JPH0656002B2 - Room temperature composite material for repair and repair method of bituminous pavement using it - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a room temperature composite material for repair, which is suitable for repairing a crack part of a bituminous pavement and regeneration and improvement of a surface layer part of the bituminous pavement, and a bituminous pavement using the room temperature composite material. It relates to the repair method.

When bituminous pavement is used for traffic and weathering causes it to crack on the road surface and cause subsidence, potholes, unevenness, rutting, etc., the serviceability of the pavement deteriorates. There is. When the road surface is slightly damaged, proper surface treatment will make it economical and easy to construct, and will make the pavement last longer. However, when the damage further progresses and the serviceability deteriorates, the surface treatment is no longer sufficient, and overlaying of thin layer pavement or thicker pavement is carried out, or replacement of damaged points and reclaimed pavement are performed.

Replacement involves the disposal of waste pavement material because the pavement is broken and replaced, and it is difficult to secure the disposal site and the waste pavement material itself can be effectively used as a pavement material. The number of construction methods is increasing.

The methods of reusing waste pavement materials are roughly divided into those that are recycled into roadbed materials and those that are recycled into the surface layer, base layer, etc. as an asphalt mixture, and both of these methods are the plant method and the road method. There is.

Among these regeneration methods, there is a method of regenerating and improving the surface layer portion of the bituminous pavement by a road method, and various methods have recently been used. For example, a method of heating a road surface that is fatigued and cracked, or a road surface that has a defect such as rutting, scraping the surface layer, crushing and mixing, spreading, rolling, and regenerating, , A new hot asphalt mixture is laid and leveled and regenerated by rolling, or a new hot asphalt mixture is laid and mixed on a road surface heated and excavated to crush the surface. There is a surface layer reclaiming method such as a method of reusing it by rolling it.

If the surface layer of the bituminous pavement is damaged and needs repairing, the asphalt oil in the asphalt mixture (hereinafter referred to as the mixture) that constitutes the surface layer is volatilized during pavement use and the asphalt is hard. As a result, the overall binding strength is reduced, and in many cases the amount of asphalt is substantially insufficient.

For such bituminous pavement, the road surface is heated by a road heater, the surface layer is scratched, mixed and spread, and when the surface layer is regenerated by rolling this, the asphalt in the asphalt mixture of the surface layer is heated by the heater. As it becomes considerably harder during binding, the binding strength of asphalt is further reduced.
Further, the grain size of the asphalt mixture that has been scratched is finer than that of the new heated asphalt mixture, and in particular, the size and amount of the coarse aggregate, which is the main aggregate, are reduced. Therefore, the regenerated pavement has a shortage of binder and a shortage of main aggregate, and thus the stability and durability are lower than those of the new asphalt mixture. In order to make up for the shortage of the asphalt content and the oil content of the asphalt, a method of adding and mixing an asphalt emulsion or a softening agent to the asphalt mixture that has scratched the surface layer, spreading it, rolling it, and regenerating it is also used. In this case as well, the grain size of the aggregate is not improved, so that the stability is not sufficient even after the regeneration. Therefore, a new hot asphalt mixture is laid on top of this and leveled, or a new hot asphalt mixture is mixed with the asphalt mix that has scratched the surface layer and spread and leveled. A method to regenerate is implemented. Since they use a new hot asphalt mixture, they are improved in stability and durability like new hot asphalt pavement. However, since heated asphalt mixture is used, good construction cannot be performed when the temperature drops, so temperature control is required from transportation to construction, and recycled pavement is similar to heated pavement and construction is not easy, and cost is low. It becomes expensive and not economical. In particular, it is difficult to apply for small-scale repairs and temporary repairs.

Therefore, repairing bituminous pavement, especially rehabilitation and improvement of the surface layer, can be done easily and easily, and it can be applied regardless of the season regardless of the season, even if the area is large or narrow, and the renovated pavement is new. There is a demand for a method that can be regenerated into a bituminous pavement having stability and durability like the heated asphalt mixture pavement.

The present invention responds to such a demand, and a new repairing room temperature mixture material suitable for repairing a crack part of a bituminous pavement and regeneration improvement of a surface layer part, etc. Thus, the present invention provides a method for repairing bituminous pavement, which is effective in preventing the occurrence of cracks and which provides highly stable bituminous pavement.

