JPS6360307A - Method for repairing crack part in asphalt pavement - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the repair of cracks occurring in asphalt pavement of roads, etc., and particularly to the repair of linear cracks such as longitudinal cracks and transverse cracks in asphalt pavement. The present invention relates to a method for repairing cracked portions in asphalt pavement suitable for partial repair.

Cracks in asphalt pavement are a major factor that leads to damage, so it is necessary to repair them in a timely manner.

The crack generation mechanisms can be broadly categorized as (1) Fracture due to fatigue of the mixture, (2) Fracture due to permanent deformation of the mixture, (3) Fracture due to temperature contraction of the mixture, etc. (4) Reflection cracks, etc., and in reality, these cracks occur. It is thought that the mechanism is complicated and the mixture fatigues and cracks occur.

Cracks generated by permanent deformation cracks in (2) can be classified as follows.

(1) Books caused by deformation of the roadbed and roadbed.

Q+) This is due to displacement of the surface layer due to poor adhesion between the surface layer and base layer.

(] Caused by uneven settlement seen around slopes, cut and fill boundaries, underground objects, cross structures, etc.)

(3) Cracks due to temperature shrinkage generally occur in the transverse direction.

(4) Reflection cracks occur when there are cracks in the underlying layer.

This may also be due to the effects of drying shrinkage or curing shrinkage of the underlying layer.

Furthermore, the shapes of cracks can be broadly classified into hexagonal (reticular) and linear.

Recently, there has been a tendency for the proportion of linear cracks, including rut cracks, to increase. For example, in Hokkaido, where the cold is extremely cold and there is relatively little traffic, asphalt paved roads develop transverse linear cracks (2 to 20 m) due to temperature stress.
) can be seen occurring many times. Additionally, in cold regions, there are vertical cracks due to ruts and frost heaving. Moreover, among the construction joints of pavement, mainly the vertical joints open in the winter and do not close in the summer, resulting in cracks. In many cases, cracks in joints that have entered the surface layer propagate linearly from top to bottom to the base layer and roadbed directly below them over time. In addition, cracks occur at the joint between old and new pavement due to patching or replacement.

There is also a reflection crack.

These cracks behave like pavement joints, allowing the cracks to only grow.

Various methods are used to repair these cracked sections of pavement. As for the conventional method, all the dirt and mud contained in the cracks are compressed air. There is a method in which a tack coat is applied by blowing out a tack coat and then filled with Asmol or Booth asphalt, which is a heated asphalt mixture, and a method in which heated injection rubberized asphalt, which is used as an injection joint material for concrete pavement, is injected and filled with joint material. In order to make it easier to fill the crack with metal, it is also possible to cut the crack with a hand cutter or the like. However, heated asphalt mixtures lack bonding and extensibility at low temperatures, so they tend to crack in cold regions. In addition, the use of heat-injected joint material requires that the entire material is heated and melted, and heating and melting takes time. ), and there is a risk of pollution due to the generation of smoke, odor, etc., and an injection machine is required to facilitate the injection process. Also, if the crack is wet with water, the joint material will wipe and will be difficult to fill. Furthermore, the injected joint material is likely to be removed over time by traveling vehicles. Another disadvantage is that the appearance of the paved surface after injection is not clean. In addition, as a cold sealing method, injection sealing using a rubber-containing asphalt emulsion is available, but it has drawbacks such as poor adhesion and thinning due to evaporation of water, making it unsuitable for products with wide cracks. Alternatively, a method has also been implemented in which a heat-injected joint material made of rubberized asphalt is formed into a string shape, which is filled into the crack, and then baked with a baking iron or the like. This method also exposes the joint material to the pavement surface, so it is likely to be removed over time by driving vehicles. However, there are disadvantages such as the appearance of the paved surface is not clean.

In addition, the asphalt pavement in the cracked areas was cut and removed.
There is a method of replacing it with a new heated asphalt mixture, but
This method has problems such as high construction costs and poor adhesion between old and new pavement.

Alternatively, there is a method of fully impregnating a polyester non-woven fabric with asphalt and pasting a tomo sheet over the cracks, and then overlaying a new heated asphalt mixture on top of that, but the construction cost is high, and the cost increases as the paved surface is overlaid. There are disadvantages such as '.

Repairs are carried out in various ways as described above, but at present they have advantages and disadvantages, and there is a need for a method that can quickly repair linear cracks, is economical, and is effective in a sustainable manner. was.

The present invention meets these demands; it is easy to install, provides reliable Kramek sealing, and remains effective even under severe conditions. It provides all repair methods that are effective and have a beautiful appearance.

