JP2003055904A - Method for controlling clouding of pavement using decolorized asphalt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling clouding of pavement using decolorized asphalt making it possible to easily maintain the appearance of the pavement created by the color of aggregate, by easily and effectively controlling clouding of the surface of the pavement without using large-scale machinery or devices. SOLUTION: The method controls clouding of the surface of natural-colored pavement 13 formed by laying an asphalt mixture obtained by admixing decolorized asphalt 11 and aggregate 12. A solution containing D-limonene is applied to the surface as a solvent for dissolving the decolorized asphalt covering the surface of the natural-colored pavement 13, and then the decolorized asphalt 11 is isolated from the surface of the pavement 13 by brushing and washed away using a washing machine that utilizes the force of water, to remove the decolorized asphalt 11 on the surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pavement using decolorized asphalt for suppressing the occurrence of cloudiness on the surface of the pavement formed by laying an asphalt mixture obtained by mixing decolorized asphalt and aggregate. And a pavement structure.

[0002]

BACKGROUND OF THE INVENTION Pavement using decolorized asphalt is formed by laying an asphalt mixture obtained by mixing the decolorized asphalt having a transparent feeling with a colored aggregate such as natural gravel. By expressing a unique color depending on the aggregate used, a landscape pavement such as a so-called natural color pavement is constructed. Such a pavement can express rich natural colors and other colors, the asphalt mixture manufacturing method and construction method are not so different from the ordinary asphalt mixture pavement, and it is relatively inexpensive. For some reason, it has become widely used in Japan.

On the other hand, pavement using decolorized asphalt is
It is a problem that the color of the surface of the pavement becomes cloudy shortly after construction and the scenery is lost. It is clear from the demonstration experiment that such clouding is due to the mechanism that the decolorized asphalt coated on the aggregate of the pavement surface is exposed to sunlight and promotes oxidative deterioration due to ultraviolet rays, resulting in clouding. It has become.
As an existing means for suppressing such clouding, shot blasting (a method of projecting steel balls with a small grain size at high speed) or water jet (a method of using ultra-high pressure water) is used to clean up and pave It is considered that there is a method of removing the cause of discoloration of the decolorized asphalt existing on the surface of the product such as alfalt content or mortar content, and a method of adding a small amount of a yellow pigment to the mixture to make the discoloration inconspicuous.

However, in the case of the former shot blast or water jet, a large blasting effect can be obtained, but the cost is high because a special and large-scale machine knitting is required, and it is suitable for small-scale pavement. Absent. When applying the latter method of making discoloration inconspicuous, it deviates from the original purpose of pavement using decolorized asphalt, in which a landscape is expressed by the color of the aggregate itself because a pigment is used.

The present invention has been made in view of such conventional problems, and easily and effectively suppresses the clouding of the surface of the pavement without using a large-scale machine or device, and An object of the present invention is to provide a method for suppressing clouding of a pavement using a decolorized asphalt and a pavement structure, which makes it possible to easily maintain a landscape of the pavement with its own color.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to a method for suppressing white turbidity which suppresses the occurrence of white turbidity on the surface of a pavement formed by laying an asphalt mixture obtained by mixing decolorized asphalt and aggregate. That is, a solvent that dissolves the decolorized asphalt covering the surface of the pavement is applied to the surface of the pavement, and the decolorized asphalt is released from the surface of the pavement and washed away to remove the decolorized asphalt on the surface of the pavement. By providing a method for suppressing clouding of pavement using decolorized asphalt characterized by
The above object is achieved.

The asphalt mixture includes, in addition to the heated asphalt mixture, an asphalt mixture with other decolorized asphalt, such as an asphalt mixture using a light-colored asphalt emulsion at room temperature.

In the white turbidity suppressing method of the present invention, it is preferable to use a solution containing terpenes, alcohols or ketones as a solvent for dissolving the decolorized asphalt.

Further, in the method for suppressing white turbidity of the present invention, it is particularly preferable to use a solution containing limonene as a solvent for dissolving the decolorized asphalt. Here, as the limonene, either D-limonene or L-limonene can be used.

