JPH03206201A - Method and machine for paving road with rolled concrete - Google Patents

Abstract

PURPOSE:To improve the adhesion of upper and lower pavement by uniformly laying and compacting a paving material of a lower layer portion, and further laying and compacting thereon a paving material of a upper layer portion after scarifying the compacted surface. CONSTITUTION:After a paving material is dropped onto a road foundation F through a feeder from a hopper 2 of a paving machine B to be spread by a screw spreader 3, a lower layer portion h1 is formed by uniformly laying and compacting the paving material with a screed 4. Next, the compacted surface of the lower layer portion h1 is scarified by a scarifier provided in front of the spreader 3. Then, a paving material of an upper layer portion h2 is laid and compacted on the compacted surface of the lower layer portion h1 to form a paving layer H. Further, after secondarily rolling the upper surface of the paving material H with a vibrating roller C, the pavement is finished with a finishing roller D.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is a method of rolling concrete pavement, commonly known as roller compacted concrete pavement, in which cement concrete of cemented carbide is leveled with an asphalt finisher and then compacted with a roller.
Compacted Concrete Pavem
ent: Below 1? This article concerns a pavement construction method called ccP (abbreviated as ccP) and its paving machines.

In particular, the RCCP construction method is suitable for expressways and general roads with heavy traffic of large vehicles, where the pavement is divided into a lower layer and an upper layer, requiring a pavement thickness of 25 cm or more. , concerning the paving machine.

[Conventional technology]

As is well known, RCCP is a method of paving by leveling cemented carbide concrete and compacting it by rolling compaction, so construction speed is fast, construction period is shortened, and construction costs can be reduced. It has characteristics such as low drying shrinkage and the ability to increase joint spacing. Therefore, it is widely used for expressways and general roads, including parking areas and other ancillary facilities, as well as for paving inside premises and factory yards.

[Problem to be solved by the invention] By the way, the thickness of concrete pavement is standardized depending on the traffic volume.
Roads with more than 1,000 vehicles and fewer than 3,000 vehicles (in one direction) are about to be regulated so that they must be 25 cm or more thick.

Therefore, when the RCCP is applied to roads with a pavement thickness of 25 cm or more and other yard pavements, the following problems arise.

Firstly, the existing asphalt finisher has a structure in which, due to its mechanical limitations, it is not possible to level the thickness of 25 cm or more, including the consolidation allowance, at one time. The second point is that when the leveling thickness becomes thicker, the effects of rolling and compaction do not spread to the lower layer, making it impossible to achieve the specified degree of compaction and compressive/flexural strength for road pavement. .

Third, if the leveling thickness is increased, it is difficult to obtain good flatness, which is an important condition for roads. There were problems with the above three points.

Therefore, the present invention was developed for the purpose of providing an RCCP construction method and a pavement covering machine that solves the technical problems in pavement caused by the thickness of the pavement.

[Means to solve the problem]

As a means to achieve the above object, this invention takes the following measures.

First, we adopted a step paving method that divided the pavement into two layers, a lower layer and an upper layer, depending on the pavement thickness. That is, first, the paving material for the lower layer is leveled and compacted. Next, the compacted surface of the lower layer was loosened 1 to 23 times, and then the upper layer of paving material was leveled, compacted, and rolled to pave it. The reason is that the pavement is paved using the so-called two-layer method. Furthermore, the paving machine that performs construction work using the two-layer method includes a hopper that stores the paving material, a feeder that drops the paving material from this hopper onto the roadbed at the rear, and a feeder that drops the paving material onto the roadbed with a predetermined width. A paving machine equipped with a screed spreader that spreads the paving material evenly and a screed that spreads the spread paving material to a predetermined thickness and hardens it.
The scarifier is installed in front of the screw spreader of the paving machine so that its level in the vertical direction can be adjusted freely, and it can be attached to and detached from the machine body. That is, when paving the cemented carbide concrete for the upper layer, it is already leveled by the scarifier,
It is possible to loosen the compacted surface of the lower layer that is being compacted, spread the paving material that will become the upper layer, that is, cement concrete, and perform rolling compaction at the same time. It is characterized by being structured as follows. In addition, the scarifiers are arranged in two rows at the front and rear positions to allow the compacted surface to be thoroughly and uniformly loosened, and guide plates shaped like skis are attached to both the left and right ends of the scarifiers. The reason is that the scarifier is designed to move parallel to the compaction surface of the lower layer.

