JPH0641906A - Expansible pavement material and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent the separation of a binder and an aggregate by heating and mixing the binder and powdery aggregate, and then by quickly cooling the heated mixture in a powdery state, so that a solidified binder layer is coatedly formed on the surface of the aggregate. CONSTITUTION:A modified asphalt binder 8 in which synthetic resin, rubber, or the like have been mixed in asphalt, and a powdery aggregate 7 are heated and mixed. The heated mixture is quickly cooled in a powdery state, and a solidified binder 8 layer is coated on the surface of the powdery aggregate 7 to form a powdery body (a). In working, the powdery material (a) is filled in a desired place in such a state that the binder 8 on the surface has been slightly melted by exposing to the hot air, or by heating the vessel, or by applying a heated plate. When pressurized, the binder 8 solidifies again, and working is completed. In the case of thick pavement, the working is repeated several times in the laminating method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretchable pavement material used for repairing bridges and roads and a method for manufacturing the same.

[0002]

2. Description of the Related Art A room temperature asphalt mixture which has been widely used in the past is not solidified even when the temperature drops to room temperature because the heated asphalt mixture solidifies with cooling and becomes unusable. The asphalt itself is adjusted with oils such as heavy oil, light oil, volatile oil, etc. and solvents or diluents so that the mixture does not solidify at room temperature.

Therefore, there are the following drawbacks.

[0004] In order to keep the viscosity and fluidity of the mixture within a usable range at room temperature, it is inevitable to mix additives such as oils, so that the quality is remarkably deteriorated.

If the normal temperature composite material is compacted and rolled in a usable state, volatilization and separation of the solvent and the diluent are significantly hindered, and it takes a long time to obtain a high quality road surface material.

[0006] During storage, oils, solvents, and volatile substances are easily separated, and storage for a long time cannot be performed.

The stretchable pavement material (elastic pavement material) used for continuous pavement is generally a special modified asphalt (synthetic resin, rubber, etc. are mixed with the asphalt to improve the original performance of the asphalt. Stuff) and coarse aggregate,
It is a fine pavement material or a mixture composed of inorganic powder, rubber powder, etc., and is a flexible pavement material having properties not found in conventional asphalt pavement materials.

[0008] The modified asphalt used for the stretchable pavement material is required to have a flexible property rich in elasticity, but it does not have a load bearing capacity for supporting the load of a vehicle or the like, and thus an aggregate or the like. To increase the load bearing capacity against compression pressure and at the same time secure the necessary elasticity, and at room temperature, it is a solid or rubber-like solid that melts with heating and exhibits fluidity.

The following method has been proposed as a method of filling and molding the stretchable pavement material in the joint portion, stretchable portion, repaired portion and the like of continuous pavement.

Injection and Casting Molding As shown in FIG. 1, heated aggregate is spread, and a binder that has been heated and melted is poured within a time during which the aggregate does not lower in temperature, and the binder is injected into the aggregate gap. If the layer is thick, repeat this process to thicken the layer.

Premix Injection Molding Premixed heated aggregate and heated molten binder,
Spread the mixture. Further, as shown in FIG. 2, the insufficient binder is injected into the aggregate gap.

Mixing and Filling Molding A mixture in a heated state in which a heated aggregate and a predetermined amount of a binder melted by heating are mixed in advance is spread.

As described above, conventionally, the stretchable pavement material is molded in situ by the following methods. However, each method has the following drawbacks, and satisfactory results cannot be obtained in terms of workability and function of the molded product.

(A) It is almost impossible to adjust the temperature between the aggregate gaps to an appropriate temperature in a work environment on the road where it is difficult to maintain the temperature of the aggregate and is easily affected by the outside air temperature. Therefore, even if the binder heated to an appropriate temperature is poured and injected, it is not expected that the binder is uniformly infiltrated and filled in the aggregate gap as shown in FIG.

