JP3007940B2 - Lightweight ground to be cast on soft ground and construction method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a light-weight ground poured on soft ground and a method for constructing the same, and more particularly, to a light-weight ground constructed on soft ground such as swamps and paddy fields. Also, the present invention relates to a lightweight ground which is suitable for temporary work and vehicle movement, and a construction method thereof.

[Problems to be Solved by Conventional Techniques and Inventions] Conventionally, when it is attempted to construct a ground having sufficient strength on a soft ground in a swamp, paddy field, or the like, the soft ground is usually prepared in advance by sand compaction, sand drain, or the like. After improving the strength of sand, sand and gravel were directly scattered and embanked.

However, with such a construction method, it is impossible to prevent land subsidence due to embankment, and in the worst case, an accident such as embankment material itself being buried in soft ground has often occurred.

Such accidents are caused by the weight of the embankment material being large and the strength of the embankment material being low. As a method of removing these, a method of using a lightweight material such as foamed concrete or styrene foam as a ground material is becoming widespread.

In the construction method using such a lightweight ground material, a solidified lightweight material is manufactured in a plant or the like, and then transported to a soft ground and applied. But,
The transportation required a great deal of labor and transfer equipment due to the light weight of the material, and there were many accidents in which the material was destroyed during transportation.

Furthermore, foamed styrene has drawbacks such as weakness to fire and organic solvents, and foamed concrete has a drawback that a predetermined strength cannot be obtained within a short time.

In addition, when water is present on the ground, using a slurry-based material may cause construction problems such as mixing with water.

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have made the present invention which solves the problems of the prior art.

That is, the present invention relates to (1) a light-weight ground placed on soft ground and (2) a construction method thereof.

First, (1) the invention of a lightweight ground to be cast on soft ground is a quick-setting method in which the gel time on soft ground is several seconds to several tens of minutes, and a compressive strength of several tons / m ² or more is exhibited in the long term after hardening. A lightweight ground that is cast on soft ground, characterized by being filled with a filling material in a formwork on a soft ground having a concave cross section formed by being cast and formed by scatter of lightweight material, (2)
The invention of the construction method has a gel time of several seconds to several tens of minutes, and expresses a compressive strength of several tons / m ² or more for a long time after curing, a cement, a foaming agent, a quick setting agent made of water glass, and A quick-setting light-weight material mainly composed of water is sprinkled on soft ground to form a light-weight base, on which a large number of light-weight pieces such as empty bottles and styrofoam are placed. This is a method for constructing a light-weight ground to be cast on soft ground, characterized by spouting and setting a light-weight or hardenable material.

In the above invention, the light-weight ground cast on soft ground has a gel time on soft ground of several seconds to several tens of minutes, and a quick-setting light weight that exhibits a compressive strength of several tons / m ² or more for a long time after hardening. It may be configured by filling a filling material into a form body on a soft ground having a concave cross section formed by casting and forming a material.

As the filling material, for example, dredged soil, may be filled with a so-called concrete-like composition which is a mixture of sand, gravel, cement, and water, and empty bottles, waste materials having a low bulk density such as empty cans, and the like. May be filled.

It is also preferable that a reinforcing material such as a net, a rope, or a fibrous body is provided on the lightweight ground of the present invention.

The use of a light-weight hollow body such as an empty bottle in the present invention combines both the assurance of the buoyancy of the lightweight ground and the effective use of waste.

In addition, the invention using the above-mentioned formwork allows a formwork made of a quick-setting lightweight material to be constructed on soft ground, and a conventionally used ground material such as sand or slurry material is put therein, Workability is improved.

In addition, the casting of the lightweight ground on the soft ground in the invention of the method may be performed by setting an impermeable or semi-permeable sheet or bag on a required area on the soft ground, and as a result, The construction ground may have an impermeable or semi-permeable sheet, bag, coating material such as a coating material on the bottom and / or side surfaces thereof.

Furthermore, in the method of constructing the ground to be placed on soft ground, the above-mentioned placing may be performed on the soft ground, or a required area on the soft ground may be separated by a partition wall such as a sheet pile or a steel pipe sheet pile. Is also good.

When partitioned by sheet pile or steel pipe sheet pile, a movable formwork is attached to the inner surface of the partition wall near the soft ground, and after the casting quick setting lightweight material hardens, by moving the movable formwork, It is also preferable to create a clearance between the partition wall and the hardening quick-setting lightweight material to release the adhesion generated between the two.

In any of the above methods, when constructing a lightweight ground to be cast on soft ground, the light pieces and wires,
A reinforcing material such as a rope, a net, a lightweight reinforcing material, a plastic fiber, a metal fiber, or the like may be provided, and a quick-setting lightweight material may be scattered and cast.