And, according to the present invention (RI, after injecting asphalt emulsion into cracks on the asphalt pavement surface where cracks such as longitudinal cracks, transverse cracks, etc. have occurred, or without injecting asphalt emulsion, the pavement surface including the cracked part of the pavement surface and which is wider than the cracked part? The upper part of the pavement is heated with a heater to soften it, and then the heated and softened upper part of the pavement is scraped up into grooves with a uniform depth.
Next, a sealing sheet made mainly of asphalt, rubber, polymer, etc., with a width sufficient to cover the entire crack area was laid in the groove, and then the paving material was scraped up. The gist of this article is a method for repairing cracks in asphalt pavement, which is characterized by backfilling the grooves, straightening, and compacting.

The sealing sheet (hereinafter simply referred to as a sealing sheet) whose main materials are asphalt, rubber, and high molecular weight polymer used in the present invention is as follows.

It is a sheet made of a thermoplastic sealing material completely mixed with asphalt, including rubber and polymers, and has excellent elasticity and self-adhesive properties at room temperature or when heated. The sealing sheet can also contain fillers, fibers, plastics, threads, nets, reticulated fabrics, nonwoven fabrics, cloths, knitted fabrics, etc. as reinforcing materials.

This thermoplastic sealant has a softening point of 65-150℃
It has excellent bonding properties at low temperatures.

If the softening point is below 65°C, the heat resistance may be affected and it may flow in the summer, and if it exceeds 150°C, it will not blend well with the base, and the adhesiveness will also decrease, resulting in poor workability. Regarding bondability at low temperatures, there are tensile tests for heat-applied injection joint materials specified in the "Cement Concrete Pavement Guidelines" published by the Japan Road Association, and bond tests such as ASTM and U.S. Federal Standards. Tensile test method for hot-applied grouting joint material (This test method is performed to confirm whether the grouting joint material can ensure complete watertightness of the joint when the concrete plate shrinks. (the most important test), preferably 31 or more at -10°C.

This thermoplastic mixture can also be rubberized asphalt, which is made by heat-melting and dispersing rubber and high-molecular polymers in asphalt, which is known as a heat-applied injection joint material, but in general, it is as follows: .

To improve asphalt's adhesion, bonding strength, elasticity, flame resistance, cold resistance, impact resistance, elongation, weather resistance, etc.
It is modified by completely mixing rubber, nidistomer, etc.

As the rubber and elastomer, those that are compatible with asphalt are used, and they may be used alone or in combination. To give an example of rubber and nystomer,
For example, natural rubber, styrene-butadiene rubber, styrene-imprene rubber, imprene rubber, butadiene rubber, chloroprene rubber, butyl rubber, halogenated butyl rubber, chlorosulfonated polyethylene, chlorinated polyethylene, ethylene-propylene rubber, EPT rubber, alphine rubber, styrene-butadiene rubber. These include diene block polymerization comb, styrene/isoprene block polymerization rubber, ethylene/vinyl acetate copolymer, ethylene/acrylate copolymer, polyethylene, etc. These are used in various forms. Items made of new materials, recycled items, powder items,
There are various kinds such as latex ones.

Examples 2.3 of methods of mixing rubber, elastomer, etc. with asphalt include a method of kneading asphalt with rubber, nydistomer, etc. using a gold rubber roll, a Panbury mixer, etc.

A method in which the kneaded material (masterbatch) is added to completely heated and molten asphalt and mixed while heating for a certain period of time. A method of adding latex or emulsion to completely heated and molten asphalt, heating and mixing to evaporate all water and disperse. Rubber powder (for example, powdered rubber for automobile tires), thermoplastic rubber (for example, styrene-butadiene block copolymer rubber), and ethylene/vinyl acetate copolymer are added to heated and melted asphalt and heated and mixed for a certain period of time. There are methods such as melting and dispersing. These methods are also used in combination.

A thermoplastic solid resin, liquid rubber, liquid resin, softener, plasticizer, etc. may be added as a tackifier along with the above-mentioned rubbers, nidistomers, etc.

For example, rodin and its derivatives, terpene resin, petroleum resin and its derivatives, alkylphenol resin, terpenephenol resin, coumaron indene resin, synthetic terpene resin (for example, Nippon Zeon, trade name Lineton), alkylene resin, polyisobutylene. , polybutadiene, polybutene, copolymers of imbutylene and butadiene (e.g.
These include SK Polymer 1000 (manufactured by Tonen Petrochemical Co., Ltd., trade name), Line (manufactured by Nippon Zeon Co., Ltd., trade name)), process oil, plasticizer, animal and vegetable oils, polymerized animal and vegetable oils, and the like. Furthermore, anti-aging agents, antioxidants, pigments (eg carbon blank), etc. can also be used. Furthermore, it is also possible to partially vulcanize by adding sulfur or other vulcanizing agents.

