JPS61233102A - Construction of bitumenous paving body - Google Patents

Abstract

(57) [Summary] 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 a method for constructing a nine-bituminous pavement that is resistant to abrasion caused by spiked tires, tire chains, etc. in winter and has excellent flow resistance and is less susceptible to abrasion.

In cold regions, paved surfaces are heavily damaged by spiked tires, tire chains, etc. during the winter, and require extensive repair every year. In addition, the dust generated by sushi heshi has developed into a major pollution problem. Therefore, there is a demand for the development of a bituminous pavement with excellent abrasion resistance that can prevent the generation of dust, which is a pollution problem, and save annual repair costs. In addition, in order to restore the flatness of worn road surfaces, asphalt mixtures, etc., are spread and compacted into worn depressions to repair them.
It is also desired that the repair material has excellent abrasion resistance and prevents the progression of abrasion as much as possible. Further, such materials are required to have high sealing properties so that the action of water does not reach the interior of the pavement through cracks or the like. Furthermore, the abrasion-resistant bituminous pavement described above is susceptible to flashing of bituminous materials under traffic, flow and rutting in the pavement even under high summer temperatures and sunlight. There is a demand for something that does not sip and is highly stable.

In addition, reflection cracks are likely to occur in bituminous pavement on a cement-stabilized roadbed along with shrinkage cracks and other cracks that occur in the cement-stabilized roadbed.

Furthermore, if new bituminous pavement is overlaid on a road surface where cracks have occurred in the existing bituminous pavement, there is a risk that flexion cracks will occur next time. Therefore, there is a demand for the development of a bituminous pavement that can also be used as a cushion layer (a layer that prevents reflection cracks) for the surface layer when such reflection cracks occur.

The present invention meets these demands, and has excellent abrasion resistance and flow resistance, and can be used for repairs, maintenance, etc. to prevent reflection cracks, etc., and restore the flatness of the surface layer, cushion layer, and road surface. The present invention provides a construction method for bituminous pavement suitable for

The present invention spreads a bituminous material such as asphalt emulsion on the surface of an existing bituminous pavement or roadbed, and then applies a high maximum coarse aggregate ratio such as open-grained asphalt concrete to the top surface and compares the porosity. An asphalt mixture layer with a high target content is spread and compacted to form an asphalt mixture layer, and then the asphalt mixture layer is heated with a road heater or the like.
Subsequently, the required amount of bitumen emulsion is sprinkled onto the asphalt mixture layer to partially penetrate into the voids of the asphalt mixture layer and coat the surface of the asphalt mixture layer, and then the top surface is coated with hot asphalt. The gist of this paper is a construction method for bituminous pavement, which is characterized by finishing by laying and compacting aggregate.

In the present invention, the existing bituminous pavement refers to an already paved asphalt pavement or other bituminous pavement. This pavement includes high quality pavement, simple pavement, dustproof pavement, narrow surface treatment pavement, etc. Roadbed refers to the roadbed used for bituminous pavement. For example, there are various crushed stone roadbeds, bituminous stabilized roadbeds, cement stabilized roadbeds, lime stabilized roadbeds, bitumen emulsion stabilized roadbeds, bituminous emulsion cement stabilized roadbeds, and the like. Gravel roads are also sometimes used as roadbeds.

In the present invention, the bituminous material such as asphalt emulsion that is sprinkled on the surface of an existing bituminous covering or roadbed is a bituminous material used for tack coats and prime coats. Normal asphalt emulsion, cutback asphalt, paving tar,
Tar emulsion etc. are used.

Also used are bituminous materials modified by adding rubber, nidistomer, etc. (for example, rubber-containing asphalt emulsion, rubber-containing cutback asphalt, etc.).

Asphalt mixtures with a high maximum coarse aggregate ratio and relatively high porosity, such as open-grained asphalt concrete (hereinafter referred to as
As for the asphalt mixture (simply referred to as open-grained asphalt mixture), generally open-grained asphalt concrete or macadam aggregate heated asphalt mixture is used. Also, a room-temperature asphalt emulsion mixture having a high maximum coarse aggregate ratio and a relatively high porosity can also be used. Open-grained asphalt concrete is a heated mixture of coarse aggregate, fine aggregate, filler and asphalt with a synthetic particle size of 15-30% passing through a 2,5 fi sieve.

