JPH01230801A - Construction of adiabatic pavement structure - Google Patents

Abstract

PURPOSE:To obtain a pavement structure having a supporting force as well as effective adiabatic property, light weight property and elastic property by constructing a mixture layer comprising forming particles, binder and aggregate as essential components, with the ratio of liquid contained in the mixture to the mixture less than the fluidization point. CONSTITUTION:On a subgrade 1, a forming particle mixture layer 6 mixed with hydraulic material and aggregate is applied and an upper layer roadbed 4 comprising crushed stone, ballast, sand and the like are applied thereon. Next, on the upper layer roadbed 4, there is applied a surface layer 5 of asphalt concrete or the like. The forming particle mixture layer 6 is composed of forming particles, binder and aggregate and has a ratio of liquid contained in the mixture to the mixture less than the fluidization point. As the forming particle, there is used synthetic resin forming particle, inorganic hollow material or the like. There is used hydraulic material, asphalt system, resin system or the like as the binder. Thus, it is possible to prevent freezing on a road or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for constructing a heat insulating pavement structure for roads, playgrounds, tennis courts, etc., and more specifically to an i! ! ! The present invention relates to a method for constructing a heat-insulating pavement structure that can exhibit elasticity and elasticity.

(Prior Art) A frost heaving prevention construction method for roads, etc. is a construction method that prevents damage to the ground due to frost heaving phenomena in winter on roads, playgrounds, tennis courts, etc. in cold regions.

Various methods have been proposed to prevent frost heaving on roads, etc.

For example, a replacement method, a heat insulation method, a chemical treatment method, a water-blocking method, etc. are known.

Among these, the replacement method involves replacing the subgrade soil within the freezing depth with a material that is less likely to cause frost heave, and has problems such as rough excavation work and disposal of residual soil, and also requires the addition of cryogens such as calcium chloride. Methods such as chemical treatment methods or methods of lowering the groundwater level by installing drainage channels have various drawbacks, such as the large-scale construction methods and the lack of effectiveness unless carefully carried out. This cannot be said to be a construction method for a thermally insulated pavement structure.

On the other hand, the insulation method is a construction method in which a heat insulating layer is provided between the surface layer and the ground or subgrade to prevent outside air temperature from being conducted into the ground, thereby preventing moisture in the ground from freezing.

This construction method is disclosed in Japanese Patent Publication No. 51-41765, Japanese Patent Publication No. 55-44202, Japanese Patent Publication No. 61-28042.
There is a method of forming a heat insulating layer using a foamed plastic molded plate, as proposed in Japanese Patent Publication No. using this method(
Well, after laying a sand layer on the roadbed or ground dug 10cm to 100cm underground, foamed plastic molded boards are laid down, sand is spread on top of this again, and aggregate such as crushed stone and roadbed material are placed on top of this. It is used to spread and finish the pavement with asphalt, concrete, etc.

However, in this method, the foamed plastic molded plate is prone to misalignment due to 11TfJ during construction and is susceptible to damage due to the corners of crushed stones, so it is essential to provide a sand layer on the molded plate.

In addition, it requires cutting and joining of foamed plastic molded plates to match the shapes of drainage ditches, exposed piping, manholes, etc. in the excavated roadbed, making the process extremely complicated.

Furthermore, if only the insulation effect is considered, the closer the foamed plastic molding is placed to the surface, the better the effect will be. However, near the pavement surface, large stresses occur due to traffic loads and other factors. Since the load-bearing capacity of the foamed plastic molded body is extremely small, the current situation is that the foamed plastic molded body is placed on the lower surface of the upper roadbed and/or the lower roadbed at the expense of the heat insulation effect.

Other insulation methods include the method using asbestos, glass wool, cellulose fiber, etc. as a heat insulating material (M-Kokoku No. 62-8561, etc.), or the method using expanded polystyrene beads (Japanese Patent Publication No. 43-2025, etc.). Special Publication No. 57-77701 etc.) have been proposed,
Furthermore, cement mixtures containing expanded styrene beads have also been proposed (for example, Japanese Patent Publication No. 42-2071).
Publication No. 9, Special Publication No. 47-28683, Special Publication No. 1977
-11725 Publication, Special Publication No. 50-36853,
Special Publication No. 54-11814, Special Publication No. 62-3699
Publication No. 4, etc.). However, in these conventional construction methods, because the cement mixture and foam particles are mixed with poor affinity, or because the cement mixture is fluid, when the cement mixture and foam particles are mixed in a mixer, ,In order to form a pavement surface with good compressive strength, in order to form a pavement surface with good compressive strength, the cement mixture and foamed particles separate due to the difference in specific gravity and the buoyancy force acting on the foamed particles, not only during transportation but also on site. This method requires the addition of binders, admixtures, etc., and has the problem of requiring complicated work steps.