Fillers include asbestos, synthetic fibers, other fibers, mica powder, stone powder, pigments, and the like. These are thermoplastic compositions 0-3
It is used in a range of 5% by weight without deteriorating adhesiveness, bonding properties, extensibility, etc. These additions completely improve the sheet's heat resistance and impact resistance at low temperatures.

The surface of the sealing sheet is preferably prepared so that it can exhibit its full pressure-sensitive adhesive properties at room temperature or with slight heating, and a peelable I sheet is attached thereto.

The thickness of the sealing sheet is about 1 to 6 thick, but usually 3 to 5 thick is used. If it is thicker than this, the elasticity of the sealing sheet will cause the material to move when the material is backfilled onto the sealing sheet, which is not good.

Moreover, if the thickness is too thin, the sealing effect cannot be sufficiently exerted.

The width of the ceiling sheet is usually 10m, 50.3cm.
It is formed into a tape, such as rn, and is supplied in roll form, although the width can be wider or narrower. If the crack is meandering, what is the width? Good for wide use.

Next, the method of the present invention? The explanation will be given according to the illustrated embodiment. The procedure for repairing cracks in the pavement of the present invention is shown in construction cross-sectional views in order from Fig. 1 to Fig. 6. In the figure,
fil is an asphalt pavement. (2) is a crack that has occurred on the surface of the asphalt pavement (1), and should be thoroughly cleaned before repair (Fig. 1). Then, asphalt emulsion is injected into the crack (2). (3) shows the asphalt emulsion injected into the crack (2) (Figure 2).

Injection of this asphalt emulsion (3) may be omitted depending on the case. (4) is a line heater, and an infrared road heater is used, and crack (2)? The asphalt pavement of the required width is heated and softened, centered on the dowel. (5) shows the paved metal that is heated and softened and scraped (Figure 3). The width of this asphalt pavement that is fully heated is slightly wider than the width of the sealing sheet. Next, raise the upper part (5) of the heated and softened asphalt pavement and make grooves (6). Tsukushi, scraped asphalt paving material (7)? Stack them on both sides of the groove (6). This groove (6)
The depth is approximately 2 to 3 Crn. +81 is a sealing sheet, which is laid over the crack (2) in the groove (6) (Fig. 4).

Next, the scraped asphalt paving material (7) is placed in the groove (6).
), and after leveling the surface, roll it around the entire circumference using rollers, vibroplates, etc. (9) (Figure 5).

In this way, the construction method of the present invention is completed, but a somewhat wide seal coat is subsequently applied on the backfilled asphalt pavement.
- It is best to apply α1 (Figure 6). This sealco)
Although seal coat 01 can be omitted, it is better to apply seal coat 01 when opening to traffic immediately after construction or in winter. The seal coat may be applied by a general method such as, for example, spreading asphalt emulsion all over and then spreading asphalt-coated sand.

In the above process, the asphalt emulsion used for injecting the asphalt emulsion into the cracks shown in FIG. 2 is generally a seepage emulsion, but one with high viscosity and high concentration is preferable. Injection of this asphalt emulsion has the following effects. In most cases, the asphalt mixture lacks the required amount of asphalt in the cracked area. Moreover, since soil and sand are trapped in the cracked areas, when the asphalt is heated and softened using a line heater and the cracked area is paved and scraped up, the amount of asphalt in the scraped paving material tends to be even more insufficient. be. The injection of asphalt emulsion is
This insufficient amount of asphalt can be completely supplemented.

The asphalt of the asphalt emulsion is mixed into the paving material during the heating by line heaters, raking, and backfilling operations.

Since the base surface of the groove after raking up the heat-softened pavement area is heated, the sealing sheet will adhere well to the base simply by spreading it out while pressing it lightly. After that, the paving material ring is scraped up and put back in. Since it is backfilled while it is still hot like a heated mixture, it is easy to work and level and compact. Furthermore, the backfilling paving material becomes integrated with the underlying asphalt pavement through the sealing sheet. If the crack is wide, use a sealing sheet? Before laying the
It is also effective to completely fill the upper part of the crack with a string-like rubberized asphalt-based joint material and then lay the sealing sheet 1.