In addition, the maximum coarse aggregate ratio is high and the porosity is large.

Macadam aggregate heated asphalt mixture is a heated asphalt mixture of coarse aggregate or coarse aggregate with a small amount of filler added, and asphalt is mixed separately into the main aggregate (largest coarse aggregate) and grain aggregate. Either make separate mixtures by laying the main aggregate mixture, then spread the grain aggregate mixture on top and roll them into one, or mix the main aggregate and grain aggregate and mix it with asphalt. A heated asphalt mixture is used, which is prepared by paving the mixture by rolling and rolling the mixture.

This macadam aggregate heated asphalt mixture also has a high maximum coarse aggregate ratio and a large porosity.

The asphalt used as a binder for heated asphalt mixtures having the above-mentioned open particle size is one that is normally used in asphalt mixtures, such as paving asphalt, Trinidad asphalt, semi-prone asphalt,
There are asphalt containing rubber, asphalt containing polymer mixture resin, asphalt containing both rubber and resin, etc. These asphalts contain heavy oil, process oil,
Inslanse oil, tar, anti-stripping agents, anti-aging agents, resins, etc. may also be added. Regarding blending design, manufacturing, paving methods, etc. of heated asphalt mixtures such as particle openness, please refer to
Conventional techniques can be used.

A room temperature asphalt emulsion mixture is obtained by mixing room temperature aggregate or semi-heated aggregate with an asphalt emulsion.

Conventional techniques can be used for mix design, manufacturing, paving methods, etc.

The bituminous emulsion to be sprinkled on the asphalt mixture layer of open particle size is made by emulsifying bituminous materials such as asphalt, tar, pitch, etc., or bituminous materials modified by adding rubber, high molecular polymers, etc. in water. Bituminous emulsions, latex-containing bituminous emulsions made by mixing these with rubber latex or high-molecular polymer latex, and latex-containing bituminous emulsions in which bitumen is emulsified in the aqueous phase of rubber latex, high-molecular polymer latex, etc. , or a mixture thereof. Generally, asphalt emulsion is used. There are various standards for asphalt emulsions (for example, JIS K 2208), and those that fall within these standards and those that do not are used. Asphalt emulsions are mainly cationic or anionic and are used for percolation purposes. A high concentration emulsion with a large amount of evaporation residue is preferred. Most preferred are rubber,
It is a bituminous emulsion (including bituminous emulsion containing latex) modified with a polymer or the like.

Examples of rubbers, polymers, etc. used in the above-mentioned modified bituminous emulsion include the following.

Examples of the rubber include natural rubber and synthetic rubber.

Synthetic rubbers include styrene/butadiene rubber, styrene/isoprene rubber, imprene rubber, butadiene rubber, butyl rubber, chlorobrene rubber, ethylene propylene rubber, EPT rubber, chlorinated polyethylene rubber, chlorosulfonated polyethylene rubber, and styrene/butadiene block polymerization. com, styrene/isoprene block polymer rubber, etc.

These rubbers include modified rubbers containing vinylpylidene groups, carboxyl groups, hydroxyl groups, etc., and these can also be used. Examples of polymers include styrene/butadiene copolymer, styrene/isoprene copolymer, ethylene/vinyl acetate copolymer, polyacrylate, ethylene/acrylate copolymer, vinyl acetate, acrylate copolymer, and styrene/acrylate. These include copolymers, polyurethane, polyvinyl chloride, vinyl chloride copolymers, and vinylidene chloride polymers. In addition, the above bituminous materials include
Resins (eg, rosin, ester gum, terpene resin, petroleum resin, etc.), oils and fats, process oils, anthracene oils, heavy mineral oils, creosote oils, solvents, etc. may also be added. Further, a rubber crosslinking agent such as sulfur powder, zinc white, magnesium oxide, or sodium silicate fluoride may be added together with the above-mentioned filler.

Heated asphalt-coated aggregate is coarse aggregate with a particle size of 13 or less, or aggregate with fine aggregate, fissy, etc. of an equal amount or less than the coarse aggregate, and asphalt (asphalt with rubber, resin, etc.) (including modified asphalt, etc.)
is coated and heated to a temperature of about 100 to 180°C. The amount of asphalt is 0.5 to 6 of the aggregate weight.
．． It is 0% by weight.

