JP4699711B2 - Pavement structure and pavement method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a pavement that can be suitably used in mountain forests, walkways in forests, parks, open spaces, grounds, and the like, and more particularly, to a pavement using a woody material obtained by pulverizing a heartwood or bark of a tree as one of materials. It is.

  In recent years, a so-called wood pavement in which materials including a heartwood of a tree or a crushed bark are stacked is sometimes used in a forest, a promenade in a forest, a park, a plaza, a ground, and the like. Wooden pavement has better cushioning than ordinary asphalt pavement and concrete pavement, so it has good walking feeling for pedestrians or runners, reduces the impact on the knees, and is highly safe when falling. It has become a thing. In addition, since natural wood is used, it has a natural color and is in harmony with the surrounding landscape.

  On the other hand, conifers such as cedars and cypresses, such as trunks, branches, and bark, are produced in large quantities in various parts of Japan, but these are difficult to reuse and most of them are incinerated. Such a waste material can be used effectively in the wooden pavement, and the cost of the material becomes low.

  In the above-mentioned wooden pavement, if a wooden material is simply laid on the surface, it will be excessively soft until the wooden material is stepped after construction, and the walking feeling or running feeling will be poor. In addition, the wood material on the surface may be blown away by wind and rain or may flow out to the surroundings.

For this reason, a pavement has been proposed in which a binder such as a moisture-curing urethane polymer, an epoxy resin, or a polyester resin is added to a wood material and kneaded, and the kneaded material is laid as a surface layer (Patent Document 1 and Patent Document). 2). In this pavement, the surface layer has appropriate elasticity, and a good walking feeling or running feeling can be obtained, and the bark or heartwood pulverized by using a binder is combined and hardly scattered.
JP 2001-336103 A JP 2001-131903 A

  However, in the wooden pavement described in Patent Document 1 and Patent Document 2, the material cost is increased by using the binder, and the work man-hour is increased because the wooden material and the binder are kneaded using a mixer or the like. And it costs a lot. In addition, when sand, aggregate, or the like is mixed, the specific gravity of each material is different, so unevenness tends to occur when these are kneaded, and the mixers that can be used are limited. Further, after kneading the binder, the laying operation must be performed quickly before the fluidity of the material is impaired, and there is a problem in workability. Moreover, after laying the material, the construction site cannot be opened until the binder is completely cured, and cannot be used immediately after construction. Furthermore, since this wooden pavement uses a binder that is not a natural substance, it is not desirable to construct it in a natural environment such as a forest or forest.

  The invention according to the present application has been made in view of the circumstances as described above, and the purpose thereof is to use a woody material made of a heartwood or bark of a tree, and has good walking and running characteristics, and the environment. It is to provide a pavement structure and a pavement method which are harmonized and excellent in workability and economy.

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that the grain size distribution is adjusted on the ground or roadbed, the wood material made of crushed bark or crushed tree heartwood. A mixture layer of sand and clay is laid, and the mixture layer spreads the wooden material, sprays the sand and the clay that has been dried into powder, and stirs these And a pavement structure that is rolled after mixing .

  The pavement made of the above mixture is a layer in which the wood materials are entangled with each other and are soft and elastic and resilient to deformation. And although the wood material alone is too soft and the walking sensation is deteriorated, the sand enters the gaps between the wood materials and the hardness is adjusted by mixing the sand. Therefore, by appropriately adjusting the amount of sand, it is possible to easily obtain a pavement having a hardness that does not give a large impact to a pedestrian's knee or the like and is suitable for walking and running. Moreover, in the mixture of a wooden material and sand, a wooden material piece peels off from the surface by a person's walking or running, and is easily dissipated to become a rough surface. This tendency becomes remarkable especially in the dry state. On the other hand, in the pavement structure of the above invention, since clay is mixed, the clay retains moisture, and the viscosity increases the adhesion between the wood materials and between the wood materials and the sand. For this reason, there is little scattering of wooden material and sand from the surface, and the surface state becomes stable. In addition, even if the drying is advanced, the clay is filled and entangled with the wood material, and thus has an effect of preventing the surface from becoming rough.