(Problems to be Solved by the Invention) In view of the above-mentioned problems, as a result of intensive studies, the present invention provides a simple method using foamed particles that has a supporting capacity as pavement and is effective. The object of the present invention is to provide a construction method that can inexpensively obtain a pavement structure that has good heat insulation properties, light weight, and elasticity.

(Means for Solving the Problem) The first invention is to provide 61i of a h1 compound layer on the surface to be paved, which has foamed particles, a binder, and an aggregate as essential components, and has a liquid content ratio below that of fluidization. The second invention is a method for constructing a heat insulating pavement structure characterized by spreading foam particles all over the surface to be paved, mixing the foam particles with at least a binder, aggregate and/or native soil supplied separately, and paving. A third invention is a method for constructing a heat insulating pavement structure, characterized in that a resin bag filled with a certain volume of foamed particles is spread on the surface to be paved, and at least a binder and aggregate, which are separately supplied, are spread on the surface to be paved. A method for constructing a heat-insulating pavement structure characterized by breaking and kneading resin bags at the same time and paving them. This is a method for constructing a heat insulating pavement structure, characterized by paving the blocks by paving them together with at least a binder and aggregate, which are separately supplied, while destroying the blocks.

The insulating pavement structure of the present invention can be effectively constructed as a roadbed, roadbed, or surface layer.

FIG. 1 is a cross-sectional view showing an example of a road paving structure according to the present invention, and FIG. 2 is a cross-sectional view showing an example of a conventional road paving structure in comparison thereto.

In the conventional one-step replacement construction method of insulating pavement structure shown in Figure 2, 60 to 150 cm of mountain sand, etc. After installing the frost heaving control R (2) made of fine granules, the lower road is made of 10 to 40 cm of gravel, mountain gravel, etc.! (
An upper roadbed (4) made of a mixture of crushed stone, gravel, sand, etc. of 31 cm and 10 to 50 cm is constructed, and then a surface layer (5) of asphalt concrete or concrete is constructed on top of it.
is formed.

On the other hand, in the pavement configuration example of the present invention shown in FIG.
10~30cm on top of the roadbed (1) which has been excavated about 50cm.
After providing the foamed particle mixed layer (6), which is a mixture of about m of hydraulic material and aggregate, the upper base course (4) and the surface layer (
5) Form.

The method of forming a specific heat insulating layer of the present invention requires less excavation per depth than conventional replacement methods and foamed plastic molding methods, which not only simplifies the work, but also solves the problem of disposal of leftover soil. There are advantages such as reduction in

In the present invention, as the binder, hydraulic substances, asphalt-based binders, and resin-based binders are preferably used.

Hydraulic substances include portland cement such as white cement and early-strengthening cement, mixed cements such as blast furnace cement, silica cement, flyanche cement, various cements such as special cements such as alumina cement and ultra-fast hardening cement, gypsum, Examples include lime.

As an asphalt-based binder, one or more of straight asphalt, blown asphalt, flopane asphalt, cutback asphalt, tar, tar pitch, fatty acid pitch, tall oil pitch, heavy mineral oil, etc. may be mixed. Examples include asphalts and asphalt emulsions thereof.

As the resin binder, conventionally known synthetic resin binders for resin concrete such as unsaturated polyester resins and epoxy resins can be used, but hydrophilic resin binders described later can also be used.

If a hydrophilic resin binder or surfactant is used in conjunction with the use of a hydraulic material, the influence of the difference in specific gravity between the foamed particles of the hydraulic material and the foamed particles can be more effectively suppressed. These resins (ingu are synthetic resin emulsilane,
For example, vinyl acetate polymers such as vinyl acetate polymers, ethylene-vinyl acetate copolymers, acrylic ester-vinyl acetate copolymers, maleic ester-vinyl acetate copolymers, acrylic ester polymers, styrene-based polymers, etc. Acrylic polymers such as acrylic acid ester copolymers, vinyl chloride polymers and their copolymers, vinyl chloride polymers, S
BR polymers, ethylene-(meth)acrylic acid or its ester copolymers, or metal salts thereof, etc., especially low molecular weight ethylene-carboxylic (acrylic)
Examples include acid copolymers, ethylene-carboxylic (acrylic) acid-carboxylic (acrylic) acid ester copolymers, or metal salts and amine salts thereof.