Furthermore, in the method for suppressing clouding of the present invention, a solvent that dissolves the decolorized asphalt is sprayed onto the surface of the pavement and applied, and then the surface of the pavement is polished with a brush to release the decolorized asphalt. It is preferable to remove the decolorized asphalt on the surface of the pavement by rinsing it with a washing machine utilizing water force.

Furthermore, the white turbidity suppression method of the present invention comprises:
It can also be applied after the surface of the laid pavement has turned cloudy.

Further, the present invention is formed by laying an asphalt mixture obtained by mixing decolorized asphalt and aggregate, and the decolorized asphalt on the surface of the pavement is removed by the method for suppressing clouding as described in any one of the above. The above object is achieved by providing a pavement structure characterized in that

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below. According to the present embodiment, as shown in FIG. 1, for example, a natural color pavement 13 is formed by laying a heated asphalt mixture obtained by mixing the decolorized asphalt 11 and the aggregate 12, and the natural color pavement 13 is formed. By removing the decolorized asphalt 11 (including the asphalt content and the mortar content) from the surface by the whitening suppression method described later, the pavement structure 10 of the present embodiment is obtained.

According to the present embodiment, the decolorized asphalt 11 constituting the heated asphalt mixture is a known pavement having a hue from pale yellow to dark green containing petroleum resin, a softening agent and a thermoplastic elastomer as main components. It is a transparent molten mixture for. In addition, decolorization asphalt 11
For example, it is a binder for paving which has physical properties equivalent to those of commonly used petroleum asphalt such as natural asphalt and straight asphalt and can be handled by the same construction method as petroleum asphalt.

Here, the petroleum resin contained in the decolorized asphalt is, for example, petroleum, coal and / or a natural product as a raw material having a molecular weight of 200 to 3000, and is an aliphatic, aromatic and / or cyclic compound. A petroleum resin or a coal-based resin such as a cyclopentadiene resin having a molecular weight in the above range, which is polymerized by a Friedel-Crafts type catalyst by adding phenols such as phenol, catechol, resorcinol, hydroquinone, etc., alone, or a terpene. Resins and natural resins such as various fatty acid esters can be used.

The softening agent contained in the decolorizing asphalt is, for example, a high boiling point paraffin hydrocarbon fraction,
The flash point of aromatic hydrocarbon fractions is 240 ° C or higher, typically 260 ° C or higher, and the kinematic viscosity (40 ° C) is 100 mm.
Heavy mineral oil or the like having a rate of ² / s or more, typically 300 mm ² / s or more can be used.

Further, as the thermoplastic elastomer contained in the decolorized asphalt, for example, a block copolymer of styrene and a conjugated diene such as butadiene or isoprene and a partial hydride thereof can be used.

According to the present embodiment, the aggregate 12 constituting the heated asphalt mixture is made of colored aggregate such as natural gravel, and its particle size is, for example, for coarse-grained asphalt concrete, dense-grained asphalt concrete, or fine It is possible to use various aggregates that have been adjusted to have a particle size such as that for concrete.

Further, according to this embodiment, a filler can be added to and mixed with the hot asphalt mixture composed of the decolorizing asphalt 11 and the aggregate 12.
The filler mainly has a particle size of 0.074 mm or less and is mixed with the decolorized asphalt 11 and the aggregate 12 to improve the durability, temperature sensitivity, consistency and the like of the decolorized asphalt, and to improve the stability of the entire asphalt mixture. It has the function of improving, and for example, limestone stone powder or the like can be used.

According to this embodiment, in the asphalt plant, the decolorized asphalt 11 and the aggregate 12 are weighed to a predetermined blending amount, a filler is blended if necessary, and various additives are appropriately added. By heating and mixing using, for example, a mixing mixer, a heated asphalt mixture for paving with the decolorizing asphalt 11 can be obtained. Bring the obtained heated asphalt mixture to the pavement site for paving sidewalks and roads that emphasize landscape, spread it on the roadbed surface with an asphalt finisher, etc., and then roll it using a vibrating roller etc. According to the construction method similar to the paving with the heated asphalt mixture using ordinary petroleum asphalt, the natural color paving in which the color of the aggregate itself appears on the surface to improve the scenery 1
3 will be formed.