(B) The same problems as those in the preceding paragraph occur, and the binder and the aggregate that are heat-mixed decrease in temperature immediately after spreading, so that the molded product is solidified while leaving voids as shown in FIG.

(C) The binder and aggregate are separated from each other for the following reason, and a uniform molded product cannot be obtained. Typical asphalt-based paving mixes have a binder ratio of 5-6%
Is. In the stretchable pavement material for satisfying this type of stretchability function, it is necessary to considerably increase the content of the binder to about 15 to 20%. Therefore, the molded product undergoes phase separation due to the difference in specific gravity between the binder and the aggregate before cooling and solidification, and the aggregate sinks, so that a uniform molded product as shown in FIG. 5 cannot be obtained.

(D) The heated mixture produced in the plant causes a temperature drop during transportation to the site of use, so that the transportation range is limited. Therefore, it is necessary to arrange manufacturing plants in various places and establish a system to meet demand.

(E) Since the temperature of the heated mixture brought into the site lowers, it is difficult to obtain a predetermined pavement layer unless it is laid and compacted for a predetermined time.

(F) If the construction must be interrupted during transportation or during standby due to sudden rainfall, the heated mixture must be discarded, and even if it is reused, it will be more costly than a new production. Is invited.

(G) In the case where the heating mixture is supplied during a period of unstable demand (winter period in cold regions or snow regions),
Especially in the case of a small amount, it is uneconomical, and in fact, the operation of the plant is often stopped.

(H) The heated mixture solidifies with cooling.
Once the heated mixture is produced, even if the temperature is prevented from lowering with a heat-retaining device or the like, the deterioration and deterioration of the asphalt will proceed, and the storage will be within a few days.

From the above, as a method for obtaining a uniform molded product, even if the mixed material is sufficiently homogeneously mixed by a mixer or the like, the mixing is interrupted or the interphase separation is performed immediately after the expansion portion is filled. start. Separation of aggregate and binder
The drawback is that the amount of binder coated on the aggregate is extremely small. Regarding the elasticity of the stretchable pavement, the stretchable function of the pavement cannot be exerted unless a stretchable binder having a constant thickness is secured at intervals between aggregate particles.

From these points of view, it is desired to select the methods (1) to (3) as a method for avoiding the above-mentioned separated state, but in addition to the above-mentioned problems, there is a drawback that only a very small scale construction can be performed.

This problem was found to be due to the fact that the aggregate and binder tend to separate due to the difference in specific gravity before the mixture heated and mixed with a predetermined composition is cooled and solidified, and the mixture in a uniform heated and mixed state is identified. The present invention was completed by focusing on the point that if an appropriate amount is rapidly cooled and solidified in an extremely short time to solidify, a predetermined amount of binder adheres to the aggregate while maintaining a predetermined thickness and solidifies without separation. did.

[0025]

The gist of the present invention will be described with reference to the accompanying drawings.

The binder 8 and the granular aggregate are heated and mixed,
The heat-mixture 6 is rapidly cooled in a granulated state to form a solidified binder layer on the surface of the granular aggregate to form a stretchable pavement material.

Also, a modified asphalt binder,
The present invention relates to a method for producing a stretchable pavement material, which comprises heating and mixing various coarse and fine aggregates 7 and rapidly cooling the heated mixture 6 in a granulated state.

[0028]

The binder layer on the surface of the granules is softened and melted by heating the mixture, which is in the form of granules at room temperature, by an appropriate method. In this way, if the binder layer of the whole granules is spread and molded in a softened and melted state, the granules are solidified in a state where they are melt-bonded to each other, so that the defect that the binder and the aggregate are separated is eliminated, Figure 6
As described above, it is possible to obtain a molded product that is molded and solidified by a mixture in which a uniform binder is mixed.

[0029]

[Example] A modified asphalt binder that improves the original performance of asphalt, which is a mixture of asphalt with a synthetic resin, rubber, etc., and various kinds of aggregates such as coarse aggregate and fine aggregate are mixed by heating (binder composition is 15 ˜25%), and the heated mixture is quenched in the granulated state.