As the surfactant, any of nonionic, anionic, cationic, and amphoteric types may be used.

In the present invention, aggregates include not only sand, gravel, crushed stone, slag material, artificial nil aggregate, etc., but also waste materials such as high-quality soil and excavated soil, and the purpose of use of the pavement structure to be constructed. Select and use the appropriate one according to the situation.

In the present invention, the foamed particles are not particularly limited; for example, foamed particles made of synthetic resins such as polystyrene resins, polyolefin resins such as polyethylene and polypropylene, polyurethane resins, polyvinyl chloride resins, and epoxy resins; Pearlite, shirasu balloons, glass balloons, metal balloons, etc. (including hollow bodies, etc.), but among them polyolefin resins, especially closed cells with a bulk density of 0.1 g/c+a' or less and a compression set of 30% or less The foamed polyolefin resin particles made of polyolefin resin are not only inexpensive but also preferable in terms of water resistance, compression resistance, light weight, etc.

The above polyolefin resins include low, medium, and high density polyethylene, polypropylene, polybutene-1, poly-
Homopolymers such as 4-methylpentene-1, α-olefin interpolymers such as ethylene, propylene, butene-1,4-methylpentene-1, hexene-1, and octene-1, ethylene and vinyl acetate copolymers Copolymers of ethylene and (meth)acrylic acid or its esters, or copolymers obtained by grafting acrylic acid, unsaturated carboxylic acids such as maleic anhydride, or styrene onto these polyolefin resins, and mixtures thereof. It is.

A blend of the above polyolefin and polystyrene can also be used as a raw material for foamed particles.

Among these, ethylene-propylene random copolymers, ethylene-propylene block copolymers, and propylene-ethylene block copolymers are particularly preferred.

Furthermore, the foamed particles of the present invention include not only foamed beads formed by foaming beads, but also crushed foams such as new or recycled foam boards and foam blocks.

The foamed particles preferably have a bulk density of 0.1 g/cd or less, a thermal conductivity of 0.05 Keal/rm, and hr°C or less.

In the present invention, it is preferable to use the polyolefin resin expanded particles, but the polyolefin vAII! 9. If the bulk density of the expanded particles exceeds 0.1 g/c, there is a possibility that the insulation and lightness will be lost, and if the compression set exceeds 30%, the It has low shape recovery properties and may cause ruts or unevenness on roads, etc., and if closed cells are not formed, water may penetrate and the insulation may be lost.

The essential components constituting the pavement structure of the present invention are as described above, but within the scope of the gist of the present invention, thermoplastic resins, petroleum resins, curable resins, rubber, curing agents, curing accelerators, etc. A curing retarder, an AE agent, a water reducing agent, a dispersant, a foaming agent, a rust preventive, an inorganic filler, a pigment, etc. may be appropriately selected and used. It is particularly effective to use civil engineering fibers in combination.

The civil engineering fibers referred to here are not particularly limited to short fibers made of resin, small pieces of non-woven fabrics, small pieces of textiles, etc. When mixing in a pot, mix easily by spraying a predetermined amount in advance.

In the first invention, the mixture for cutting such as conversion has expanded particles, a binder, and aggregate as essential components, and the liquid content ratio is essentially equal to or lower than the flow pressure.

The above liquid content ratio refers to the liquid content contained in the mixture, the water contained in the aggregate, the water content in the binder, the liquid content and added water, etc., which give the mixture fluidity. What is desirable is that when compacting the foam mixture, it should be spread evenly at the moisture content ratio that makes it most compact (optimal water content ratio), and through a compaction process, the desired pavement structure can be constructed. It is. At this time, of course, if the water content of the mixture itself is less than the optimum water content, it is necessary to adjust it by sprinkling water or the like during spreading and rolling.

