JP2003277164A - Porous structural body and construction method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily perform quality control and to excellently maintain strength even in site work in a porous structural body for buildings or structures and to provide a method for constructing the porous structural body. <P>SOLUTION: The porous structural body has pores which are formed by shrinking or eliminating a water soluble, heat soluble, biodegradable or alkali decomposable pore forming material incorporated into a base material such as concrete constituting the structural body by water dissolution, heat dissolution, biodegradation or alkali decomposition. As the construction method, the base material such as concrete constituting the porous structural body and the water soluble, heat soluble, biodegradable or alkali decomposable pore forming material are kneaded and hardened and at the same time. In this process, the water soluble, heat soluble, biodegradable or alkali decomposable pore forming material is water-dissolved, heat-dissolved, biodegraded or alkali- decomposed to be shrunk or eliminated to form the pores in the structural body. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for construction, construction, etc., and more particularly to a porous structure having voids inside for imparting water permeability, heat insulation and the like, and a method for constructing the structure.

[0002]

2. Description of the Related Art Conventionally, when a porous structure for construction or construction, which is made of concrete, mortar, plaster, etc., is required to have water permeability or heat insulation, for example, the inside of the structure such as porous concrete is used. The one having a void is used. This porous concrete, for example, by forming a void inside by reducing the mixture ratio of cement to the aggregate such as poor mixture, that is, sand or gravel,
Alternatively, a void is formed inside by means of foaming, foaming, air entrainment, or the like.

However, when the above-mentioned poor composition is used, it is unavoidable that a portion where the solidified cement paste C is not adhered to the aggregate B as shown in FIG. 19 and the strength is significantly reduced. Also, the state of the voids A changes depending on the material mixing, mixing method, temperature, etc., so there are relatively few problems when forming into blocks in factory production, etc. There was the inconvenience of being very difficult.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above problems, and quality control is easy not only in factory production but also in on-site construction, and the required strength can be satisfactorily obtained. An object of the present invention is to provide a porous structure and a construction method thereof.

[0005]

In order to achieve the above object, the porous structure according to the present invention has a water-soluble property, a heat-soluble property or a biodegradable property which is mixed in a base material such as concrete constituting the structure. Characterized in that it has a void in the structure formed by shrinking or disappearing a void-forming material having a water-soluble or alkali-decomposable property by water dissolution, heat dissolution, biodegradation or alkali decomposition.

Further, the method for constructing a porous structure according to the present invention comprises a base material such as concrete which constitutes the porous structure,
While kneading and curing with a void forming material having water solubility, heat solubility or biodegradability or alkali decomposability,
The void-forming material is characterized in that the voids are formed in the structure by shrinking or disappearing by water dissolution, heat dissolution, biodegradation or alkali decomposition.

Further, another method of applying the porous structure according to the present invention is to dispose a void-forming material having water solubility, heat solubility, biodegradability or alkali decomposability at the position where the porous structure is applied. , Placing or spraying a base material such as uncured concrete that constitutes the structure so as to cover the void forming material, and while curing the base material,
The void-forming material is characterized in that the voids are formed in the structure by shrinking or disappearing by water dissolution, heat dissolution, biodegradation or alkali decomposition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The porous structure and the method for constructing the same according to the present invention will be specifically described below based on the embodiments shown in the drawings.

FIG. 1 shows that the porous structure according to the present invention is applied to the wall surface W of the tunnel, instead of the shotcrete which is applied as a so-called primary lining. In the figure, reference numeral 1 is a porous structure according to the present invention, and a water-soluble, heat-soluble, biodegradable or alkali-decomposable void-forming material mixed in a substrate such as concrete is provided in the structure 1. A large number of voids formed by shrinking or disappearing by water dissolution, heat dissolution, biodegradation or alkali decomposition are provided. In the figure, 2 is a waterproof material formed of a waterproof sheet made of rubber or the like or waterproof concrete, 3 is secondary lining concrete, and G is a natural ground.

In constructing the above structure 1,
Kneading by adding an appropriate amount of water-soluble, heat-soluble, biodegradable or alkali-decomposable void-forming material to a base material such as concrete in which an appropriate amount of cement and water are mixed with aggregates such as sand and gravel In addition to concrete, mortar, gypsum, asphalt, etc. can be used as the base material.