(Function) According to this invention, the lower layer part and the upper layer part are divided into two layers according to the thickness of the pavement, and the construction is carried out in two layers. RCCP can now be applied to roads that require a thickness of 25 cm or more.Moreover, after compacting the lower layer,
The compacted surface is loosened with a scarifier, and the upper layer paving material is spread on top of it and compacted by rolling, so the lower layer and the upper layer are well joined, creating an integrated radius.
It now functions as a CCP.

In addition, as a means of loosening the compacted surface after compacting the lower layer, a scarifier is installed in front of the asphalt finisher, that is, the screw spreader on the aircraft side, and this scarifier is used to loosen the surface of the lower layer. Because of the structure, the scraping is done evenly,
Moreover, it is done efficiently.

As a result, the upper layer of cemented carbide paving material, which was leveled, rolled and compacted, became more strongly bonded, and the construction work as a whole could be carried out more efficiently and quickly.

Furthermore, the scarifier that performs the scraping work is installed in front of the screw spreader in the asphalt finisher so that the level can be adjusted, and it is also detachably installed on the side of the machine that guards the finisher. At the stage of leveling, remove it from the machine or raise it above the leveling surface of the lower layer, and then pull it down when paving the upper layer.
I was able to achieve my intended purpose simply by adjusting it to the appropriate level and setting it so that I could scrape the surface of the lower layer. In addition, when the amount of construction is large, it is also possible to use two finishers, with the front finisher not equipped with the scarifier and the rear finisher equipped with a scarifier installed.

〔Example〕

Figure 1 shows an example of the organization of paving machines that carry out paving work at RCCP. 1 shows a paving machine according to the invention;

Note that C is a vibrating roller that secondarily rolls the pavement layer H that has been leveled and compacted by the paving machine B, D is a finishing roll roller, and F is a paved roadbed.

The paving machine B of the present invention has a self-propelled vehicle body 1 as shown in FIG.
Although it is not shown on the drawing, there is a hopper 2 in front of which is loaded with cemented cement concrete, which is a paving material.
The paving material is transferred from this hopper 2 to the rear roadbed F of the self-propelled vehicle body 1.
A feeder for dropping the paving material upward, a screw spreader 3 for pushing and spreading the dropped paving material uniformly in the width direction on the roadbed F, and a screw spreader 3 for spreading the pushed and spread paving material uniformly to a predetermined thickness. It also has a screed 4 for compaction.

FIG. 2 is a side view showing the mechanical parts of the screw spreader 3 and the screed 4. In this embodiment, in order to perform precise leveling and strong compaction, it is commonly called a high power compaction screed. It uses what is called a screed 4.

That is, a high-power compaction screed is equipped with a tamper 4a as the head, followed by a first pie break (vibratory compaction device) 4b, a double type pressure bar 40, and finally a second pie brator 4d.

In front of the screw spreader 3, there is a compacted surface 1 of the lower layer h+ which has been completely paved, leveled and compacted.
It is equipped with Scarifier E to loosen the 1. Note that the present invention is not limited to being installed only on finishers equipped with such a hiver conversion screed, but may also be installed on ordinary tamper, vibration type, and finishers.

FIG. 3 is a perspective view showing the schematic structure of this scarifier E. In the embodiment, as shown in the figure, cutters 22 are attached to a horizontal rod 21 at a constant pitch, and a fork-shaped cutter is used. The arms 23 and 23 that project upward toward both the left and right ends of the horizontal rod 21 are attached to the scarifier E itself in front of the screw spreader 3 on the lower surface of the paving machine B shown in FIG. This is a so-called mounting arm for numbering.

In addition, ski-shaped guide plates 24 and 24, which are also attached to the left end of the horizontal rod 2l, are used to maintain the scraping depth by the cutter 22 at a constant level, as shown in FIG. It is constructed so that it can slide and move on the compaction surface 11 of the lower layer portion h, which has been compacted.

25 shows the installation height adjustment odor of Scarifier E on the self-propelled vehicle body l side.

Although not shown in the drawing, in order to more precisely and uniformly loosen the compacted surface 11 of the lower layer h, the cutters 22 may be assembled in two rows in parallel in the front-rear direction. . In that case, the positions of the cutters 22 in the front row and the positions of the cutters 22 in the rear row are shifted from each other.

Since the construction method of roller compacted concrete pavement according to the present invention and its paving machine are exactly as explained in the examples above, the following effects not seen in conventional concrete pavement can be achieved. Ru.

〔Effect of the invention〕

(1) Since the paving method is divided into two layers, upper and lower, the thickness is 2, which was previously impossible to apply with roller compacted concrete pavement.
Can pave expressways, general roads, and factory yards with heavy traffic of 5 cm or more.