  Furthermore, this pavement structure is inexpensive, and does not require expensive materials such as synthetic resin as a binder, can reduce the work period and cost, and does not use a hardened binder. As an excellent feature, it can be used immediately after repair, and it is easy to work even during repairs, and because it consists of only natural objects, it is environmentally friendly and the color tone harmonizes with nature. Can do.

The invention according to claim 2 is the pavement structure according to claim 1, wherein the clay has a so-called swelling property in which particles adsorb 3 to 20 times the weight of water and expand .

  By using a clay that adsorbs a lot of water, a large amount of water can be retained in the pavement, and the woody material is kept in a flexible state. For this reason, scattering of the woody material and sand can be reduced, and the pavement has moderate flexibility.

  Some clay minerals are known to expand by adsorbing a large amount of water. For example, by having a layered crystal structure, water is adsorbed between the layers to expand. By mixing such clay with the wood material, it enters between the wood materials and expands and adheres to increase the adhesion between the wood materials. Therefore, it is possible to effectively suppress the wooden material pieces from being separated and dissipated. In addition, since a large amount of water is retained, the function of supplying moisture to the woody material and maintaining a flexible state is great.

For example, bentonite is a clay mainly composed of extremely fine amorphous plate-shaped montmorillonite, and adsorbs a lot of water and exhibits swelling properties. Bentonite is used for various purposes, and is a cheap and easily available material. Therefore, it is a material suitable for forming the pavement structure according to the present invention, and has an excellent performance for maintaining the wooden material in a stable state, and the construction cost can be kept low.

The invention according to claim 3 is characterized in that a wooden material made of crushed bark or crushed tree heart is spread on the roadbed, and further, sand having a adjusted particle size distribution and dried and powdered. The present invention provides a pavement method in which, after sprinkling with the clay, the mixture is stirred and mixed, and the mixed layer is sprinkled with water.

  This paving method is to stir and mix wood material, sand and powdered clay in the area to be paved, and eliminates the need for a mixer, etc. Can be reduced. Further, at this time, the clay is in a dry state and can be easily stirred and mixed by using it as a powder, and can be uniformly mixed with the wood material and sand. Then, by spraying water after stirring and mixing, the clay and the woody material absorb water and can be compacted efficiently. Moreover, the pavement has moderate flexibility and surface stability immediately after the completion of construction, and the construction site can be opened immediately after the construction. Furthermore, the work becomes easy during repair.

  Moreover, in this pavement method, the sand can be mixed into the wood material, and the surface can be adjusted to a hardness suitable for walking or running by adjusting the amount thereof, and further, a binder such as a synthetic resin can be added by mixing clay. Even if it is not used, peeling and scattering of the wooden material can be effectively suppressed.

The invention according to claim 4 is the paving method according to claim 3, wherein the step of spraying potassium chloride on the surface of the compacted layer, or the pipe is penetrated into the compacted layer and the potassium chloride is press-fitted. It includes a process.

  By adding potassium chloride to the pavement, water retention is improved and the woody material and clay are maintained in a moderately flexible state.

In the invention according to claim 5, a mixture layer of a wood material made of crushed bark or crushed tree heartwood and sand having an adjusted particle size distribution is laid on the roadbed, and the mixture layer is made of the wood The present invention provides a pavement structure in which the above-mentioned sand is laminated on a material spread and mixed, stirred and mixed, and then rolled.

The sand is mixed with the wood material, so that the mixture layer has an appropriate hardness and strength, and has a good feeling of walking or running for the user. Moreover, since the mixture layer is made of a wood material and sand without using a binder such as a synthetic resin, an appropriate gap can be formed between the wood materials. Thereby, water retention and water permeability become good, and the pavement is maintained in a moderately flexible state.
On the other hand, since this mixture layer is made by laminating, mixing and mixing wood materials, stirring and mixing, it is easy to construct and does not require an installation mixer, reducing the construction period and cost. be able to. In addition, the work is facilitated during repair.

The invention according to claim 6 is the pavement structure according to claim 5 , wherein the mixture layer is obtained by mixing organic soil with the wood material in addition to the sand or in place of a part of the sand. To do.