One of the present invention is characterized in that coarse aggregate of a single particle size and oil, asphalt emulsion containing a softening agent and the like is mixed to asphalt-coat the coarse aggregate, and that the surface is further coated with asphalt-coated sand. The present invention relates to a room temperature composite material for repair.

Another one of the present invention is to heat the repair surface of an existing bituminous pavement with a load heater to soften the required depth from the surface of the bituminous pavement, and then to the upper surface of the above repairing room temperature mixture material. Lay out the required amount, then stir up the bituminous pavement that has been softened using an on-road mixer, crush it, mix it with a repairing room temperature mixture, lay it out, and then roll compact it. It is related to the method of repairing the bituminous pavement, which is a feature.

The normal temperature composite material for repair of the present invention will be described.

As the coarse aggregate having a single grain size, a coarse aggregate having a single grain size, which is a hard aggregate used for road crushed stones and roads, is used. The particle size range is from 30 mm to 2.5 mm, preferably 25 mm to 5 mm. For example, for JIS A 5001 road crushed stone, S-20 (No. 5) crushed stone (particle size 20 to 13 mm), S-13
(No. 6) Crushed stone (particle size 13-5 mm). This particle size range does not necessarily have to meet this standard. For example,
It may be 20 to 10 mm, 10 to 5 mm, 25 to 13 mm, or the like.

Oil content of asphalt emulsion containing oil, softener, etc.,
The softening agent and the like are as follows. Mineral spirits, kerosene, naphtha, xylol, solvent naphtha, heavy naphtha, etc.
Lubricating oils, process oils, heavy oils, other mineral oils, tars, oils and fats, polymerized oils, fatty acid pitches, creosote oils, anthracene oils, pine oils, pine oils, plasticizers, liquid resins, liquid rubbers and the like.

Asphalt used for the asphalt emulsion includes asphalt used for paving and asphalt used for the asphalt emulsion. These are petroleum asphalt such as straight asphalt, semi-blown asphalt, propane deasphalted asphalt, blown asphalt, and lake asphalt (natural asphalt), and these are used alone or in combination. In addition, rubber, synthetic polymer,
Asphalt modified by appropriately adding a resin and the like (for example, asphalt with rubber, asphalt with resin, asphalt with rubber and resin) is also used.

Asphalt emulsions containing oils, softeners, etc. are oil-in-water type asphalt emulsions obtained by emulsifying the above asphalt with oils, softeners, etc. in water, or asphalt emulsions obtained by emulsifying the above asphalt in water. ,
Examples thereof include those in which a softening agent or the like is dispersed by post-addition and those in which both of them are used in combination. Further, an asphalt emulsion containing these oil components, a softening agent and the like (hereinafter referred to as a special asphalt emulsion) to which rubber latex, high molecular polymer latex, synthetic resin emulsion and the like are added can also be used.

As the special asphalt emulsion, an asphalt emulsion obtained by emulsifying a soft asphalt similar to that containing oil, a softening agent and the like in water can also be used.

The special asphalt emulsion used in the present invention is excellent in mixing property with aggregates, particularly coarse aggregates, and has excellent covering property to aggregates, is quickly decomposed, and has good adhesiveness and water resistance of the asphalt film coated on the aggregates. Those with excellent properties are preferable. The special asphalt emulsion has the characteristics that the asphalt coating decomposed and coated on the aggregate is soft due to the small amount of residual oil and softener, and the coarse asphalt-coated aggregate has a workability that can be spread evenly at room temperature. Have. In general, asphalt emulsions are known to be anionic, cationic, nonionic, clay-based and the like depending on the type of emulsifier, but as the special asphalt emulsion, anionic or cationic ones are preferred.

The amount of oil, softening agent, etc. in the special asphalt emulsion is usually within the range of 3 to 20% by weight with respect to the asphalt, although it depends on these types and types of asphalt.

The asphalt-covered sand is asphalt-coated with fine aggregate (particle diameter: 2.5 mm or less), for example, river sand, sea sand, mountain sand, silica sand, sintered sand, iron sand, and foundry sand. These are, for example, a heat-mixing-type asphalt plant, in which heated sand and heated and melted asphalt (for example, straight asphalt) are heated and mixed (usually the amount of asphalt is
(2 to 3% by weight of sand) It is one that has been kept at room temperature and does not form a lump at room temperature, and is dry like dry sand.

The room temperature composite material for repair of the present invention is produced, for example, as follows.