For example, an appropriate amount of the above mixture 3 heated to 140 ° C. to 200 ° C. is dropped onto a metal net 2 having a mesh 1 having a desired grain size. Since the mixture 3 drops downward through the mesh 1, the size of the mesh 1 is selected and set to a desired size so that the mixture 3 drops to the lower water tank 4 in a desired granular size.

Water 9 is sprinkled in this water tank 4 and fine particles 5 of a mineral substance such as tankar are suspended and placed. The heated mixture 6 falling in a desired size of granules is instantly cooled when dropped into the water 9, and the binder 8 attached to the surface of the aggregate 7 is solidified by the rapid cooling action, so that the binder 8 does not flow down. In addition, since the fine particles 5 of the mineral substance are sprinkled on the outer surface, a desired-sized granular material a which does not adhere to each other can be obtained.

Since this granular material a can be stored at room temperature, it can be marketed in a bag. At the time of construction, hot air is applied, it is heated in a container, or a hot plate is applied to fill the desired portion in a state where the binder 8 on the surface is slightly dissolved, and the binder 8 is solidified again when pressure is applied. Is completed. In the case of thick construction, it may be repeated several times in a laminated system.

The pavement of the present invention exhibits the following features.

Since it is a granular mixture, heat is easily absorbed and a heated mixture can be obtained in a short time.

Since it can be stored at room temperature, a large amount of stock can be obtained, which is effective during periods of unstable demand.

Even if the granular mixture is transported to the site, the unused one is a stable granular mixture, so that there is no waste such as discarding the surplus amount on site unlike the conventional product.

Since the same material as the heated mixture is cooled and granulated, it is also very effectively used as a road surface repair material (repair, overlay, etc.).

The production is simple, suitable for mass production, and the elastic pavement material can be provided at low cost.

In this granular stretchable pavement material, the binder is adhered in a substantially uniform thickness, and the binder is dissolved again only by heating, and when pressed, they are adhered and solidified to each other to form a pavement layer having excellent stretchability. Form.

[0040]

As described above, the present invention provides a granular mixture in which a binder is adhered in a substantially uniform state by rapidly cooling the mixture, which is heated and mixed in a uniform mixed state, in a granular state.
A stretchable pavement material in a granular form that does not adhere to each other at room temperature is obtained. If this granular mixture is heated, the binder layer on the surface is softened, and if pressure is applied in this state, a pavement having excellent stretchability will be formed.

[Brief description of drawings]

FIG. 1 is an explanatory view of a conventional injection and casting method.

FIG. 2 is an explanatory diagram of a conventional premix injection molding method.

FIG. 3 is an explanatory view of a conventional mixture filling and molding method.

FIG. 4 is a cross-sectional explanatory view of a pavement portion constructed by the method of FIG.

5 is a cross-sectional explanatory view of a pavement portion constructed by the method of FIGS. 2 and 3. FIG.

FIG. 6 is an explanatory cross-sectional view of an ideal stretchable pavement portion.

FIG. 7 is a cross-sectional explanatory view of a stretchable pavement part constructed using the stretchable pavement material of the present invention.

FIG. 8 is an explanatory view showing the manufacturing process of the present invention.

FIG. 9 is a cross-sectional view of a granular material.

[Explanation of symbols]

 6 Heated mixture 7 Aggregate 8 Binder

Claims (2)

[Claims] 1. A binder and a granular aggregate are heated and mixed,
A stretchable pavement material, characterized in that the heated mixture is rapidly cooled in a granulated state to form a solidified binder layer on the surface of the granular aggregate. 2. A modified asphalt binder and a coarse
A method for producing a stretchable pavement material, which comprises heating and mixing a variety of fine aggregates, and rapidly cooling the heated mixture in a granulated state.