This mixture may be prepared separately at the plant or on-site. By combining the use of foamed particles and the condition of a liquid content ratio below fluidization, the difficulty in construction and the tendency for layer separation due to the difference in specific gravity between the foamed particles and other materials can be significantly suppressed, thereby achieving the above-mentioned object of the present invention. This can be accomplished easily and inexpensively.

Examples of construction processes using the plant U combination method include mountain sand,
Aggregate and foamed particles made of gravel, crushed stone, etc. are mixed together with cement or asphalt emulsion in a plant,
The mixture is transported to the construction site, spread on the surface to be paved such as the foundation or roadbed, and compacted to form a heat insulating layer. Next, if desired, asphalt emulsion is sprinkled to form a curing film. There are examples where a surface layer of asphalt concrete or the like is provided on top of it.

The second invention and subsequent inventions are also effective as one of the methods of implementing the first invention, but are not necessarily limited thereto.

Both methods correspond to the on-site mixing method, in which foam particles are usually first placed on the surface to be paved.

In the second invention (FIG. 3), the foamed particles are spread over one surface, and then aggregate and binder are kneaded and paved by conversion or the like.

In the third invention, after a resin bag filled with a certain amount of foam ladles is laid down, the resin bag is torn, and at the same time, a binder and aggregate and/or native soil are kneaded and paved by conversion or the like. Resin bags are usually incorporated into pavement in a torn state. Note that if it is desired to avoid incorporating torn resin bags into the pavement, water-soluble resin bags may be used.

In the fourth aspect of the invention, after a certain volume of foamed particles is spread in blocks formed by temporarily adhering them in advance, each block is broken while being kneaded with aggregate and a binder, and paving such as conversion is carried out.

In these cases, on-site mixing should be done efficiently using construction machinery such as road stabilizers.

Fig. 3 shows the construction procedure of the second invention, - as an example,
In Figure 1, after leveling the foam particles on the subgrade (1) which has been lowered to a depth of approximately 30 cm from the road surface, aggregate consisting of mountain sand, crushed stones, etc. Sprinkle cement on top of the spread, and use a load stabilizer to mix the foamed particles, aggregate, and cement well while adjusting the moisture content.
A heat insulating layer (6) made of the foamed particle mixture is formed by rolling with a road roller or the like. Next, if desired, an asphalt emulsion is spread to form a curing film, a top layer of ordinary aggregate is applied, and a surface layer of asphalt concrete or the like is provided on top of that.

In the second invention, since the foam particles themselves are spread alone, stable construction may be difficult as they may be scattered under the influence of the wind, or the foam particles]! ! ! There are some problems, such as the time it takes to transport and measure during compounding.

On the other hand, an open fat bag filled with foamed particles as in the third invention or a block-shaped bag made of foamed particles temporarily bonded with heat or adhesive as in the fourth invention are laid, and these bags are torn. Alternatively, by mixing cement, aggregate, etc. while crushing, the method of the second invention has the effect of speeding up and stabilizing the M-level of foamed particles, the measurement at the time of mixing, and the construction.

It should be noted that reinforcing materials (synthetic resin sheets, synthetic T!L fat nets, gold 4, reinforcing bars, etc.), heat insulating materials (foam sheets, Provide at least one layer consisting of foam boards, foam blocks, foam concrete, rubber chips, perlite, foam shells, hollow bodies such as glass balloons, etc.), water drainage materials (rubber sheets, water-containing fluids (grease, etc.)) is also preferable.

It is also possible to make the above heat insulating layer multi-layered by using foamed particles with the same density or different densities.

As understood from the above description, the present invention includes the embodiments described in F.

(1) The heat-insulating pavement structure according to any one of claims (1) to (4), wherein a multilayer heat-insulating layer is formed by using foamed particles having the same density or different densities on the surface to be paved. construction method.

(2) At least one layer selected from the group consisting of a reinforcing material, a heat insulating material, and a water stop H is applied to the heat insulating layer from any one of claims (1) to (4), in the order of Q. How to construct a heat-insulating δ11 structure, which is characterized by its construction.

(3) The method for constructing a heat-insulating pavement structure according to any one of claims (1) to (4), wherein the foamed particles are particle size-adjusted.

(4) The foamed particles are made of a polyolefin-based 18 resin foam ladle consisting of closed cells with a density of 0.1 g/cur or less and a pressure P6 permanent work of 30% or less. 11. The method of constructing a heat insulating pavement structure according to claims 11 to 4.