According to this embodiment, after the natural color pavement 13 has been laid, the natural color pavement 13 is cured for about 24 hours, and then the work of removing the decolorized asphalt 11 covering the surface of the natural color pavement 13 is performed. That is, in order to remove the decolorized asphalt 11 by the whitening suppression method of the present embodiment, first, on the surface of the formed natural color pavement 13 using a general simple sprayer, as a solvent to dissolve the decolorized asphalt 11, For example, a solution containing D-limonene, which is an extract from the skin of citrus fruits (lemon etc.), is added at a rate of 10 per 1 m ^2.
It is applied by spraying with a spray amount of about 0 g. As a result, the decolorized asphalt 11 that covers and adheres to the surface of the natural color pavement 13 is dissolved.

When, for example, about 10 minutes have passed with the solution containing D-limonene applied to the surface of the natural color pavement 13,
Next, for example, a polisher (trade name, TP-114, manufactured by Tomojo Construction Machinery Co., Ltd.), which is a simple device equipped with a fern brush
Is used to polish the surface of the natural color pavement 13 at a polishing rate of 180 seconds per 1 m ^2, for example. As a result, the decolorized asphalt 11 attached to cover the surface of the natural color pavement 13 is released. The polishing with the polisher can be performed more effectively by spraying the surface of the natural color pavement 13 with water.

After polishing the surface of the natural color pavement 13, finally, using a simple washer utilizing water force, for example, a high washer (trade name, YSP1615SS-E, manufactured by Yanmar Diesel Co., Ltd.) The surface of the pavement 13 is washed at a washing speed of 180 seconds per 1 m ^2, for example.
As a result, the decolorized asphalt 11 released on the surface of the natural color pavement 13 is washed away, and the decolorized asphalt 11 (including the asphalt content and the mortar content) that causes white turbidity is removed cleanly, and the pavement of the present embodiment is removed. The structure 10 will be obtained.

Here, as the solvent for dissolving the decolorized asphalt 11, in addition to a solution containing D-limonene or L-limonene, various other solvents having a function of dissolving the decolorized asphalt 11 can be used. It is also possible to use an organic solvent such as ethane while appropriately adjusting the coating amount. In addition, it is possible to effectively wash the decolorized asphalt only in the part to be polished with a brush and to dissolve the decolorized asphalt existing inside the pavement so much that it is possible to easily suppress the deterioration of the durability of the pavement. From
As the solvent for dissolving the decolorized asphalt, it is preferable to use a solution containing terpenes, alcohols, or ketones having a small ability to dissolve the decolorized asphalt. If a solution containing naturally-occurring limonene is used as a solvent for dissolving the decolorized asphalt 11, since such a solution is a substance with little harm even if it is put in the mouth, it is safe and easy to construct, and the surrounding environment Little impact on.

According to this embodiment, the surface of the natural color pavement 13 can be easily and effectively suppressed from becoming cloudy without using a large-scale machine or device, and the landscape of the pavement with the color of the aggregate itself can be suppressed. Can be easily held. That is, according to the present embodiment, the D
A solution containing limonene can be easily applied to the surface of the natural color pavement 13, and the decolorized asphalt 11 can be easily washed away by being released from the surface of the natural color pavement 13 using a simple polishing device and a washing machine. be able to. Therefore,
By combining a simple device that can be leased for general purposes, regardless of the size of the pavement site or the type of pavement such as a sidewalk or roadway, it effectively suppresses clouding without requiring special skills or equipment. It is possible to carry out the work, and it is possible to easily reduce the construction cost.

