JP2003160902A - Construction method of composite pavement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of work execution for composite pavement with better surface conditions than before. <P>SOLUTION: In a method of work execution for composite pavement in which slurry containing a water-hardening agent is injected and solidified in the clearances of asphalt mixtures prepared beforehand, this method is characterized in that after slurry is injected, the slurry remaining on the surface is removed before it solidifies to expose the asphalt mixtures. In this case, the water- hardening agent to be used may be either a cement based hardening agent or a material that can display water retaining ability after it solidifies. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a composite pavement, and more specifically, it is made into a composite pavement by injecting and solidifying a water slurry containing a hydraulic solidifying material into the gaps of an asphalt pavement that has been constructed in advance. At this time, the present invention relates to a technique for removing the residual portion of the injected water slurry to improve the condition of the pavement surface.

[0002]

2. Description of the Related Art Asphalt pavement generally has a structure in which rainwater does not penetrate into the lower part of the pavement. However, in recent years, an increasing number of pavements have water permeability and drainage properties (hereinafter referred to as permeability and drainage properties) that allow rainwater to permeate into the pavement (permeate underground). Specifically, bricks having a water permeable function are spread, or asphalt pavement having a porosity of 10% or more is constructed. Both
In order to quickly permeate water from the drainage functional layer to the wastewater treatment facility, continuous voids are included at a high volume ratio from the upper layer to the lower layer of the pavement. The reason for using such pavement is to reduce water pools on the pavement, to prevent water splashing and slipping when the vehicle is running, to reduce noise, and to improve the living environment.

Recently, not only the problems closely related to the living environment, but also the improvement of the entire social environment has been paid attention to.
As one of them, suppression of the heat island phenomenon has become a subject for study. This heat island phenomenon is because the asphalt, concrete, bricks, etc., which make up the city, easily store heat, so the surface temperature rises significantly, especially in the summer, and the cooling does not progress after the heat swelling, so the tropical night It means normalization and not only worsens the environment in cities, but also becomes a major social problem as one of the global warming phenomena. In addition, the deterioration of the environment is being accelerated by the increase in the amount of waste heat due to the increase in the amount of energy used by air conditioners and the like.

The heat island phenomenon is caused by the fact that the ground originally covered with soil or tree planting is replaced with asphalt or concrete. If the ground is soil, etc., when it rains, water will be stored in the underground space, which will evaporate during clear weather and deprive the heat of vaporization, which can lower the temperature. It is considered that the water flows into the drainage channel almost without penetrating into it, and even if it becomes sunny, cooling due to heat of vaporization does not occur. Also,
The ground covered with asphalt and the like cannot be treated because the load of the drainage facility becomes too large when a large amount of rainfall occurs, which causes a new problem of urban flood.

The load on this drainage facility can be greatly reduced by providing a transparent and drainage pavement to enhance the drainage treatment capacity. However, regarding the high temperature of pavement,
It is not possible to solve this problem simply by constructing a transparent / drainable pavement because it cannot hold the water that causes evaporative cooling inside. Also, as a measure against high temperature, it is possible to simply return the road surface from asphalt or concrete to soil, but it is convenient to prevent sand dust during drying and runoff during heavy rain, which is the reason why these materials have been replaced Will be greatly lost. In addition, measures are being taken to expand the greening area. This measure has the advantages of reducing the amount of CO ₂ released to the atmosphere and improving the landscape, in addition to suppressing the heat island phenomenon, but the above-mentioned problems such as suppressing dust and the like are not solved. There is an extra problem of maintenance and management, and it cannot be applied anywhere on the road.

Therefore, the applicant of the present invention has previously proposed, in Japanese Patent Application No. 2001-324677, a pavement having both permeability and drainage and water retention as a means for solving the problem of high temperature. That is, the asphalt mixture is pre-installed in a state where a gap is created, and the gap of the asphalt mixture is partially filled with a separately prepared water retaining material (also referred to as a water-hardening material), and the upper surface to the lower surface and / or the side surface of the pavement. Is a pavement in which the voids communicating with the pavement are left (because different materials are divided into two parts to form a pavement body, this is defined as a composite pavement). The structure of this composite pavement is schematically shown in FIG. 1, in which a part of the gap 2 formed in the asphalt mixture 1 is filled with a water retaining material 3 capable of holding water, and the pavement from the upper surface to the lower surface. And / or the voids 4 communicating with the side surfaces are left to facilitate the permeation and drainage.