  The organic soil is a soil that forms a surface layer of, for example, a forest, a mountain forest, or a grassland, and contains a large amount of corrosive substances such as bark, tree branches and leaves, and organic substances such as wood-rotting fungi and bacteria. Therefore, if the construction site is in a forest or park, the soil collected at the site can be used. This organic soil can be used in combination with a wood material in advance, or can be used after being spread and mixed with sand after the wood material has been laid. When such an organic soil is mixed in the mixture layer, water retention is improved, the wood material is prevented from becoming hard and the surface is roughened, and can be maintained in a stable state. Further, the corrosion of the wood material is promoted by microorganisms contained in the organic soil, and the wood material is compacted appropriately, so that the surface becomes a hardness suitable for walking in a short period after construction.

According to a seventh aspect of the present invention, in the pavement structure according to the fifth aspect, the mixture layer includes a wood material having undergone corrosion.

  In the above configuration, the wood material that has been corroded is a wood material that has been naturally corroded or a wood material to which corrosion has been accelerated by adding a corrosion accelerator in advance. By mixing such a wood material in the mixture layer, the water retention is improved, and the wood material is rapidly corroded and hardened by wood decaying bacteria or bacteria contained in the wood material.

  As described above, in the pavement structure according to the present invention, it is possible to easily finish the layer containing the wood material made of the pulverized material of the heart of the tree or the bark to a hardness suitable for human walking or running. Become. Moreover, construction is easy and a construction period and cost can be reduced. Furthermore, since this pavement structure does not use a binder that hardens after construction, it can be used immediately after construction, and the work becomes easy even during repair. In addition, because it is composed only of natural objects, it is environmentally friendly and the color tone is in harmony with nature.

  On the other hand, in the pavement method according to the present invention, the mixture layer containing the wood material composed of the heartwood or bark of the tree is mixed after each material is spread and mixed in the area to be paved, so that the construction is simple. In addition, an installation type mixer is unnecessary, and the construction period and cost can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a pavement that is an embodiment of the present invention.
This pavement is used for mountain forests and forest trails, etc., with the ground flattened and compacted, and then wood material consisting of crushed bark or heartwood, and sand whose particle size distribution is adjusted A mixture layer 2 containing clay is laid.

  The wood material used in the mixture layer 2 may be, for example, a material obtained by pulverizing conifer bark to a length of about 1 mm to 200 mm and a width of about 1 to 20 mm. The bark of coniferous trees is preferably used because the shape of the pulverized product is elongated and easily entangled with each other, and is difficult to be scattered by wind and rain after construction. Moreover, since it becomes a structure where pulverized products are entangled with each other, the mixture layer 2 is excellent in water retention and water permeability.

Further, fine sand having a maximum particle size of 2.5 mm or less and having a passage of 0.6 mm sieve of 70% or more can be preferably used. The water content ratio during mixing is preferably about 10% from the viewpoint of workability.
In addition to the above, sand can be used by changing the particle size distribution and the like depending on the quality and type of the wood material, the use of the road to be paved, and the like.

  The clay desirably adsorbs water and swells, and bentonite can be preferably used. Also, clay having a small swelling property can be used, but a clay having a dry weight of 2 g showing a swelling volume of 20 ml or more in water is most suitable, and a clay showing a swelling volume of 10 ml or more can also be suitably used.

The mixing ratio of the pulverized wood material, sand, and clay can be set as follows, for example.
Bark crushed material: 9.2 kg / m ² (75 liters / m ² )
Fine sand: 43.1 kg / m ² (25 liter / m ² )
Bentonite: 2.6 kg / m ²
However, the above formulation is based on the premise that a pavement having a thickness of about 40 mm is formed, and the fine sand is shown as the dry weight, and the bentonite is shown as the dry weight.
Note that the bark pulverized product is a natural product, and the same material is not always available depending on the tree species, the collection site, and the like. Therefore, in the construction, it is desirable to appropriately increase or decrease the blending weight of the fine sand and the blending weight of bentonite according to the material to be used. The mixing ratio of fine sand and bentonite to crushed bark is 9.2 kg / m ² (75 liters / m ² ) of fine crushed bark, and is 17.2 to 86.2 kg / m ² (10 to 40 liters / m ² ). m ^2), it is desirable to bentonite 0.1 to 10 / m ^2, fine sand 34.5~51.7kg / m ² relative to bark pulverized product 9.2kg / m ² (75 liters / m ²⁾ (20-30 liters / m ² ) and bentonite of 1-3 kg / m ² are most suitable.