Further, according to this embodiment, the decolorized asphalt 11 itself, which causes white turbidity, is replaced with the natural color pavement 13.
Since it suppresses clouding by removing it from the surface of the pavement, it becomes possible to easily maintain the pavement landscape due to the color of the aggregate for a long period of time, and the decolorized asphalt 11 inside the natural color pavement 13 is not removed. The durability of the natural color pavement 13 is hardly affected.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, the aggregate that constitutes the pavement does not necessarily have to be natural gravel, various other colored aggregates can be used, and the pavement does not necessarily have to be a natural color pavement. Further, the method of applying the solvent that dissolves the decolorized asphalt to the surface of the pavement does not necessarily have to be by a spraying device, and the method of releasing the decolorized asphalt from the surface of the pavement and washing it off uses a brush or water force. It is not always necessary to use a washing machine. Furthermore, the present invention can also be adopted as a means for repairing pavement using decolorized asphalt that has already been paved and has its surface turned cloudy. Furthermore, the present invention can be applied not only to paving with a heated asphalt mixture but also to paving with various other decolorized asphalts such as paving with an asphalt mixture using a light-colored asphalt emulsion at room temperature.

[0028]

The present invention will be described in more detail based on the following examples and comparative examples, but the present invention is not limited thereto.

Example 1 A pavement structure by natural color pavement using decolorized asphalt, which was paved in the same manner as in the above-mentioned embodiment and in which the decolorized asphalt on the surface was removed by the same cloudiness suppression method as in the above-mentioned embodiment Was used as the sample of Example 1, and the surface turbidity and the durability were evaluated by a visual test for turbidity and a cantablo test described below. The evaluation results are shown in FIGS.

[Comparative Example 1] A pavement structure of a natural color pavement using decolorized asphalt that was paved in the same manner as in the above-mentioned embodiment and has not been treated to suppress clouding Then, the surface turbidity and the durability were evaluated by a visual opacity visual test and a cantabulo test described later. The evaluation results are shown in FIGS.

[Comparative Example 2] Decolorization was performed by paving in the same manner as in the above-mentioned embodiment, and decolorized asphalt on the surface was removed by scouring using a conventional water jet (construction method using ultra-high pressure water). The pavement structure of natural color pavement using asphalt was used as the sample of Comparative Example 2 and the surface opacity was evaluated by a visual test for opacity described below.
The evaluation result is shown in FIG.

[Visual Test for Whitening] The specimens of Example 1 and Comparative Examples 1 and 2 are exposed outdoors for 3 months, and the change in surface color is visually observed. When it is recognized that the surface color has not changed at all, it is "◎", when it is recognized that the surface color has hardly changed, it is "", and when it is recognized that the surface color has changed slightly. The white turbidity of the surface was evaluated by setting “Δ” and “×” when it was recognized that the color of the surface was changed. The evaluation result is shown in FIG.

According to a visual test for clouding, the specimen of Example 1 was compared with the specimen of Comparative Example 1 whose surface was untreated,
The asphalt content and mortar content of the decolorized asphalt on the surface were sufficiently abraded, and a good abraded state comparable to that of Comparative Example 2 treated with a water jet was obtained, and FIG. As shown in FIG. 5, it is found that the surface color of the sample of Example 1 does not change much like the sample of Comparative Example 2. Therefore, it becomes clear that the present invention is effective as a method of effectively suppressing clouding of the pavement using the decolorized asphalt.

[Cantablo Test] This is a test performed to evaluate the aggregate scattering resistance of the asphalt mixture, and the test result (cantablo loss rate) is known to have a close correlation with the durability of the asphalt pavement. Has been. For the Cantablo test, "Pavement Test Method Handbook Separate Volume (Provisional Test Method), October 1996, Japan Road Association" 1-1
-2 According to the Cantablo test method, the general procedure is as follows.

(1) Manufacture of Specimen Using a cylindrical mold having an inner diameter of 101.6 mm, height 6
Create a 3.5 mm specimen. That is, after putting the above-mentioned heated asphalt mixture using decolorizing asphalt in a cylindrical mold and compacting it, after kneading while allowing to cool to room temperature, the solid pavement material is extracted from the mold, and the above-mentioned on the surface. Example 1 was carried out by applying the method for suppressing whitening.
The test piece of Comparative Example 1 is a test piece of Comparative Example 1 which is not subjected to any surface treatment.