In order to construct the composite pavement, first, a pavement body having a gap as represented by an open-grain size asphalt is constructed, and then a material exhibiting water retention after solidification (hereinafter referred to as a water retention material). ) 3 is injected into the gap 2 from above. At that time, the injection of the slurry,
The water-retaining material 3 after solidification is performed in such an amount that the gap 2 does not fill the entire gap 2 and the void 4 remains. Further, after the injection, in order to make the water retaining material 3 sufficiently penetrate into the gap 2, appropriate vibration is applied. This completes a composite pavement having a continuous water retention layer and voids from the top to the bottom.

It has been confirmed that the composite pavement thus constructed has excellent functional properties such as permeability, drainage and water retention. However, it has been found that the surface layer tends to be slightly peeled off. By applying vibration, most of the slurry penetrates into the gaps of the asphalt pavement, but a layer of water retaining material remains on the surface. A composite pavement with such a surface condition does not cause a problem when it is used for sidewalks, but since the layer thickness of the remaining water retaining material is extremely thin, when it is used in a place where a strong external force acts such as a roadway, The surface layer is often peeled off by being caught on the tire contact surface of a car. In other words, permeability, drainage and water retention are expressed by the voids inside the pavement and the water retention material layer, so there is no problem in terms of properties, but there is uneven color on the surface or the peeled water retention material causes dust. Such a problem occurred.

Such a problem is caused by a so-called "semi-flexible pavement" in which the voids of the asphalt mixture are completely filled with cement paste, and a water-retentive water-retaining property in which the voids are completely filled with a water retaining material. It occurs even when paving.
These are all composite pavements like the above pavement, so after applying an asphalt pavement with a gap,
It is constructed by injecting separately prepared cement slurry or slurry containing water retaining material. However, since the gap is completely filled with cement or a water retention material, a little more slurry than the volume of the gap is injected. As a result, excess slurry remains on the pavement. The remaining slurry is
After that, using a rake to scrape it manually,
Although it is removed by a surface treatment apparatus called a scraper as disclosed in Japanese Patent Laid-Open No. 102516, since the surface is only squeezed in practice, a layer of thin cement or a water retaining material is always left on the surface of the pavement. After all, such a surface layer is the same as the water retaining material remaining on the surface in the above-mentioned composite pavement having both the permeability, drainage property and water retaining property, and will be peeled off when the vehicle runs. There is no problem if the entire surface is evenly removed, but it is easy to get it only in the place where the car has run, so ruts occur, and discoloration occurs along the ruts, and the cement-based color appears to be missing.

The layer of cement or water retaining material usually has a white color tone. Therefore, on the road surface where they remain on the surface, the distinctiveness from the white line of the traffic instruction drawn there is deteriorated and it is safe. It becomes an upper problem. As a countermeasure, it is conceivable to mix pigments of different colors to change the color tone, but there is also a problem that economic efficiency cannot be denied.

[0011]

SUMMARY OF THE INVENTION In view of such circumstances, it is an object of the present invention to provide a method for constructing a composite pavement whose surface condition is better than before.

[0012]

[Means for Solving the Problems] In order to achieve the above object, the inventors examined the improvement of the surface condition of the composite pavement as follows. First, as a basic method for suppressing the peeling of the surface layer of the pavement, it is conceivable to strengthen the bonding force. Specifically, it is considered that a material having an adhesive effect is added at the same time as the slurry to be injected into the gap, or after the slurry is injected, a coating for reinforcement is applied to the surface thereof. However, if the adhesive material is mixed with the slurry, the adhesive is also added to the slurry that penetrates into the unnecessary gap, which is uneconomical.
Further, in the water-retentive pavement, the adhesive may change the fine structure of the water-retaining material layer, resulting in a decrease in water retention. Further, in the coating treatment, there is a possibility that the water retaining function itself of cooling by vaporizing water from the surface does not work. Therefore, the inventors came back to its essence and studied, and came to the idea that the problem of surface layer peeling would be solved if the phenomenon of slurry remaining in the form of a thin film was eliminated, and that idea was embodied in the present invention. I did.

That is, according to the present invention, in a method of constructing a composite pavement in which a slurry containing a hydraulic solidifying material is injected into a gap of a pre-applied asphalt mixture and solidified, the slurry remaining on the surface after the injection of the slurry is removed. This is a method for constructing a composite pavement characterized by removing the asphalt mixture before starting the solidification and exposing the asphalt mixture. In this case, the hydraulic solidifying material may be either a cement-based solidifying material or a material that exhibits water retention after solidification. Also,
The injection amount of the slurry may be an amount that completely fills the gap, but the gap of the asphalt mixture is partially filled with the material exhibiting the water retention property, and the voids communicated from the upper surface to the lower surface and / or the side surface. May be left. Further, in the present invention, it is preferable that the slurry remaining on the surface is separated and removed from the surface with a rotating brush, or separated and removed from the surface with an absorbent sponge.
Then, the slurry separated from the surface by the rotating brush,
Alternatively, the slurry separated from the sponge for absorption and removed from the sponge using a blade is preferably collected by suction, and more preferably the slurry collected by suction is recycled for the injection. In addition, in the present invention, the slurry containing the water-hardening material is injected into the gap of the asphalt mixture, the slurry penetrates into the gap by vibration, the slurry remaining on the surface is separated and removed, and the slurry is separated and removed. It is preferable to continuously return the slurry to the recovery container.