As the above-mentioned void forming material, for example, a water-soluble or heat-soluble material made of collagen such as gelatin or glue, a biodegradable material typified by polylactic acid fiber,
Alternatively, it is possible to use an alkali-decomposable material such as glass fiber having a property of being eluted by being invaded by alkali, and the properties of the void forming material are granular, fibrous, string-like, rope-like, capsule-like, mesh-like, etc. Others are appropriate. By appropriately selecting the shape of the void-forming material according to the required properties of voids, voids of any shape can be formed in the porous structure.

It should be noted that the powdery void-forming material may be used by molding it into a granular shape, a fibrous shape, a string shape or the like. For example, in the case of powdery gelatin 10 or the like, it may be used as shown in FIG.
After being poured into the hot water b in the stirring container S and stirred and mixed, it is put into a molding die F having a predetermined shape as shown in FIG. Next, when it is solidified into a jelly, it is cut into rods as shown in FIG. 7C, and if it is cooled and dried in a refrigerator or the like not shown in the figure, the fibrous void forming material 11 as shown in FIG. can get.

The above-mentioned base material and void-forming material are put into a mixer M or the like as shown in FIG.
A hopper H or the like sequentially supplies pressure to a construction position by a pump P or the like to drive or blow it onto a tunnel pit wall surface W to form a structure 1, and then the water blocking material 2 and a secondary lining concrete 3 are formed on the surface thereof. And are to be constructed.

A void-forming material is mixed in the structure 1 formed as described above, and the void-forming material is water-dissolved, heat-dissolved, biodegraded or alkali-decomposed. For example, when concrete, mortar, gypsum, or the like is used as the base material and a water-soluble or heat-soluble material made of collagen such as gelatin or glue is used as the void-forming material, water and tunnel in the base material are used. The void-forming material can be decomposed by water that permeates into the structure from the wall surface and heat by the hydration reaction of cement or the like in concrete.

When a biodegradable void-forming material is used, it can be decomposed by microorganisms or the like that enter from the inside of the structure 1 or its peripheral portion, and an alkaline-degradable void-forming material is used. When used, it can be decomposed by the alkaline component contained in the base material such as concrete, mortar or gypsum.

Furthermore, when polylactic acid fiber obtained from lactic acid obtained from starch such as corn is used as the void-forming material, it can be decomposed by microorganisms and also due to the alkaline component contained in the base material. Can be disassembled.

By decomposing the void-forming material in the structure 1 in this manner, voids are formed at the places where the void-forming material contracts or disappears. For example, the void-forming material in the form of particles or capsules. If you use
When a large number of bubble-like voids A are formed independently of each other as shown in (a) and a fibrous or rope-like void forming material is used, the voids are as shown in (b) of the same figure. A is formed in a substantially linear shape and adjacent portions communicate with each other. In the figure, B is an aggregate and C is a solidified cement paste.

Due to the voids A formed in the structure 1 as described above, the water permeability and heat insulating property of the structure 1 can be increased. That is, although the structure 1 formed of a base material such as concrete or mortar as described above has a certain amount of water permeability, the structure 1 may have a gap due to the voids A formed in the structure 1. Figure 4 above
Even in the state where they are independently dispersed as shown in (a), the flow of water is promoted by these voids, and it becomes possible to enhance the water permeability, and as shown in (b) of the figure, the voids A are separated from each other. Water permeability can be further improved in the case of communicating with each other.

As a result, for example, when water permeates the mine wall surface W from inside the natural ground G, the structure 1 first absorbs the water, and the water absorbed in the structure 1 is The waterproof material 2 does not penetrate into the secondary lining 3 side,
The structure 1 is discharged while sequentially moving downward in the structure 1.

In the above embodiment, the void-forming material was mixed into the concrete when forming the primary lining. However, the rope-shaped or mesh-shaped void-forming material was installed on the tunnel pit wall surface, and then the concrete was poured. It may be installed or sprayed. FIG. 5 shows an example thereof. As shown in FIG. 5 (a), the mesh-like void forming material 11 is arranged on the tunnel pit wall surface W, and then a base material such as concrete is sprayed to spray the same. As described above, the structure 1 is formed, and the water blocking material 2 and the secondary lining 3 are applied thereon.