As mentioned above, the method of the present invention involves heating and softening (2 to 3 crn depth) using an infrared road heater or the like to prevent thermal deterioration as much as possible in a fixed width at the center of the cracked part of asphalt pavement where cracks have occurred. ) and raised in a groove shape, and the area has great elasticity and elasticity even at low temperatures. We have installed a sealing sheet i that provides full sealing effect without loss.
Backfill, level, compact and finish. Alternatively, it can be further finished with a seal coat. Also, a heater? By injecting asphalt emulsion into the cracks before application, the entire amount of asphalt in the backfilled pavement can be supplemented and strengthened.

The features and effects of the method of the present invention will be explained.

1) The sealing sheet is embedded, so there is no risk of it peeling off.

2) The sealing sheet seals the crack inside, not on the pavement surface, and seals not only the crack area but also a sufficient width, making it easy to take advantage of the characteristics of the sealing sheet.

3) The sealing sheet is not heated and melted and then injected, but instead is a molded product, so there is no risk of thermal deterioration, the finished mold is stable, and it is easy to handle.

4) Since the sealing sheet is sandwiched between the composite materials, it can sufficiently cope with vertical and horizontal displacements.

5) Since this method does not use cutters or the like, it is heated, softened, dug up, and buried, so the backfilled paving material behaves as one with the existing pavement.

6) The backfilled paving material supplements the entire amount of asphalt that was insufficient in the use of asphalt emulsion and is recycled as a heated asphalt mixture, thus forming a stable pavement after compaction.

7) The repaired area by the method of the present invention has good flatness;
The appearance is also good.

8) The method of the present invention has good workability, is easy and reliable, can be opened to traffic immediately after construction, and has significantly improved durability of pavement.

Next, examples will be described.

Example 1 Sealing sheet: A thermoplastic mixture of asphalt, rubber, and polymer, with high elasticity and excellent bonding properties at low temperatures. Formed into a tape with a thickness of 4M and a width of 10cr11, with a release sheet attached. Furthermore, Celloseal SS passes the quality standards for cement concrete pavement injection joint materials.

Example of repairing cracks in asphalt pavement with linear cracks in the longitudinal and transverse directions After cleaning the cracks, a cationic asphalt emulsion for seeping into the cracks at a high concentration SP Catiosol (Nichirei Kagaku Kogyo product, trade name) Evaporation residue 67% by weight, evaporation residue penetration (25
C) 180) is injected at a rate of approximately 0.3 t/m of crack length. Next, the width around the crack is about 15 cr.
The asphalt pavement surface of n is heated and softened using an infrared line heater. Heat-softened pavement part? Create a groove by raking it up to a depth of 2 to 3 cIn, and stack the raked paving material on the outside of the groove. Next, the sealing seatra release sheet? While peeling it off, lay it on the bottom of the groove. And the paving material that was scraped up as if chasing after it? Backfill, top surface? Adjust and finish by compacting with a vibro plate. The repaired areas will be finished to the same level as the conventional road surface.

Cationic asphalt emulsion PK-10.4 to 0.61 for use as a seal coat to penetrate a wider area than the repaired area
Spread 7m2f and cover it with asphalt-covered burnt sand 0.
Spray at a rate of 5 tons/100 m2 and open to traffic immediately. After opening to traffic, the surface of the pavement is flat and looks good. There are no cracks in the repaired areas of the pavement and it is maintained in good condition.

[Brief explanation of drawings]

In the drawings, FIGS. 1 to 6 sequentially show the construction procedure of the method of the present invention, and all are construction cross-sectional views. In the figure, (+1 is an asphalt pavement with cracks, (2) is a crack, and (3) is a cracked (2)
), (4) is a line heater, (5) is the part heated and scraped by a line heater, (6) is the groove, (7) is the scraped pavement, (
8) is a sealing sheet, (9) is a rolling device such as a roller or a vibroplate, and aO is a sheet coat.

Claims (1)

[Claims] (1) After injecting asphalt emulsion into cracks on the asphalt pavement surface where cracks such as longitudinal cracks and transverse cracks have occurred, or without injecting asphalt emulsion, heat the pavement surface wider than the cracked part, including the cracked part of the pavement surface, using a heater. The upper part of the pavement is softened by heating, and the softened upper part of the pavement is then scraped up into grooves of uniform depth, and then asphalt, rubber, and polymer polymer are added into the grooves to a width sufficient to cover the cracks. A method for repairing cracks in asphalt pavement, characterized by laying a sealing sheet mainly made of materials, etc., then backfilling the grooves with the scraped up paving material, leveling it, and compacting it.