Hot asphalt-coated aggregate is typically produced in an asphalt plant. For this coating, in addition to asphalt that has been heated and melted into a liquid state, cutback asphalt or asphalt emulsion can also be used.

The construction method of the present invention is characterized by the step of spreading bituminous emulsion (including modified bituminous emulsion) on the asphalt mixture layer of open grain size, and spreading and integrating heated asphalt-coated aggregate. , Before dispersing the bituminous emulsion, heat the asphalt mixture layer with open grain size etc. with a road heater etc.
A bituminous emulsion is sprinkled over this.

Since the asphalt mixture layer with open grain size is heated in this way, the bituminous emulsion decomposes and evaporates water quickly, and the bituminous emulsion is in contact with the asphalt mixture layer on the surface and upper layer of the asphalt mixture layer with open grain size. The treated bituminous emulsion quickly forms a bituminous material (i or modified bituminous material) and exhibits binding properties. In addition, the amount of bituminous emulsion that flows and accumulates in the lower layer of the asphalt mixed layer is reduced. The bituminous emulsion accumulated in this lower layer also rapidly decomposes into bituminous material (or modified bituminous material). Then, heated asphalt-coated aggregate is laid down on top of this state and is compacted, so that the heated asphalt-coated aggregate fills the voids in the asphalt mixture layer due to the open grain size and becomes integrated. A pavement body is constructed.

Next, the construction method of the present invention will be explained. The figures show one embodiment of the construction method of the present invention. Figure 1 shows a cross-sectional view of a bituminous pavement paved by the construction method of the invention,
The figure shows a cross-sectional view of a bituminous pavement paved using the construction method of the present invention on the surface of an existing bituminous pavement with large road surface friction edges.

In the figure, (1) shows the existing bituminous pavement and roadbed. (2) is a bituminous material such as a tack coat or prime coat made of asphalt emulsion zero, and is applied to the surface of an existing bituminous pavement or roadbed (1).

(3) is an asphalt mixture layer of open grain size, etc., which is provided on the upper surface of the bituminous material (2). (4) is a bituminous material (or modified bituminous material) produced by a bituminous emulsion, and (5) is a heated asphalt coated aggregate. Bituminous material (or modified bituminous material) produced by this bituminous emulsion (4
) fills and seals the voids in the upper layer of the asphalt mixture layer (3) with an open particle size, etc., and binds the aggregate, and the heated asphalt-coated aggregate (5) fills and seals the voids in the upper layer of the asphalt mixture layer (3) with an open particle size, etc. On top, a bituminous material (or modified bituminous material) (4) produced by a bituminous emulsion is firmly bonded. The construction method will be explained step by step.

On the surface of the existing bituminous pavement, a bituminous material (2) such as asphalt emulsion is sprinkled on the roadbed (1) as a tack coat or prime coat. The amount of spraying varies depending on the condition of the substrate. It is less on paved surfaces and more on roadbeds. Second, it may be omitted if there is a risk of breathing or flashing of bituminous materials on the pavement surface. The approximate amount used is 0.4 to 1.2 for permeation asphalt emulsion.
t/rr? It is of a certain degree.

Next, an asphalt mixture (3
) Use a finisher, etc. to level the surface. Then, it is compacted with a roller. In macadam aggregate asphalt mixtures,
The main aggregate mixture and the grain material mixture may be spread twice and then compacted. Various types of rollers can be used as the compaction roller. Usually, it is compacted with tire rollers,
Then, a method of compacting with a macadam roller is used. A predetermined rolling pressure is sufficiently applied to form an asphalt mixture layer (3) with an open grain size, etc.

The asphalt mixture layer (3) having an open grain size is heated with a road heater or the like, and then a required amount of bituminous emulsion is sprinkled on its upper surface. It is desirable that the bituminous emulsion to be sprayed is also heated to 60°C or higher. The amount of spraying is approximately 100-1)
It is about 00-250.