The void forming material 11 is applied to the tunnel pit wall surface W.
When arranging the space, it may be fixed by a jig or the like not shown in the drawing, if necessary, and the position of the space forming material with respect to the tunnel pit wall surface W by the jig, that is, the pit wall surface W
The gap forming material 11 can be installed at a desired position in the thickness direction in the structure 1 by adjusting the separation distance from the.

The void-forming material 11 disposed in the structure 1 as described above is one that is water-soluble, heat-soluble, biodegradable or alkali-decomposed in the same manner as in the above-mentioned embodiment to form a void. In the present embodiment, by using the mesh-shaped void forming material, it is possible to form the mesh-shaped voids G communicating with each other as shown in FIG. The other configurations are similar to those of the above-described embodiment, and similar operational effects can be obtained.

As described above, by constructing the structure 1 according to the present invention in place of the shotcrete which is constructed as the primary lining on the tunnel wall W, the construction efficiency and the structure can be simplified. . That is, in the conventional waterproof construction of a tunnel, a blast wall concrete is used to cover the mine wall surface, and then a buffer layer made of a non-woven fabric of a predetermined thickness is laid, and a waterproof sheet such as a waterproof sheet or waterproof concrete is constructed on it. However, in the present invention, since the water permeability and the strength are secured only by forming the structure 1 as described above on the mine wall surface W, the above sprayed concrete is not necessarily required, and the structure A waterproof material 2 such as a waterproof sheet or waterproof concrete can be directly installed on the water-resistant material 1.

The permeability coefficient of the conventional water-permeable cushioning material is generally at a level of 10 ^-1 , and the drainage capacity may be insufficient if the amount of spring water increases due to seasonal factors, but in the present invention, the void-forming material is used. Since the water permeability can be arbitrarily controlled by appropriately adjusting the mixing ratio of, the structure 1 can be provided with high drainage property, if necessary.

Although the above-described embodiments exemplify the case of construction on the wall surface of the tunnel mine, the present invention can be applied to other building or construction structures. FIG. 7 is applied to a rock slope such as a cliff. For example, as shown in FIG. 7A, after the porous structure 1 according to the present invention is applied to the slope of the rock G, the weathering prevention concrete 5 is applied. If constructed, the spring water from the natural ground G can be entirely drained by the porous structure 1.

Conventionally, since the weathering-preventing concrete 5 was sprayed directly on the above-mentioned ground slope, a water channel is formed on the back surface thereof, the ground flows, and the back surface of the sprayed concrete 5 with the passage of time. There is a risk that cavities may occur in the surface or surface slips may occur.
By forming the ridge, spring water can be discharged while pressing the surface soil, and the slope can be protected stably for a long period of time.

FIG. 7 (b) shows a porous structure 1 formed by mixing plant seeds and nutrients on the ground slope, which has a function equivalent to that of conventionally known vegetation concrete and at the same time has a drainage function. Can be held. In this case, the seeds and nutrients may be mixed in the void-forming material 11 in advance and then mixed with the base material, or the seeds and nutrients and the void-forming material 11 may be separately mixed in the base material. Good.

FIG. 8 is applied to revetment work for rivers and coasts. For example, if the revetment of a river as shown in FIG. The erosion control revetment provided can be obtained. Also in this case, if the plant seeds and nutrients are mixed into the structure 1 in the same manner as described above, a revetment for vegetation can be obtained, and, for example, as shown in FIG. 8B, plant seeds and nutrients are mixed. If the porous structure 1 is formed into a block and placed in water or seawater, aquatic algae and seaweed can be grown.

FIG. 9 shows an example in which the present invention is applied to a road pavement. For example, the surface of a roadbed R laid with gravel or the like and solidified, for example, a porous material of the present invention using mortar or concrete as a base material. By forming the structure 1 in the same manner as described above and further forming a water-permeable surface layer 6 made of, for example, water-permeable asphalt concrete on the surface thereof, a paved road with good drainage can be obtained.