Single-grain coarse aggregate (for example, No. 5 crushed stone or No. 6 crushed stone) and special asphalt emulsion are mixed at room temperature using a pug mill or the like. At this time, the amount of the special asphalt emulsion is about 5 to 9% by weight of the coarse aggregate by converting the evaporation residue into 60% by weight. Then, a mixture material having a soft asphalt coating and good meat paste is manufactured. Subsequently, asphalt-coated sand is added to this mixture at room temperature at a rate of 10 to 25% by weight of the mixture and mixed and coated to obtain a single-grain repair room-temperature mixture. This single-granular room-temperature mixture material is a state in which coarse aggregate is coated with soft asphalt having good glutinousness, and then covered with asphalt-coated sand. Therefore, like a single-grain aggregate, it can be easily spread and spread.

The features of this room temperature composite material for repair are as follows.

1) Since it is a room temperature type, it can be prepared. It can also be packed in bags.

2) Even without plant mixing, compound materials can be manufactured by soil mixing such as shovel.

3) Since the surface of the repairing room temperature composite material is wrapped with asphalt-coated sand, the respective composite material particles are in a single particle state without being bonded to each other. Therefore, workability such as spraying and spreading is good.

4) The asphalt coating that covers the coarse aggregate of the repairing room temperature mixture is thick and soft, so when it is mixed with the asphalt mixture that has been crushed by scratching the surface layer of the existing bituminous pavement, Also, even if the mixing ratio is high, it is well-accepted, and the density tends to appear when rolled. In particular, the asphalt mix crushed by heating the existing bituminous pavement with a road heater, etc. and crushing it is heated and mixes very well when mixed with the repairing room temperature mix, and the asphalt mix is rough. While replenishing the aggregate to improve the particle size of the aggregate, the asphalt of the asphalt mixture and the asphalt of the normal temperature mixture for repair are well compatible, and the lack of oil content of the asphalt of the asphalt mixture is complemented to become an integral part of the asphalt mixture. Since the asphalt can be rejuvenated, it is possible to create a pavement with high density and stability that is unlikely to cause cracks.

As described above, since the room temperature mixture for repair of the present invention has excellent features and effects, it can be effectively used for the following purposes.

1) As a supplementary material for the partial repair of existing pavement cracks.

2) As an improved recycled surface layer by mixing with pavement waste.

3) As a material for spraying on the bituminous material that has been sprayed for partial crack sealing in the existing pavement before overlaying or surface treatment and rolling while heating with a road heater.

4) As an improved material for the road surface surface recycling method.

5) As a filler to prevent re-cracking after heating and cutting with a load heater for vertical crack repair.

Next, a method of repairing bituminous pavement according to the present invention using the above-described repairing room temperature mixture will be described with reference to the drawings. 1 to 4 show the outline of regenerating and improving the surface layer portion of the existing asphalt pavement where there are partial cracks, subsidence, potholes, etc. by the method of the present invention by using the normal temperature mixture for repair according to the construction order. It is shown in a sectional view. In the figure,
1 is the surface layer of the existing asphalt pavement, where cracks, subsidence, and potholes have partially occurred. Reference numeral 2 is an infrared type load heater. Reference numeral 3 denotes a portion in which the surface layer portion 1 is heated by the load heater 2 to be heated and softened. 4, 4 ...
... is a room temperature mixture for repair. Reference numeral 5 designates a mixture of the surface layer 1 which has been softened by heating and a normal temperature mixture for repairing 4, 4 ...
Mix and spread evenly, then roll and shape 6
Is a seal coat layer.

FIG. 1 shows a state of existing bituminous pavement before carrying out the repairing method of the present invention. In the method of the present invention, as shown in FIG. 2, first, the surface layer portion (for example, dense grain Ascon 13F type) 1 of the existing bituminous pavement is heated by the load heater 2 to heat and soften the required depth thereof. For example, it is heated by an infrared type road heater for about 5 minutes to heat and soften a depth of 3 to 4 cm.
The temperature of this part rises to an average of about 150 ° C.

Then, as shown in FIG. 3, a required amount of the repairing room temperature mixture 4 is spread on the heat-softened portion 3 and leveled. Since the repairing room-temperature mixture 4 is in the form of a single grain, it is easy to spread the aggregate. The repaired room temperature mixture 4 is generally of No. 5 crushed stone type. When the area of the repair area is small, the repaired room temperature mixture can be laid by a rake or the like and spread evenly. If the area is large, spread it using a spreader. The repaired room temperature composite material 4 laid evenly is preheated by the heat of the heat-softened portion 3 of the surface layer portion 1.