Since the asphalt mixture layer (3) of open particle size etc. is heated, decomposition of the spread bituminous emulsion, evaporation of water, and generation of bituminous material (or modified bituminous material) occur in the upper part of the asphalt mixture layer. It is carried out more sequentially, quickly and uniformly, and there is less accumulation in the lower part of the asphalt mixture layer as in the conventional method. In addition, the bituminous emulsion in the lower layer quickly decomposes, producing bituminous material and exhibiting binding strength. In this way, the bituminous material (or modified bituminous material) (4) produced by the bituminous emulsion not only covers the surface of the asphalt mixture layer (3), such as the open grain size, but also covers the internal surface. Partially fills the void. Then, the asphalt-coated aggregate (5) heated to 120-180°C is subsequently applied to the upper surface. Scatter it, spread it evenly, and compact it with a roller. Tire rollers, macadam rollers, tandem rollers, etc.? Finish by rolling it using This sealing with the top layer of bituminous emulsion and hot asphalt coated aggregate can also be done in two layers.

Next, the features, effects, etc. of the bituminous pavement paved by the construction method of the present invention will be explained.

1) Pave a layer of asphalt mixture with an open grain size that creates a skeleton by interlocking coarse aggregates that are resistant to wear, heat this asphalt mixture layer, and then spread bituminous emulsion and spread asphalt-coated aggregate. They are then compacted and integrated to form a bituminous pavement. Since the asphalt mixture layer is heated, the decomposition of the bituminous emulsion, water evaporation, reduction to bituminous material, and bonding strength are fast, regardless of the season (even in winter, which is unfavorable for bituminous emulsion construction). Construction is possible and good construction is possible.

Even if the bituminous emulsion has a high concentration or contains latex, the decomposition of the bituminous emulsion will not be delayed due to the formation of a latex film, and will decompose uniformly and quickly. Therefore, modified bituminous emulsions containing a large amount of latex can also be used.

Therefore, the modified bituminous material produced by the bituminous emulsion can have a high content of rubber, etc., which cannot be achieved with heat-fused bituminous material.

In addition, since the asphalt mixture layer, such as the open particle size, is heated with a road heater or the like, even if the asphalt mixture layer is formed of a room-temperature mixture, it can have the same physical properties as a heated mixture.

2) The bituminous cladding constructed by the construction method of the present invention has bituminous material (or modified bituminous material) in the upper layer of the asphalt mixture layer, which has a skeleton of interlocking coarse aggregates. Because the heated asphalt-coated aggregate is bonded with optical fibers and sealed, it is resistant to wear caused by spiked tires, tire chains, etc.

It is also watertight. The lower layer has relatively many voids and is filled with bituminous material (or modified bituminous material), making it resistant to reflection cracks. Furthermore, the skeleton is made of interlocking aggregates, and the heated asphalt-coated aggregate is filled and bonded with a modified history backing material binding material, and the lower layer has a relatively high porosity, so it is stable even at high temperatures in summer. It has a high degree of hardness, and there is no bituminous flash or pleating.

In particular, when a modified bituminous emulsion is used as a bituminous emulsion, the above effects are fully exhibited.

Since the construction method of the present invention has the above-mentioned features and effects, it can be used to prevent cracks on pavement where cracks have occurred, instead of leveling and sealing the existing pavement to correct its flatness. It is suitable as a cushion layer or overlay for pavements, as a leveling to restore pavement flatness due to abrasion or subsidence, as a surface layer to prevent shrinkage cracks on cement-based stabilized roadbeds, and as a surface layer that requires wear resistance in winter. be.

Next, the present invention and construction method will be explained with reference to 2.3 Example f.

Example 1 In a cold region, cationic asphalt emulsion PK-
4 (evaporation residue 56% by weight, evaporation residue penetration (25%)
℃) 186) at a ratio of 0.4 cm to the back,
On the top surface, No. 6 crushed stone 57.6% by weight, No. 7 crushed stone 23.0%
weight%, sand 11.4% by weight, stone powder 4.0% by weight and straight asphalt (penetration (25°C) 89)
Open-grained asphalt concrete (approximately 150°C) with a composition of 4.0% by weight is spread at a rate of 8.5 t/100- by a finisher, and then thoroughly compacted with tire rollers and macadam rollers. Next, the open-grained asphalt concrete is heated with a road heater so that the surface temperature of the open-grained asphalt concrete becomes 100° C. or higher. Subsequently, a cationic rubber asphalt emulsion (evaporation residue: 65% by weight, rubber content in the evaporation residue: 5% by weight) heated to 70°C was applied to the top surface.
0 t/100i, and then heated asphalt-coated aggregate (No. 7 crushed stone (particle size 5 to 2.5
m) 70% by weight of aggregate, 26% by weight of river sand, and 4% by weight of stone powder mixed with 3% by weight of asphalt and covered) (approximately 150°C) at a ratio of lt/100-, A bituminous pavement with an average thickness of 3.7 crn was paved by the construction method of the present invention by thorough rolling with tire rollers. Things have been going well since the road was reopened to traffic. - Even though the road has passed through the winter, there is little wear on the road surface and no reflection cracks were observed.