FIG. 10 shows a structure in which the porous structure 1 according to the present invention is used as a cushioning material. For example, an existing building or building (mascon) B made of concrete and a side surface of a ground G adjacent to it are provided. By interposing the porous structure 1 according to the present invention, the expansion and contraction of the concrete can be absorbed by the structure 1 and cracks and the like due to external restraint can be prevented.

FIG. 11 shows a structure in which the porous structure 1 according to the present invention is applied as a pressing embankment to the tunnel pit T1 and can be used in place of conventional lightweight concrete or the like. It can be used not only for the tunnel mouth, but also as a light embankment to prevent ground subsidence.

FIG. 12 shows the porous structure 1 according to the present invention interposed as an insulating material between the outer wall W1 and the inner wall W2 of a house, which is applicable not only to houses but also to condominiums and buildings. Further, FIG. 13 shows that the structure 1 is applied as a sound absorbing material by constructing the porous structure 1 according to the present invention inside the sound insulation wall Sw of the road R.

Further, the present invention can be applied to the case of constructing an underground building or a structure such as a subway or an underground common ditch by a conventionally known SMW method or the like. For example, as shown in FIG. 14, a protection wall Ws in the SMW method is used. If the flowing water passages (wells) for ascending or descending groundwater and the flowing water passages Ps penetrating the underground building or the structure C are formed by the porous structure 1 according to the present invention (not shown) Then, after construction, groundwater can be circulated in those structures.

The porous structure 1 according to the present invention is not limited to the case where it is applied on site, but it can also be applied on site after being formed into a panel shape, a block shape or other desired shape in advance in a factory or the like.

[0035]

EXAMPLE A premix mortar was used as a base material, and gelatin powder was formed into a fibrous shape as the void forming material 11 in the manner shown in FIG. 2 at a mixing ratio of a plurality of types to obtain a diameter of 50 mm and a height of 100 mm. A cylindrical porous structure 1 was prepared and various properties were examined. The results and characteristics of existing vegetation and paving porous concrete and cellular concrete are shown in Table 1 below as a result and as a reference example.

[0036]

[Table 1]

The values in Table 1 above are average values measured a plurality of times for each mixing ratio, and the compressive strength is the value on the 9th day of age. Furthermore, based on the above measured values, graphs showing the relationship with the mixing ratio are shown in FIGS.

When a water-soluble or heat-soluble material made of collagen such as gelatin or glue or a biodegradable material typified by polylactic acid fiber was used as the void forming material 11, this flowed out from the base material such as concrete. In this case, there is no concern that the environment such as the ground or rivers will be adversely affected.
It is possible to safely mix any amount of compounding depending on the required water permeability.

[0039]

As described in detail above, since the porous structure and the method for constructing the same according to the present invention have the above-mentioned constitutions, the void-forming material is in an undecomposed state when kneading the base material and the void-forming material. It has a shape such as a granular shape, a fibrous shape, a string shape, a rope shape, a capsule shape, a mesh shape, or the like, and its mixing amount and mixing mode can be arbitrarily set. Therefore, the amount of voids formed inside the completed water-permeable cured material and the arrangement state can be made desired according to the purpose. In particular, since the void-forming material can be kneaded and arranged at the site, quality control is easy not only in the case of factory production but also in the case of producing a porous structure by on-site casting, spraying or the like.

Further, since the voids are formed in the portion where the void forming material is arranged inside the structure, the periphery of the aggregate is surely covered with the paste of the base material, so that the aggregates are connected to each other. Will never be cut off. Therefore, the reduction of the strength of the material can be suppressed to the necessary minimum, and the necessary strength can be favorably maintained.

[Brief description of drawings]

FIG. 1 is a perspective view of an example in which a structure according to the present invention is formed on a tunnel pit wall surface.

FIG. 2 is an explanatory diagram showing an example of a case where a powdery void-forming material is formed into a fiber shape.

FIG. 3 is an explanatory diagram showing an example of a device configuration in which a base material and a void forming material are kneaded and supplied.

FIG. 4A and FIG. 4B are enlarged views of a part of the structure.

FIG. 5 is a perspective view of another example in which the structure according to the present invention is formed on the tunnel pit wall surface.