Next, the construction method of the said mixture layer 2 is demonstrated based on FIG.
First, level the area to be paved, flatten and then roll. Then, the prepared wooden material, sand and bentonite are carried to the site and spread on the ground prepared in the order of the wooden material, sand and bentonite. The leveling is performed using a machine such as human power or a finisher. Next, the tilled material is stirred and mixed using a tiller as shown in FIG. At this time, the stirring member 3 of the tiller reaches the pressed ground and takes up some amount of the compacted soil into the mixture layer, or the wooden material and the rolling pressure that the stirring member 3 spreads. There may be a range that does not reach the boundary surface with the ground and is not sufficiently mixed in the lowest layer of the spread material, but even if such a situation occurs, the performance of the pavement is hardly affected.

When stirring / mixing is completed as described above, water is sprinkled, and rolling is performed by a vibrating roller of about 0.5 to 1.0 t to finish flat and roll to an appropriate hardness. The amount of water to be sprayed is preferably about 5 liters / m ^2, but can be increased or decreased as appropriate.
After completion of the rolling, an aqueous solution of potassium chloride may be sprayed. Further, an aqueous solution of potassium chloride may be press-fitted by penetrating a thin tube into the rolled mixture layer. Thus, water retention can be improved by adding potassium chloride.

  In the construction method as described above, it is not necessary to mix the wood material and the synthetic resin binder, and an installation type mixer is also unnecessary. For this reason, construction is simple and the construction period and cost can be greatly reduced. Moreover, it can be set as the hardness which is easy to walk or drive | work by mixing sand to a wooden material and adjusting this quantity. Moreover, the construction site can be opened immediately after the construction, and the work becomes easy even during repairs. Furthermore, since it is composed only of natural materials, it can be suitably used in a natural environment.

The following measured values are obtained for the characteristics of the mixture layer as pavement, that is, impact absorbability (GB coefficient), elastic resilience (SB coefficient), and Proctor needle penetration resistance test.
Here, the GB coefficient indicating the shock absorption is a bound height when the golf ball is naturally dropped from a height of 100 cm at 20 ° C. Further, the SB coefficient indicating elastic resilience is the bounce height when a steel ball having a diameter of 1 inch is naturally dropped from a height of 100 cm at 20 ° C. The GB coefficient and the SB coefficient are measured in accordance with the description in “Pavement Test Method Handbook” (edited by the Japan Road Association, published by Maruzen Co., Ltd., December 2002).
The Procter Needle Penetration Resistance Test conforms to the description of “Guidelines for Outdoor Sports Facility Construction” (Japan Sports Facility Association, 1999 edition).

  The above-mentioned impact absorbability (GB coefficient) is about 3%, and the elastic resilience (SB coefficient) is about 5%, which is slightly softer than normal clay pavement. Further, the Procter needle penetration resistance test shows about 20 pounds, which is a soft value as compared with a normal baseball field. From these measured values, it can be seen that the pavement has a hardness in a range suitable for walking or running, and the burden on the knee is small.

Next, a pavement structure which is an embodiment of the invention according to claim 5, claim 6 or claim 7 will be described.
In this pavement structure, the mixture is formed by mixing a wooden material and sand, and clay such as bentonite is not used. The same wood material and sand as the pavement structure shown in FIG. 1 are used, and the mixing ratio of the wood material, that is, the bark pulverized material is 9.2 kg / m ² (75 liters / m ² ), The fine sand is 43.1 kg / m ² (25 liters / m ² ). Similarly, the construction method can also be carried out in the same manner by placing a wooden material and sand on the ground after leveling, stirring and mixing with a tiller.