Example 2 Asphalt emulsion PK-41 &: 40/=/100 m' was sprayed onto the asphalt concrete pavement in a cold region, where the road surface had cracks and cracks and had poor flatness. As a leveling seal, rubber-containing dia asphalt (rubber content: 4% by weight, penetration rate (25°C
) 85) using open-grained asphalt concrete (approx. 150°C) at 8.5 t/Zo.

- Spread the material at a ratio of -, then thoroughly compact it with a tire roller and macadam roller. The next day, the open-grained asphalt concrete was heated with a road heater until the surface reached 100%.
℃ or above, and then asphalt emulsion containing anionic rubber latex (nonvolatile content 68% by weight, rubber content in nonvolatile content 10% by weight)'! k 160 t/
100 m', then heated asphalt-coated aggregate (80% by weight of No. 7 crushed stone, 20% by weight of river sand, coated with 2.0% by weight of asphalt) on the top surface (approximately 1
50℃) at 0.8 t/Zo.

- Spread at a ratio of - and compacted with tire rollers and macadam rollers to achieve an average thickness of 3.7 cm with good flatness and excellent abrasion resistance.
A W1 bituminous pavement was obtained. As in Example 1, the road surface was in good condition after the road was opened to traffic; - there were few cracks caused by the winter weather, and no vertical cracks were observed.

Example 3 In a cold region, cationic asphalt emulsion PK-4 (
Evaporation residue 56% by weight, penetration of evaporation residue (25°C)
186) After spraying at a ratio of t 0.4/-,
An open-grained asphalt concrete mixture having the same composition as in Example 1 (approximately 150°C) was placed on the top surface of the mixture (t8.5 t/1).
00m'' with an asphalt finisher, and then thoroughly compacted with tire rollers and macadam rollers.

The next day, while heating the open-grained asphalt concrete with a road heater, a cationic asphalt emulsion (evaporation residue 70% by weight, penetration of evaporation residue (25°C
) 125) heated to approximately 70℃ ft160
Spread at a rate of t/100 m'. Subsequently, 0.7 t/100 m' of heated asphalt-coated aggregate (No. 7 crushed stone coated with 1.5% by weight of asphalt) was applied to this upper surface.
A bituminous pavement with good flatness and excellent abrasion resistance was obtained by dispersing the powder at a ratio of 100% and rolling it with a tire roller.

As in Example 1, the road surface condition was good after opening to traffic, and -
The results were good, with fewer cases of 9 in the winter.

[Brief explanation of drawings]

Figure 1 shows a cross-sectional view of a bituminous pavement paved by the construction method of the present invention, and Figure 2 shows the construction of the present invention on the surface of an existing bituminous pavement with a large road surface 9 A cross-sectional view of a bituminous pavement paved using the method is shown. In the figure,
(1) is the existing bituminous pavement or roadbed, (2) is bituminous material such as tack coat or prime coat with asphalt emulsion, (3) is an asphalt mixture layer with open grain size, etc., and (4) is bituminous material. Bituminous wood produced by blue emulsion, and (5
) is heated asphalt-coated aggregate.

Claims (1)

[Claims] After spreading bituminous material such as asphalt emulsion on the surface of the existing bituminous pavement or roadbed, it is topped with a high ratio of maximum coarse aggregate such as open-grained asphalt concrete, which has a relatively high porosity. The asphalt mixture is spread and compacted to form an asphalt mixture layer, and then the asphalt mixture layer is heated with a road heater or the like, and then a bituminous emulsion is sprinkled on the asphalt mixture layer to form the asphalt mixture layer. The asphalt mixture layer is allowed to partially penetrate into the voids and coated on the surface of the asphalt mixture layer, and then,
A method of constructing a bituminous pavement characterized by laying heated asphalt-coated aggregate on the top surface and finishing by rolling it.