FIG. 6 is an enlarged view of a part of the structure.

FIG. 7 is an explanatory diagram of an example in which the porous structure according to the present invention is applied to a slope such as a cliff.

FIG. 8 is an explanatory diagram of an example in which the porous structure according to the present invention is applied to revetment work.

FIG. 9 is a cross-sectional view of an example in which the porous structure according to the present invention is applied to road paving.

FIG. 10 is a sectional view of an example in which the porous structure according to the present invention is applied as a cushioning material.

FIG. 11 is an explanatory view of an example in which the porous structure according to the present invention is applied as a lightweight embankment.

FIG. 12 is a sectional view of an example in which the porous structure according to the present invention is applied as a heat insulating material for a building.

FIG. 13 is a sectional view of an example in which the porous structure according to the present invention is applied as a sound absorbing material for a road sound insulation wall.

FIG. 14 is a cross-sectional view of an example applied as a water-permeable and water-permeable material of the SMW method according to the present invention.

FIG. 15 is a graph showing the relationship between the mixing ratio of the void forming material and the unit volume weight in the example.

FIG. 16 is a graph showing the relationship between the mixing ratio of the void forming material and the void ratio in the example.

FIG. 17 is a graph showing the relationship between the mixing ratio of the void forming material and the water permeability in the example.

FIG. 18 is a graph showing the relationship between the mixing ratio of the void-forming material and the compressive strength in Examples.

FIG. 19 is an enlarged view of a part of conventional porous concrete.

[Explanation of symbols]

1 structure 2 Water stop material 3 Secondary lining G Ground W tunnel wall

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) E04G 21/02 103 E04G 21/02 103Z E21D 11/10 E21D 11/10 A D // E21D 11/38 11 / 38 B (72) Hideki Takeuchi, Hideki Takeuchi 1534-1, Nishi-ku, Nishinasuno-machi, Nasu-gun, Tochigi Prefecture, Ltd., Technical Research Institute, Goyo Construction Co., Ltd. (72) Sadato Omori, 1534, Nishi-ku, Nishi-nasuno-cho, Nasu-gun, Tochigi Prefecture 1534 -1 Goyo Construction Co., Ltd. Technical Research Laboratory (72) Inventor Toru Hauma 2-5-10 Shiba, Minato-ku, Tokyo KFC Co., Ltd. (72) Inventor Yoshitaka Fukuda Ueno, Taito-ku, Tokyo 1- 10-10 Nitta Gelatin Co., Ltd. Tokyo Branch (72) Inventor Hirohito Suzuki 2-22 Futamata, Yao-shi, Osaka Prefecture Nitta Gelatin Co., Ltd. F term in Osaka factory (reference) 2D044 DC03 DC04 2D0 55 DA00 DB00 KB07 KB10 LA03 2E001 DD01 FA04 FA06 FA29 FA30 GA12 GA82 HA01 HA03 HA33 HE10 JA01 JA02 JA22 KA01 KA05 KA07 KA08 LA06 2E172 AA09 4G019 DA04

Claims (3)

[Claims] 1. A water-soluble, heat-soluble or biodegradable or alkali-decomposable void-forming material mixed in a base material such as concrete constituting a porous structure is dissolved in water, heat-dissolved or biodegraded. Alternatively, a porous structure having voids formed by contraction or disappearance by alkali decomposition in the structure. 2. A material for forming a porous structure, such as concrete, and a water-soluble, heat-soluble, biodegradable, or alkali-decomposable void-forming material are kneaded and cured, and the voids are formed. A method for constructing a porous structure, characterized in that a void is formed in the structure by shrinking or disappearing the material by water dissolution, heat dissolution, biodegradation or alkali decomposition. 3. A porous structure having a water-soluble, heat-soluble, biodegradable, or alkali-decomposable void-forming material disposed at the position where the porous structure is applied, and the above-mentioned structural body is provided so as to cover the void-forming material. In the structure by pouring or spraying the base material such as uncured concrete that constitutes it, and curing the base material, and shrinking or disappearing the void forming material by water dissolution, heat dissolution or biodegradation or alkali decomposition A method for constructing a porous structure, characterized in that voids are formed.