(Operations and Effects of the Invention) The present invention solves the problem of foam particles separating during continuous transport when mixing in a plant and transporting to a site because the mixture itself has no fluidity. It is possible to eliminate complicated work processes associated with material separation.

When mixed in a commercial field, a layer of foamed particles can be easily applied.Furthermore, the foamed particle mixture of the present invention has a high load-bearing capacity, so it is suitable for use on pavements such as jω #5 discs and/or It can be used as an upper layer roadbed, etc., and can further enhance the heat insulation effect.

Therefore, roads, playgrounds, tennis courts, etc. in cold regions can be constructed economically.

In addition, since the pavement structure of the present invention can be constructed easily and at low cost, it can function as a conventional frost heaving prevention layer, as well as a support layer for the purpose of reducing consolidation settlement of soft ground. It has thermal insulation properties and can be used as a paving structure. In addition, since there are no restrictions on the construction of bones, it becomes possible to use locally generated soil or to reuse excavated soil, which also solves the problem of disposing of surplus soil, which is a social requirement.

When used as a pavement structure using an asphalt-based or resin-based binder as the surface layer of a promenade, etc., it can also be used as a resilient pavement.

End of civil engineering! ! In the case of contamination, there is also the effect of improving the cracking effect of these layers in which foamed resin particles are mixed.

(Example) The present invention will be explained in more detail with reference to Examples below.

A pavement with a structural cross section as shown in Figure 4 [1], fbl, tel was constructed.

(el is a standard structure using the conventional construction method, (11) is a structure using the foamed particle mixture according to the present invention in the upper base course, (b)
1 is the structure similarly used for the upper roadbed. fan,
The foamed particle mixture layer of FBL is not only effective as a heat insulating layer, but also plays the role of a load-bearing layer for pavement.
The blending ratio of expanded particles was determined so that the 08 scale of each mixture was 80 or more and 20 or more (Table 1).

The temperature of each pavement structure was maintained at -30°C, and the temperature (at the boundaries of each pavement layer) and freezing depth were measured.

FIG. 5 (a, l, (b), tc+ indicates the depth at which the temperature reaches 0° C. and the separately measured freezing depth in each structural cross section.

From these figures, it can be seen that the pavement structure in which the foamed particle mixture with high bearing capacity characteristics according to the present invention is placed near the pavement surface has a reduced heat insulation effect, and furthermore, the pavement structure can be made thinner.
Can provide economical new and old.

Table 2 The foamed particles include "8 stone polypro 350Jj (Ml.
-8) Average particle size obtained by foaming polypropylene: 5
"P-Block" with density 0,025 g/ci
(Japan Styrene Paper<myi) was used.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the road pavement structure of the present invention, FIG. 2 is a sectional view of a conventional road pavement structure, and FIG.
It is a schematic diagram showing the construction process in the Xi combination method. Fig. 4 (ft++, +bl) shows the cross-sectional structure of the public body of the example, and Fig. 4 (C) (well, the conventional construction method shows the floating parrot structure. Fig. 5 shows each example and the comparison Examples of freezing depth and measured temperature are shown. (1) ... Roadbed (2) Frost heave suppression layer (3)
...lower roadbed (4) Upper P! MPJ board (5
)...Surface layer (6) - Foamed particle mixed layer. Patent applicant: Hiki Hodo Co., Ltd. Japan Styrene Paper Co., Ltd. Japan Petrochemical Co., Ltd.

Claims (4)

[Claims] (1) A method for constructing a heat-insulating pavement structure, which comprises paving a layer of a mixture containing foamed particles, a binder, and aggregate as essential components and having a liquid content ratio below fluidization on a surface to be paved. (2) A method for constructing a heat insulating pavement structure, which comprises spreading foam particles all over the surface to be paved, and kneading the foam particles with at least a separately supplied binder, aggregate and/or native soil. (3) A resin bag filled with a certain amount of expanded particles is spread on the surface to be paved, and at least a binder and aggregate, which are separately supplied, are kneaded and paved at the same time as the resin bag is broken. Construction method of insulated pavement structure. (4) On the surface to be paved, blocks made of foamed particles preliminarily attached to a certain volume are spread, and at least a separately supplied binder and aggregate are kneaded while breaking the blocks, and paving is carried out. Features: Construction method of heat-insulating pavement structure.