The quick-setting light-weight material according to the present invention is a light-weight material composition comprising a cement, a foaming agent, a quick-setting agent made of water glass, and a mixture containing water as a main component, in which bubbles are uniformly dispersed and contained. is there.

Since the gel time (time required for consolidation) of the quick-setting light-weight material is several seconds to several tens of minutes, the final mixing of the constituent components of the material is preferably performed in the vicinity of the casting location.

In particular, when the curing time of the quick-setting lightweight material according to the present invention is as short as several seconds to several tens of seconds, the mixing of the quick-setting agent, the catalyst, and the like is preferably performed immediately before the casting location. This facilitates the supply of the material slurry or the like by the hose and ensures the quick connection and installation on the water.

The mixing is carried out by arranging and discharging the tips of the feed hoses for each component so that they cross each other near the casting point, or by using a feed hose consisting of a double pipe. , And each component can be mixed and released from its tip.

Referring to the drawings, the method of placing a light ground for embedding a light piece according to the present invention will be described. First, as shown in FIGS. Then, the quick-setting light-weight material 3 is pressure-fed to the tip of the feed hose 2 and is scattered on the soft ground to form a plate-shaped light-weight base 4.

Therefore, as shown in the process charts of FIGS. 1 (A) to 1 (C), waste materials such as empty bottles and empty cans are placed on the lightweight floating base 4,
A lightweight piece 5 such as styrofoam is placed (B), and a quick-setting lightweight material 3 is further scattered thereon (C), and they are cast as if they were embedded. The operation may be performed repeatedly.

In addition, a casting method using a concave mold is shown in FIG.
(B) As shown in the figure, first, the quick-setting light-weight material 3 is sprinkled on the water surface to form a plate-shaped light-weight base 4, and then, as shown in the process diagrams of FIGS. 2 (A) to 2 (E). A peripheral wall 4 'is formed by embedding and casting the peripheral portion, thereby obtaining a soft ground mold 40 having a concave cross section (B). Thereafter, the filling material 6 is filled in the formwork 40 (D) to complete the lightweight ground 10 (E).

Needless to say, various fillers may be added to the quick-setting lightweight material.

EXAMPLES Next, the present invention will be described in detail with reference to examples.

First, preparation of a quick-setting lightweight material for placing on soft ground will be described.

Preferred composition examples and mixing ratios of the quick-setting lightweight material according to the present invention are preferably those of the composition of the foaming paste, the composition of water glass, and the mixing ratio as described below.

[A: Composition of foaming paste] Cement: 100 parts by weight, water: 30 to 200 parts by weight Foaming agent: 0.1 to 5 parts by weight Cell stabilizer: 0.1 to 5 parts by weight Cell amount: 250 to 900 / m ³ [b : Composition of aqueous solution of water glass] Water glass (JIS No. 3): 100 parts by weight Water: 30 to 200 parts by weight Gel time preparation (salts): 0.1 to 10 parts by weight {mixing ratio of liquid a and liquid b (weight ratio)} a: b = 1: 0.1 to 1: 3.5 The quick-setting light-weight material mixture sets in a few seconds to a few tens of seconds.

This gel time can be adjusted by the mixing ratio of the foaming paste and the water glass.

In this example, a quick-setting light-weight material having the following composition was prepared from the above-mentioned composition range, and was applied to the casting on soft ground.

[Composition of foam Paste cement: 100 parts by weight, water: 100 parts by weight Foaming agent: 0.7 parts by weight foam stabilizer: 0.1 parts by weight amount of bubbles: and 650 / m ³ and a foam paste Composition of waterglass solution Water glass (JIS No. 3): 100 parts by weight Water: 50 parts by weight Gel time adjuster (salts): 0.1 part by weight of a water glass aqueous solution mixed at a ratio of 1: 0.16 (weight ratio). The gel time of the mixture of the example was 5 seconds, the density of the cured product was 0.6 ton / m ³ , and the compression strength of the cured lightweight ground 60 seconds after casting was 0.1 kgf / cm ² . After 2 hours, the compressive strength was 3 kgf / cm ² .

It has been confirmed that this cured product does not settle for a long time.

Here, the components used in this example will be described.