Then, using a suitable on-road mixer, the heat-softened portion 3 of the surface layer portion 1 is scratched and the repairing room temperature mixture 4 is mixed with the scratched mixture and spread. As the on-road mixer, there is a stabilizer, but a simple mixer such as an improved tiller may be used. Since the heat-softened portion 3 of the surface layer portion 1 is heat-softened, it can be easily scratched. At the same time as this scratching, the room temperature mixture for repair is mixed. Then, the mixed mixture is soft as for the asphalt of the room temperature mixture for repair, and is further spread by the heat of the scraping mixture to form a well-mixed heated mixture. If the surface is made flat and compacted sufficiently by roller compaction, a pavement with improved regeneration is completed. If necessary, such as when the season is winter or heading for winter, or when traffic conditions are severe, apply a seal coat on top of this, or reheat with a load heater without seal coat and then roll the roller. Complete the pavement by compacting it sufficiently. FIG. 4 shows this state.

In the above process, when the crack width of the surface layer is wide and deep,
It is also possible to remove the scraped mixture on the side and fill the crack with a sealing material, or to remove the first mixture on the side and then heat it a second time to deepen the heating and softening depth.

For the seal coat, a method of spraying an asphalt emulsion and then spraying sand or asphalt-coated sand on it is used. Reheating from the seal coat to the load heater and rerolling pressure from the rollers are usually unnecessary. However, in winter, road surface freeze-thawing and abrasion are severe.

When the surface layer portion is regenerated and improved by the method of the present invention, the finished thickness of the portion is increased by the amount of the normal temperature composite material for repair used. The composite material of the regenerated and improved portion is not simply thicker than the conventional composite material but has a coarser particle size than that of the conventional composite material and has a higher stability due to the meshing effect of crushed stone. Regarding the asphalt used as the binder, the hard asphalt lacking the oil content in the conventional mix is mixed with the soft asphalt used as the repairing room temperature mix to regenerate good quality asphalt. Since the mixed mixture is rolled in the form of a heated mixture, cracking is less likely to occur, and a pavement having high density and stability is formed.

By the surface repair, thin layer pavement, overlay and the like on the bituminous pavement having the surface layer regenerated and improved by the repair method of the present invention, the durability and serviceability of the pavement are further improved.

The invention will now be described in a few examples.

Example 1. Pugmill crushed stone for road S-20 (No. 5) (particle size 20 to 13 mm)
To 100 parts by weight, 6.5 parts by weight of a special asphalt emulsion for cationic mixing (containing 60% by weight of evaporation residue, about 9% by weight of process oil, creosote oil and white kerosene) was added and mixed. If the special asphalt emulsion covers crushed stones, decomposes it, and water is released and the asphalt film becomes sticky, the hot mix type asphalt plant heat-mixes river sand and straight asphalt (2.5% by weight of sand) at room temperature. 15 parts by weight of the asphalt-coated sand is added and mixed to coat the crushed asphalt-coated stone to obtain the single-grain normal temperature repair material of the present invention for repair.

Table 1 shows the aggregate particle size of a mixture prepared by mixing this repairing room-temperature mixture with a mixture of ascon on the existing bituminous pavement (a fine grain 13F) at a weight ratio of 1: 1. Shown in.
Further, a Marshall stability test of this mixed mixture was conducted.
A mixture of oystered mixture heated to 150 ° C was mixed with a repairing room temperature mixture, and a specimen was prepared by curing both sides with 50 times, and tested by a conventional method. This test result shows a density of 2.25
8, Marshall stability 895kg, flow value 32.

Example 2. Pugmill crushed stone for road S-13 (No. 6) (particle size 13-5 mm)
To 100 parts by weight, 7 parts by weight of a special cationic asphalt emulsion for mixing as in Example 1 was added and mixed to make an asphalt-coated crushed stone, and then 20 parts by weight of the same asphalt-coated sand as in Example 1 was added and mixed. As a result, a single-grain repairing room temperature composite material of the present invention is obtained.