According to the present invention, the surface solidified layer due to the residual slurry injected in the latter half of the construction is not formed on the surface of the pavement after the construction is completed, and the composite pavement having a surface better than before can be obtained. . As a result, even if the composite pavement is applied to a road surface on which a heavy load such as an automobile runs, the peeling of the surface layer and the difficulty of recognizing the traffic instruction white line are eliminated.

[0015]

DETAILED DESCRIPTION OF THE INVENTION

In the following, considering the background of the invention,
An embodiment of the present invention will be described.

First, the inventors of the present invention diligently studied a solution from the viewpoint that the peeling problem would occur in some form as long as there is a thin residual layer of the water retaining material on the surface of the pavement. Then, it was thought that removing the residue would directly solve the problem. There are two possible removal timings, before and after the water-retaining material solidifies, but once solidified, an external force is required to separate the solidified body, and in addition, to uniformly remove the entire surface layer, Since it is necessary to remove even the most strongly adhered part, it may have a considerable effect on the pavement under the surface layer. In addition, since the surface has subtle unevenness due to aggregates, it is difficult to remove the solidified material that has entered the recess unless an external force is applied well, and such residue is forcibly removed. Any attempt to do so will cause dust generation if subsequently exposed to natural conditions. On the other hand, since it is possible to remove with a comparatively weak force before curing, in the present invention, the removal before curing is an important requirement.

Any method may be used to separate the residual slurry from the pavement surface, but it is preferable to use the following two methods. The first method is to use a rotating brush. As shown in FIG. 2, the brush 6 mounted so as to protrude from the circumference of the rotatable cylinder 5 by a predetermined length has a rotating shaft 7 of the cylinder 5 vertical (see FIG. 2A) or horizontal (see FIG. 2A). 2 (b)) and rotate and contact the surface layer 8 to stably separate the residual slurry. Brush material is vinyl chloride, polypropylene,
Synthetic rubber, nylon, etc. can be used, and the rotation speed may be set appropriately according to the actual situation. The second is a form in which a sponge 10 is attached to the rotating body 9 as shown in FIG.
It is called a sponge type). Since the slurry before solidification has a high water content, it can be sucked into the inside thereof only by bringing the sponge 10 into contact therewith. However,
In this type, since the amount of slurry held in the sponge 10 is limited, the impregnated slurry must be removed by some means, which means will be described later.

Next, regarding the removal of the separated residual slurry from the pavement surface, in the rotary brush type, the slurry separated from the pavement surface scatters, so it is necessary to collect it. Therefore, in the present invention, the vacuum suction type is adopted. This is because it was the most efficient. The residual slurry separated by the rotary brush is scattered in the air, but can be collected without problems by this vacuum suction. Also,
Since the method of removing the residual slurry by the rotating brush and the vacuum suction is the same as the cleaning principle used by the road cleaning vehicle (road sweeper), such a road cleaning vehicle may be used in the present invention.

For the sponge type, it is necessary to frequently remove the residual slurry absorbed from the sponge. Any method of squeezing a sponge can be applied, but as a result of examination, it is simplest and most efficient to remove it with a pressing plate (called a blade) 11 as shown in FIG. Obviously, the present invention decided to adopt this method.

Subsequently, the residual slurry collected as described above may be accumulated and then discarded in another place. However, in terms of environmental issues, it is more desirable to reuse. Therefore, in the present invention, the original slurry tank used before the injection is returned. This is because the amount of waste can be reduced and resources can be effectively used.
However, since the residual slurry is a hydraulic material, there is a possibility that the characteristics of the slurry may change if the residual slurry that has been dried to some extent is returned to the slurry tank. Therefore, ideally, after pouring the slurry into the gap, the slurry that remains on the pavement surface should be collected as soon as possible and returned to the slurry tank. From this point of view, in the present invention, it is decided to sequentially perform the injection of the slurry, the application of vibration, the removal of the surface residual slurry, the collection, and the return to the tank without a break.

