher 190 shown in FIG. 3B, and a stabilizer 200. The crushing and mixing step, the roadbed adjusting step by the motor grader 150 and the vibrating roller 160 shown in FIG. 3C, and the roadbed finishing step by the dump truck 170 and the cutting machine 180 shown in FIG. 3D are performed. The secondary cutting step of the first embodiment may be performed. Since the cutting step, the roadbed straightening step, and the roadbed finishing step of the second embodiment are the same as those of the first embodiment, the description thereof will be omitted.

As shown in FIG. 3B, in the supply process, the spreading process, and the crushing and mixing process, the dump truck 140, the asphalt finisher 190, and the self-propelled stabilizer 200 are mechanically organized in this order from the front side in the construction direction. In the supply step, the spreading step, and the crushing and mixing step, the dump truck 140, the asphalt finisher 190, and the self-propelled stabilizer 200 are running together, and the newly heated asphalt mixture charged from the dump truck 140 into the hopper 190b is transferred by the transport device. It is transported to the rear, and a new heated asphalt mixture is charged onto the existing roadbed R1 from the rear end of the transport device. Subsequently, after spreading the newly heated asphalt mixture supplied on the existing roadbed R1 by the spreading device 190c of the asphalt finisher 190, the existing roadbed R1 is crushed by the self-propelled stabilizer 200 to make a new roadbed material. Mix with the heated asphalt mixture.

Also in the second embodiment described above, the effect of using the newly heated asphalt mixture as the stabilizer can be obtained as in the first embodiment.
However, in the roadbed improvement method of the second embodiment, since the subsequent stabilizer 200 runs on the newly heated asphalt mixture spread by the asphalt finisher 190, the newly heated asphalt mixture adheres to the tracks and wheels of the stabilizer 200. There is a risk. Further, since the asphalt finisher 190 is used for the spreading work and then the stabilizer 200 is used for the mixing work, it takes time from the spreading to the mixing. This causes the temperature of the newly heated asphalt mixture to be lowered by the outside air, and the quality of the improved roadbed R2 may be deteriorated because the newly heated asphalt mixture whose temperature has been lowered is mixed with the existing roadbed material. In this regard, according to the first embodiment, as shown in FIG. 1, a transport device 3, a spreading device 4, and a traction type stabilizer 5 are mounted on one vehicle main body 1. As a result, the self-propelled stabilizer does not run on the newly heated asphalt mixture spread by the spreading device 4, so that the newly heated asphalt mixture does not adhere to the tracks and wheels of the stabilizer. Further, since the spreading device 4 and the stabilizer 5 are mounted on one vehicle main body 1, the distance between the spreading device 4 and the stabilizer 5 is shortened as compared with the roadbed improvement method of the second embodiment. The time from to mixing can be shortened. As a result, the temperature drop of the newly heated asphalt mixture can be suppressed and the newly heated asphalt mixture and the existing roadbed material can be mixed while the temperature is high, so that the quality of the improved roadbed R2 can be improved.

Further, according to the first embodiment, by mounting the towable stabilizer 5 on the asphalt finisher A, one paved vehicle has a supply function, a spreading function, and a crushing and mixing function. Therefore, the second embodiment. Compared with the case where two paved vehicles are used separately for the asphalt finisher 190 and the stabilizer 200 as described above, the number of paved vehicles can be reduced by one and the machine formation can be simplified. As a result, the labor and cost spent on safety measures during construction can be reduced, and the construction period can be significantly shortened.

A Asphalt finisher (paving equipment)
1 Vehicle body 2 Hopper 3 Transport device (supply device)
4 Spreading device 5 Stabilizer (crushing and mixing device)
R1 existing roadbed R2 improved roadbed

Claims (2)

It is a roadbed improvement method to improve the existing roadbed.
A supply process for supplying a new heated asphalt mixture as a stabilizer on the existing roadbed, and
The spreading process of spreading the new heated asphalt mixture with a screw spreader, and
A crushing and mixing step of crushing the existing roadbed and mixing the existing roadbed material and the newly heated asphalt mixture.
A roadbed improvement method characterized by including. A road machine improved method you improve the assembly seen already設路Release mechanical organize paving device contains at least,
A supply process for supplying a new heated asphalt mixture as a stabilizer on the existing roadbed, and
The spreading step of spreading the newly heated asphalt mixture and spreading
A crushing and mixing step of crushing the existing roadbed and mixing the existing roadbed material and the newly heated asphalt mixture is included.
The pavement device crushes the travelable vehicle body, the supply device for supplying the newly heated asphalt mixture on the existing roadbed, the spreading device for spreading the newly heated asphalt mixture, and the existing roadbed. A roadbed improvement method comprising a traction type crushing and mixing device for mixing the existing roadbed material and the newly heated asphalt mixture.

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