Water glass as a quick setting agent Water glass is usually commercially available No. 3 water glass (Na ₂ O · 3SiO ₂
Aq) is used, but the water glass stock solution (SiO ₂ : 28-30)
_{%, Na 2 O: 9~10%} , remainder: water viscosity) is high, is as it is slow movement speed. Therefore, it is desirable to add water in advance to lower the viscosity of the water glass liquid and increase the moving speed. This is the same as the method of using water glass in the usual water glass-based chemical injection, and is a well-known matter. In addition, it is very difficult to mix a small amount of a stock solution of water glass (a quick-setting binder) with a large amount of foaming paste from the viewpoint of uniform mixing.

Foaming agent When the foaming agent is explained, also in the present invention, a foaming agent such as naphthalene colloid butylsulfonate or protein used in a usual cement-based mixture is used. For a general surfactant, the upper limit is about 5% of the cement weight. Preferably, it is 3% or less.

In order to reduce the density of the cured product to 1.0 ton / m ³ or less, 160
/ m ³ bubbles are required.

To obtain these bubbles, the foaming agent needs to be added at a rate of about 0.05% or more.
0.2% or more.

Amount of water The amount of water in the foaming paste is preferably 200% or less (particularly preferably 100% or less) from the viewpoint of strength development. Since the strength development is greatly affected by the amount of the foaming agent added, the optimum amount of water also changes.

Cement amount Although the initial strength increases with an increase in the unit cement amount, the strength can be expected even when the unit cement amount is about 50 kg / m ³ . The required initial strength of the soft ground cast-in structure depends on the application, but is preferably 0.5 kgf / cm ² or more from the point of handling. For this reason, a unit cement amount of preferably 150 kg / m ³ or more is required.

The ratio of cement to water glass It is a rapid agglomeration reaction that causes the materials to rapidly form, and the ratio of each material (cement to water glass) must be appropriate for this reaction to proceed.

When the amount of water glass is reduced, the strength is greatly reduced.
Water glass (JIS No. 3) needs at least 30% of cement.

Next, other foaming agents, quick-setting agents, and the like will be described in relation to the above components.

Examples of the foaming agents include naphthalene colloid butylsulfonate, gelatin, protein derivatives such as casein, saponin, resin soap, lauryl sulfate and the like.

In addition, as a quick setting agent, water glass, potassium dichromate,
Examples thereof include sodium fluorosilicate, sodium aluminate, aluminum chloride, and calcium chloride, with water glass being particularly preferred.

In addition, JIS No. 3 product (SiO ₂ content 28 ~
30%, Na ₂ O content 9-10%) is used.

The use of water glass as a quick setting agent is particularly suitable in terms of quick setting, strength development, safety, and the like.

In addition, cement is used as a hardening agent, which is particularly preferable for securing quick setting and long-term strength.

Next, according to the drawings, (1) an example of placing a lightweight ground in which a material is embedded and (2) an example of placing a lightweight ground using a lightweight formwork having a concave cross section will be described.

(1) Casting of light ground to embed a large number of light pieces First, as shown in FIGS. Mixing and preparation of a quick-setting light-weight material, and the quick-setting light-weight material 3
To the tip of the feed hose 2, scattered on the soft ground surface and cast a plate-shaped lightweight base 4, and then FIG. 1 (A)
(C) As shown in the drawing, a light piece 5 such as an empty bottle, an empty can, styrofoam or the like is placed thereon (B), and a quick-setting light-weight material 3 is sprinkled thereon (C) and embedded therein. It is cast as it is. The operation may be performed repeatedly.

In addition, in the mixing preparation of the quick-setting light-weight material, the mixture of the foaming agent and water is stirred to sufficiently foam, and the cement slurry is uniformly mixed with the mixture to form a foaming paste. It is preferable to mix a water glass aqueous solution as a binder.

(2) Example of Casting Light Ground Using a Formwork with a Concave Cross Section Also, a method of casting using a concave formwork is as follows: First, as shown in FIGS. The lightweight lightweight material 3 is scattered on the soft ground surface, and a plate-shaped lightweight base 4 is cast thereon. Then, as shown in FIGS. Is formed to obtain a soft ground formwork 40 having a concave cross section (B).

Next, the lightweight reinforcement 7 is fixedly arranged on the lightweight base 4 (C), and then the filling material 6 is filled in the formwork 40 (D) to complete the lightweight ground 10 (E). .

As described above, the quick-setting light-weight material for placing on soft ground according to the present invention is composed of an extremely simple composition material, and a general mixer, pump or the like for civil engineering can be used in the production thereof.

Then, the light ground can be easily cast by spreading the light ground on the soft ground as it is, and then the lightweight ground can be completed by placing a light piece on the light base and then spreading the quick-setting light material thereon.