For such continuous implementation, it is not necessary to integrate the devices, and it is sufficient to divide them into a plurality of devices and process them continuously. For example, with a device that injects the slurry into the gap of the asphalt pavement that has been preliminarily constructed, after the injection, an external force is applied to the pavement by plate treatment or vibrating roll treatment so that the slurry penetrates into the gap. Subsequently, the residual slurry on the pavement surface is separated, removed and collected by the above-mentioned residual slurry removing device. The recovered residual slurry may be promptly returned to the original slurry tank via a hose or the like.

As another method, a method in which the slurry injecting device and the vibrating device are integrated with each other, and the device for separating and recovering the residual slurry is continuously run after the device. In addition, after injecting with the slurry injecting device, an integrated device for vibration and separation / recovery may be continuously run. Furthermore, it is possible to use a device that completely integrates slurry injection, vibration, separation and recovery. By using such a device, it becomes possible to uniformly remove the layer of hydraulic material remaining in a thin film over the entire surface of the pavement, and radically solve the problem of surface peeling after solidification. can do. Further, since the present invention collects and reuses the slurry, it is useful for effective use of resources and reduction of waste.

The improvement situation of the pavement surface by the construction method according to the present invention as described above will be explained based on the schematic diagram shown in FIG. When the present invention is not applied, as shown in FIG. 4 (a), a thin surface layer 8 of the water retaining material remains on the surface, and since it is not bonded to the asphalt, it is easily peeled off. It is in. Moreover, since the surface layer 8 is located on the uppermost surface, the surface layer 8 is in a state of being easily contacted by an external force, and peeling or the like may occur during use, which may cause generation of dust.
On the other hand, when the construction method according to the present invention is applied, the slurry remaining on the asphalt 12 and the aggregate 14 is removed, as shown in FIG. As a result, the remaining water retaining material is only the layer connected to the inside of the gap, and the bonding force acts, so that it does not easily peel off. Moreover, the highest position of the layer is asphalt 1
Since it leans against 2, it is in a state where it is difficult for external force to contact,
The peeling phenomenon does not occur any more. In addition, since the color of asphalt is exposed on the surface of the pavement, it has a dark gray color overall, and the visibility of white and yellow lines is significantly improved without using pigments, etc., ensuring a safe environment for roads. It becomes possible to do.

At the end of the explanation, the hydraulic solidifying material used in the composite pavement according to the present invention is a material that exhibits water retention after solidification, and a cement-based solidifying material that improves "flexibility". (For example, ordinary Portland cement, early-strength cement, jet cement, etc.) may be used. Further, as the material exhibiting water retention after solidification, a mixture of a conventionally known silt material with cement or a mixture of water-absorbing polymer with cement may be used, but the applicant of the present invention first applied for it. In 2001-323736, "Blast furnace slag fine powder and amorphous SiO ₂
It is preferable to use "a hydraulic solidifying material composed of an inorganic powder containing 0 mass% or more and an alkali stimulant". It has higher water retention capacity and strength, and has the "heat island phenomenon".
This is because it is effective in suppressing

[0026]

EXAMPLES Next, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

40 parts by weight of inorganic powder containing 50% by weight or more of amorphous SiO ₂ when 100 parts by weight of fine powder of blast furnace slag is set to 100 parts by weight of the gap of the open-grain size asphalt (porosity 24%) which has been applied in advance. , Ca as an alkali stimulant
A water slurry containing a water-retaining material made of a mixed powder containing 25 parts by weight of (OH) ₂ was poured from above in an amount corresponding to 50% of the porosity and solidified to construct a composite pavement. In addition, here is the volume ratio of the gap of the asphalt pavement,
(Company) Method of measuring continuous porosity by Japan Road Association (edited by Japan Road Association, “Drainage Pavement Technology Guideline (Draft)”,
Publisher: Maruzen, 1996) refers to the continuous porosity. The porosity after the construction of the water retention material refers to the continuous porosity measured by the above continuous porosity measurement method after sealing the fine pores of the water retention material with paraffin.

Immediately after solidification of the obtained pavement and when the construction method according to the present invention was adopted (invention example) and when the composite pavement was naturally solidified after injection (comparative example), After solidification, wheels were run on the surface of the pavement, assuming an automobile. Then, the change in the surface state corresponding to each case was observed. An example of the observation result is shown in FIG.