  Since this pavement structure does not contain clay, if there are many pedestrians, the surface may become rough and some bark may peel off or dissipate, but it has the same flexibility as the pavement structure shown in FIG. It is possible to easily form a pavement. Moreover, although the surface is likely to be rough as described above at the beginning of construction, the surface becomes settled and stable when the wooden material begins to corrode gradually.

  Further, in this pavement structure, a part of the fine sand can be replaced with so-called organic soil that is a soil that forms a surface layer of a forest, a forest, etc. and contains a large amount of organic matter. Moreover, organic soil can also be added to the fine sand. In the forest or mountain forest where the pavement structure is constructed, the organic soil as described above can be easily obtained at the construction site and can be constructed at low cost. Moreover, water absorption improves by mixing organic soil, and the compaction efficiency at the time of rolling is improved. For this reason, the hardness of the pressed pavement is slightly harder than when organic soil is not mixed, but it can have a pavement structure with moderate flexibility and good surface stability.

  Furthermore, the organic soil contains wood decay fungi, bacteria, and the like, and promotes corrosion of wood materials such as bark. Thereby, the mixture layer laid as pavement is properly compacted and becomes a stable state at an early stage, and the scattering of the wooden material can be reduced.

  Moreover, it can replace with the wood material used by the said mixture layer 2, or it mixes with the said wood material, and can also use the wood material which corrosion progressed naturally, or the material which the corrosion promoter was added previously and corrosion was accelerated | stimulated. . For example, those obtained by pulverizing a heartwood or bark of a tree and then proceeding corrosion in a deposited state can be used. By using such a material, it becomes easy to compact the mixture layer to an appropriate hardness, and the corrosion of the wood material used is promoted, and the surface can be stabilized in a short period after construction. it can.

  In addition, the pavement structure described above is prepared by leveling and rolling the ground in the area to be paved and spreading a mixture layer, but forming a roadbed on the ground, laying the mixture layer on this Also good. The roadbed may be formed by rolling a crushed stone having an adjusted particle size distribution, or a crusher run may be spread and compacted. For example, a crusher run having a particle size standard of C-40 (upper limit of particle size: 40 mm) is spread over a thickness of about 10 cm to 15 cm, and rolled using a vibration roller of about 0.5 t to 1.0 t. Can do. The crusher orchid is a crushed stone that is obtained by simply dividing a rock or cobblestone with a crusher and not sieving it.

It is a schematic sectional drawing which shows the pavement structure which is one Embodiment of this invention. It is a flowchart which shows the outline of the construction method of the pavement structure shown in FIG. It is the schematic which shows the state which stirs and mixes the mixture layer laid on the ground.

1: ground, 2: mixture layer, 3: stirring member

Claims (7)

On the ground or roadbed that has been leveled , a mixture of wood material made of crushed bark or crushed tree heart, sand with adjusted particle size distribution, and clay is laid.
The mixture layer is obtained by spreading the wooden material, spraying the sand and the clay that has been dried and powdered thereon, stirring and mixing them, and then rolling the mixture. A characteristic pavement structure. 2. The pavement structure according to claim 1, wherein the clay has a so-called swelling property in which particles adsorb 3 to 20 times by weight of water and expand . On the roadbed, lay a wooden material consisting of crushed bark or crushed tree heartwood,
On top of that, after spraying the sand whose particle size distribution was adjusted and the clay which was dried and powdered, these were stirred and mixed,
A pavement method characterized by sprinkling and rolling the mixed layers. 4. The pavement method according to claim 3, comprising a step of spraying potassium chloride on the surface of the pressed layer, or a step of penetrating a tube into the pressed layer and pressing potassium chloride. On the roadbed, a layer of a mixture of a wood material made of crushed bark or crushed tree heartwood and sand with a controlled particle size distribution is laid,
The mixture layer is a pavement structure in which the wood material is spread and leveled, the sand is laminated, and after stirring and mixing, the mixture is rolled. The pavement structure according to claim 5, wherein the mixture layer is a mixture of organic soil and the wood material in addition to the sand or in place of a part of the sand. The pavement structure according to claim 5, wherein the mixture layer includes a wood material that has undergone corrosion.

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