Table 2 shows the aggregate particle size of a mixture obtained by mixing the repairing room temperature mixture with the same scraping mixture as used in Example 1 (dense granule 13F) at a weight ratio of 1: 1. . Further, a Marshall stability test of this mixed mixture was conducted. A mixture of oystered mixture heated to 150 ° C was mixed with a repairing room temperature mixture, and a specimen was prepared by curing both sides with 50 times, and tested by a conventional method. The test results were a density of 2.235, a Marshall stability of 677 kg and a flow value of 36.

As shown in Examples 1 and 2, by mixing the repairing room temperature mixture with the conventional scraping mixture, the aggregate particle size was remarkably improved, and the density and marshall stability were also improved. Shows.

Example 3. Pugmill 100% by weight of crushed stone for road S-20 (No. 5), special asphalt emulsion for cationic mixture (evaporation residue 58% by weight, raw asphalt containing 3% rubber straight asphalt Penetration (25 ° C) 182 , Containing about 9% by weight of lubricating oil, anthracene oil, kerosene, etc. in the emulsion) 6.5
When the special asphalt emulsion covers the crushed stones and decomposes and water is released to give tackiness to the asphalt coating, 20 parts by weight of the asphalt-coated sand similar to that in Example 1 is added and mixed. The coated normal temperature composite material for repair of the present invention in the form of single particles is obtained.

Example 4. In the soil, 6.5 parts by weight of the same special asphalt emulsion as in Example 1 was added to 100 parts by weight of crushed stone of S-20 (No. 5) similar to that of Example 1, mixed with a shovel loader, and the crushed stone was coated with the special asphalt emulsion. . The special asphalt emulsion decomposes,
When the water content comes out and the tackiness of the asphalt comes out, 22 parts by weight of the asphalt-coated sand similar to that used in Example 1 is added and mixed by a shovel loader to obtain a single-grain repair normal temperature mixture.

The above-described repairing room temperature mixture materials of Examples 1 to 4 can be stored in bulk, but bagging is convenient for partial repair of the surface layer of the existing bituminous pavement.

Example 5. Surface layer of asphalt pavement with cracks, subsidence, potholes, etc. on the existing surface (Dense particle size Ascon 13F type 5
Heating the repaired part in (cm thickness) with an infrared type road heater. 3 ~ 4cm from the road surface by heating for about 5 minutes
It softens by heating to an average temperature of 140-150 ℃.

On top of this, the normal temperature composite material for repair of Example 1 is laid at a rate of 50 kg per 1 m ^{2 and} leveled. Then, an upper-layer thickness of 4 cm in the surface layer of conventional pavement is scratched by a road mixer with an improved tiller, mixed with a room temperature mixture for repair, laid and leveled, and sufficiently compacted by roller compaction. Next, asphalt emulsion PK-2
Scatter 1.0 / m ² and sprinkle 7 kg / m ^{2 of} coarse sand on it. The surface is heated by a load heater and rolled to finish. The finished thickness of the surface layer improved by this regeneration is 6
cm, which is 2 cm thicker than the conventional road surface. This refurbished and improved bituminous pavement was soon opened to traffic and passed the winter, but there were no cracks, little wear, and no flow.
It is in good condition.

[Brief description of drawings]

The figure shows a method for repairing bituminous pavement according to the present invention.
Fig. 1 is a sectional view of the bituminous pavement before repair, Fig. 2 is a sectional view of the bituminous pavement showing the heating state, and Fig. 3 is a history showing a state in which a repairing room-temperature mixture is spread and leveled. 4 is a sectional view of the blue pavement body, and FIG. 4 is a sectional view of the bituminous pavement body after repair. The reference numerals in the figure are as follows. Reference numeral 1 is a surface layer portion, 2 is a load heater, 3 is a softened surface layer portion, 4 is a room temperature composite material for repair, 5 is a shaped portion, and 6 is a seal coat layer.

Claims (2)

[Claims] 1. A repair, characterized in that a coarse aggregate having a single particle size and an asphalt emulsion containing an oil component, a softening agent and the like are mixed to coat the coarse aggregate with asphalt, and the surface thereof is further coated with asphalt-coated sand. Room temperature mixture. 2. A repair surface of an existing bituminous pavement is heated by a load heater to soften a required depth from the surface of the bituminous pavement, and then coarse aggregate is added to the top surface with oil, a softening agent and the like. Asphalt coating with asphalt emulsion, and further spread the required amount of repairing room temperature mixture with asphalt-covered sand on the surface, and then spread by softening bituminous pavement and repairing room temperature mixture. A repairing method for bituminous pavement, which is characterized by leveling and then rolling and shaping.