According to the construction method of the present invention, in any construction, after the construction, the appearance was such that the black of the asphalt mixture was scattered on the base consisting of the grayish white water retaining material. In this case, since the entire surface is uniform in this state, there is no unevenness in appearance. On the other hand, when it was naturally cured, the whole was uniformly grayish white.
When the above wheels were run on the surface of such a pavement, the pavement produced by the construction method according to the present invention had no change from the appearance immediately after solidification as described above, whereas the pavement made by the comparative example naturally cured. Then, at first, there was no change, but as the number of times the wheel ran increased, a phenomenon was observed in which only the part where the wheel ran separated, and the appearance looked like a rut. In addition, some of the surfaces peeled off remained as thin films, and some had powdery parts, and it was presumed that the bonding strength was not sufficient.

From the above, it is clear that if the residual slurry on the surface is removed in advance before solidification, a composite pavement having a stable appearance can be surely obtained. In other words, it can be said that the possibility that dust or the like will be generated later has decreased.

[0031]

As described above, according to the present invention, the surface peeling phenomenon in the pavement in which the asphalt mixture and the hydraulic solidifying material are combined is drastically eliminated. As a result, surface peeling can be solved in a composite pavement that has both permeability / drainage and water retention, so the present invention can expand the range of utilization of the composite pavement that has both permeability / drainage and water retention. Become. Further, not only the possibility of dust generation is reduced as much as possible, but also the visibility of the white line or the like of the traffic instruction is improved, and the safety of the road environment can be achieved. In addition, it will contribute to the suppression of the heat island phenomenon that occurs in cities, energy conservation, effective use of rainwater, and improvement of the pedestrian environment.

[Brief description of drawings]

FIG. 1 is a diagram showing a composite pavement having both permeability / drainage property and water retention property, where (a) is a surface viewed from above, and (b) is a longitudinal section.

2A and 2B are views showing a rotating brush used in a method for constructing a composite pavement according to the present invention, in which FIG. 2A is a vertical rotating shaft, and FIG. 2B is a horizontal rotating shaft.

FIG. 3 is a view showing a sponge type surface residual slurry removing device.

FIG. 4 is a vertical cross-sectional view of the composite pavement, where (a) shows a case where a thin water retaining material layer remains on the surface, and (b) shows a case where no thin water retaining material layer remains.

FIG. 5: Assuming an automobile immediately after solidification and after solidification of the obtained pavement, divided into a case where the construction method according to the present invention is adopted (invention example) and a case where the pavement is naturally solidified after injection (comparative example). It is a photograph which shows the observation result of the surface state when a wheel is run on the surface of the pavement.

[Explanation of symbols]

1 asphalt mixture 2 gap 3 Water retaining material (water solidified material) 4 void 5 rotating cylinders 6 rotating brush (brush) 7 rotation axis 8 surface layer 9 rotating body 10 sponge 11 blades 12 asphalt 13 Roadbed 14 Aggregate 15 Vacuum suction device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroaki Onuma             1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Made in Kawasaki             Technical Research Institute of Iron Co., Ltd. F-term (reference) 2D051 AA01 AA02 AA08 AF02 AG01                       AH05 EA01 EA06

Claims (9)

[Claims] 1. A method of constructing a composite pavement in which a slurry containing a hydraulic solidifying material is injected into a gap of a pre-assembled asphalt mixture to solidify, and after the slurry is injected, the slurry remaining on the surface is solidified before starting to solidify. A method for constructing a composite pavement, which comprises removing and exposing the asphalt mixture. 2. The method for constructing a composite pavement according to claim 1, wherein the hydraulic solidifying material is a cement-based solidifying material. 3. The method for constructing a composite pavement according to claim 1, wherein the water-solidified material is a material that exhibits water retention after solidification. 4. The amount of the slurry injected is such that the gap of the asphalt mixture is partially filled with the material exhibiting the water retention property and the voids communicating from the upper surface to the lower surface and / or the side surface remain. The construction method of the characteristic pavement. 5. The method for constructing a composite pavement according to claim 1, wherein the slurry remaining on the surface is separated and removed from the surface with a rotating brush. 6. The method for constructing a composite pavement according to claim 1, wherein the slurry remaining on the surface is separated and removed from the surface with an absorbent sponge. 7. The slurry separated from the surface by the rotating brush, or the slurry separated by the absorbing sponge and removed from the sponge by using a blade is sucked and collected. Construction method of the composite pavement described. 8. The method for constructing a composite pavement according to claim 7, wherein the slurry collected by suction is recycled for the injection. 9. A method of injecting a slurry containing a water-solidifying material into the gap of the asphalt mixture, permeating the slurry into the gap by vibration, separating and removing the slurry remaining on the surface, and removing the separated and removed slurry. The method for constructing a composite pavement according to any one of claims 1 to 9, wherein the return to the recovery container is continuously performed.