(2) After compaction and rolling of the lower layer, the surface was scraped up with a scarifier and the upper layer pavement was constructed on top of that, resulting in high bondability between the upper and lower pavements. Therefore, even though it is a two-layer pavement system, it is integrated and there is no decrease in the strength of the finished pavement. Therefore, it is ideal for paving roads that have a high traffic volume of large vehicles.

By the way, Table 1l below shows the construction method of the present invention, that is, a two-layer pavement structure (implemented) in which the compacted surface of the lower layer is scraped off, the plowing material of the upper layer is leveled, and compacted and rolled. Example), without loosening the compacted surface of the lower layer,
The results of a test conducted to confirm the adhesion strength of each adhesive interface of a simple two-layer pavement structure (Comparative Example-1) in which the upper layer of paving material was spread, compacted, and rolled are shown. It is something.

Table 1 ■ Adhesive strength of adhesive interface As shown in Table 1 above, when the compacted surface of the lower layer is loosened, the upper layer of paving material is leveled and compacted, the joint interface, that is, the adhesive interface The adhesion strength was confirmed to be about three times that of a case where a two-layer structure was simply formed without loosening.

Further, in the examples, there was no breakage at the boundary between the lower layer portion and the upper layer portion during the test, and most of the breaks occurred from the upper half portion of the upper layer portion.

On the other hand, in the case of Comparative Example-1, all the pieces were broken at the boundary between the lower layer portion and the upper layer portion. The above results demonstrate that the pavement structure of the present invention, in which the surface of the lower layer is leveled and the upper layer is paved, exhibits remarkable strength.

(3) As a paving machine, it is easy to install a scarifier in front of the screw spreader of a conventional asphalt finisher, and there is no modification cost. (4) The Scar+7 Fire is removable and attachable to the paving machine. The height is also adjustable, so after the paving work on the lower layer is completed, the series of work up to the paving work on the upper layer can be continued without any time lag.

Therefore, the characteristics of roller-compacted concrete pavement, such as fast construction speed and shortened construction period, can be further improved.

Of course, since the drying shrinkage is small, the effects such as being able to expand the joint spacing and allowing early traffic opening are not hindered in any way.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and Fig. 1 is a side view showing an example of the construction of a paving machine for performing roller compacted concrete paving, and Fig. 2 shows the main components of a paving machine equipped with a scarifier. FIG. 3 is a side view showing the section, and FIG. 3 is a perspective view showing the general structure of the scarifier. A... Dump Toranoku
B... Paving machine C... Vibrating roller D...
・Finish compaction roller E...Scarifier F...
・Paved roadbed 1...Self-propelled vehicle body 2...Homba 3...Screed spreader 4...Screed 4a...Tamper 4b...
・First hybrator 4C...Pressure bar 4d...Second hybrator 1l...Compaction surface 21...Horizontal rod 22...
Canter 23...Arm 24...Guide plate 25...Height adjuster h1...Lower part
h2... Upper part Fig. 3 23

Claims (4)

[Claims] (1) In roller compacted concrete pavement, in which cemented carbide concrete is leveled with an asphalt finisher and then compacted by compaction, a step paving method is used in which the pavement is divided into two layers, a lower layer and an upper layer, depending on the pavement thickness. , after leveling and compacting the lower layer of paving material, the compacted surface of the lower layer is loosened, and the upper layer of paving material is leveled on top of it, followed by compaction and rolling. Construction method of pressed concrete pavement. (2) A hopper that stores paving material made of cemented carbide concrete, a feeder that drops the paving material from this hopper onto the roadbed at the rear, and a feeder that spreads the dropped paving material evenly on the roadbed with a predetermined width. A paving machine equipped with a screw spreader for spreading and a screed for leveling and compacting the spread paving material to a predetermined thickness, wherein a scarifier is placed in front of the screw spreader so that the vertical height can be adjusted freely. A paving machine for roller compaction concrete paving, characterized in that it is detachably installed on the machine body side. (3) The scarifier is a fork-shaped scarifier with multiple cutters hanging down at a constant pitch in the width direction, and is arranged in multiple rows in the front and back, and the cutter positions of the front and rear scarifiers are staggered. A paving machine for rolling compacted concrete pavement according to claim 2, characterized in that the rollers are arranged as follows. (4) The roller compacted concrete pavement according to claims 2 and 3, characterized in that ski-shaped guide plates that slide on the rolling surface of the lower layer portion are attached near both left and right ends of the scarifier. Paving machinery.