(2) Execution of test After measuring the mass of the specimen, it is aged at 20 ° C. for 20 hours. Put the cured specimen into the drum of the Los Angeles tester and rotate the drum at 30 to 33 rpm
Rotate 0 times. After rotating a required number of times, the sample in the drum is taken out and its mass is measured.

(3) Calculation of Loss Ratio The mass lost due to scattering is calculated from the mass of the specimen before and after the test, and the ratio of the mass before the test to the mass lost is calculated and expressed as a percentage by the Cantablo test. The mass loss rate. That is, the mass loss rate (%) is [(mass of test sample before test (g))-(mass of test sample after test (g))] / (mass of test sample before test (g)) Is a value expressed as a percentage. The test results are shown in FIG.

According to the test results shown in FIG. 3, the sample of Comparative Example 1 in which the surface of the decolorized asphalt was not treated, and Example 1 in which the surface of the decolorized asphalt was removed by the above-described whitening suppression method It was found that the mass loss rate (%) by the Cantablo test with the specimen of No. 1 was almost the same. From this result, it becomes clear that the present invention hardly affects the durability of the pavement using the decolorized asphalt.

[0039]

As described in detail above, according to the method and the pavement structure for suppressing the whitening of a pavement using the decolorized asphalt of the present invention, the whitening of the surface of the pavement can be achieved without using a large-scale machine or device. Can be easily and effectively suppressed and the landscape of the pavement due to the color of the aggregate itself can be easily maintained.

[Brief description of drawings]

FIG. 1 is an enlarged partial sectional view illustrating a configuration of a pavement structure according to an embodiment of the present invention.

FIG. 2 is a table showing test results of a white turbidity visual test.

FIG. 3 is a chart showing test results of a cantablo test.

[Explanation of symbols]

10 pavement structure 11 Decolorization asphalt 12 aggregate 13 Natural color pavement

Continued front page    F-term (reference) 2D051 AF01 AG11 AG18 AH02 EA06                       EB07                 2D053 AA22 AD01 AD03

Claims (7)

[Claims] 1. A method for suppressing clouding of a surface of a pavement formed by laying an asphalt mixture obtained by mixing decolorized asphalt and aggregate, wherein the surface of the pavement is suppressed. A solvent that dissolves the decolorized asphalt covering the surface of the pavement is applied, and the decolorized asphalt is released from the surface of the pavement and washed away to remove the decolorized asphalt on the surface of the pavement. A method for suppressing the cloudiness of a pavement using. 2. The method for suppressing clouding of pavement using decolorized asphalt according to claim 1, wherein the asphalt mixture is a heated asphalt mixture. 3. The method for suppressing clouding of pavement using decolorized asphalt according to claim 1, wherein the solvent that dissolves the decolorized asphalt is a solution containing terpenes, alcohols, or ketones. 4. The method for suppressing clouding of pavement using decolorized asphalt according to claim 1, wherein the solvent that dissolves the decolorized asphalt is a solution containing limonene. 5. A solvent that dissolves the decolorized asphalt is sprayed onto the surface of the pavement and applied, and then the surface of the pavement is brushed to release the decolorized asphalt.
The decolorized asphalt on the surface of the pavement is removed by rinsing with a washing machine utilizing water force, and the method for suppressing clouding of pavement using the decolorized asphalt according to any one of claims 1 to 4. . 6. The method for suppressing clouding of pavement using decolorized asphalt according to claim 1, wherein the method is carried out after clouding has occurred on the surface of the laid pavement. 7. The decolorized asphalt on the surface of the pavement is formed by laying a heated asphalt mixture obtained by mixing decolorized asphalt and aggregate, and the decolorized asphalt on the surface of the pavement is produced by the method for suppressing clouding according to any one of claims 1 to 6. A pavement structure characterized by being removed.