Also, after the quick-setting light-weight material is scattered and the light-weight base is cast, the casting is repeated around the periphery and the surrounding wall is laid to form a concave-shaped formwork easily. By filling the material, for example, earth and sand, concrete, mortar, or the like, or the hollow material such as the empty bottle, the empty bottle, and the mortar, a large-volume, lightweight ground can be easily and inexpensively manufactured.

FIG. 3 shows an example in which a rope net 8 as a reinforcing material is disposed in the lightweight base 4 of the lightweight formwork 40 having a concave cross section.
FIG. 4 shows an example in which the rope net 8 is embedded in the filling material 6.

The lightweight ground constructed in this way, in which waste materials are buried in quick-setting lightweight materials, can reduce the production cost because waste such as empty bottles and empty cans can be converted to useful raw materials, and Depending on the amount of gas in the light piece, it can be made into an ultralight lightweight ground or a lightweight ground with an appropriate density.

The openings of empty bottles, empty cans, and the like are preferably closed by, for example, putting a lid on, so that gas leakage is almost completely eliminated, so that long-term buoyancy can be further improved. In addition, the quick-setting light-weight material used can be reduced, and the weight of the product lightweight ground can be further reduced.

In addition, in the case of using a lightweight formwork with a concave cross section cast on soft ground, it is excellent in water resistance and lightweight, and can secure mechanical strength. It can be filled with any kind of filling material. Therefore, the manufacturing cost and the manufacturing operation of the lightweight ground are facilitated.

The light ground on the soft ground constructed according to the present invention is embankment on the soft ground, construction of a road on the soft ground,
It can be applied to temporary backfill.

In addition, the constructed lightweight ground can be used as a movable structure as it is, or it can be used as a temporary base for the construction of fixed structures, thereby facilitating various operations on soft ground, which was conventionally difficult, easily and quickly. Becomes possible.

The construction of a lightweight ground by directly laying out such a casting material on a soft ground is a novel thing that has never been seen before.

[Effects of the Invention] As described above, the light-weight ground on soft ground according to the present invention can be directly mounted on soft ground at the site, can be constructed in a short time, and does not require a large temporary device as in the prior art. .

Further, since the lightweight ground of the present invention can be filled with any material as the filling material, the manufacturing cost can be reduced.

Also, the production of a formwork with a concave cross section is facilitated by laying out a quick-setting lightweight material on soft ground, placing a lightweight base, and repeating the placement around the periphery to build up the surrounding wall. it can.

In addition, the cement according to the method of the present invention, a foaming agent, a quick setting agent made of water glass and a quick setting light weight material containing water as a main component are lightweight and quickly set in a few seconds to tens of minutes, so on soft ground. It can be cast as it is, and a lightweight base as a base for lightweight ground can be easily constructed.

The lightweight ground constructed according to the present invention can be applied to embankment on soft ground, construction of a road on soft ground, temporary backfilling, and the like. In addition, it can be used as a movable structure as it is, and it can be widely used as a temporary structure for constructing fixed structures, which makes it easy and quick to perform various tasks on soft ground, which was difficult previously. Become.

Furthermore, quick-setting light-weight materials are obtained by foaming and expanding the raw materials at the time of casting, so that only a small amount of raw materials need to be brought to the site, so that the raw materials can be transported easily and at low cost. Become.

Furthermore, equipment such as a mixer and a pump necessary for carrying out the construction method of the present invention can be used as it is with an ordinary civil engineering machine, and there is no need to prepare special equipment.

[Brief description of the drawings]

1 (A) to 5 (B) show process explanatory diagrams of various embodiments of a light-weight ground placed on soft ground. 1: Work vehicle, 2: Feeding hose, 3: Quick setting light weight material, 4: Light weight base, 4 ': Perimeter wall, 5: Light weight piece, 6: Medium filling material, 7: Light weight muscle, 8: Rope Net, 10: Light ground, 40: Formwork with concave cross section

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E02D 3/00-3/12 E02D 17/18

Claims (6)

(57) [Claims] Claims: 1. Casting and forming of a quick-setting light-weight material that has a gel time of several seconds to several tens of minutes on soft ground and exhibits a compressive strength of several tons / m ² or more for a long time after hardening. A light-weight ground on soft ground, characterized by filling a filling material into a form body on soft ground having a concave cross section. 2. A quick-setting cement, foaming agent or water glass, which has a gel time of several seconds to several tens of minutes on soft ground and exhibits a compressive strength of several tons / m ² or more for a long time after hardening. Characterized by filling a filling material into a formwork on a soft ground with a concave cross section formed by spraying a quick-setting light-weight material mainly composed of an agent and water. Lightweight ground cast on the ground. 3. The light-weight ground on soft ground according to claim 1, wherein the filling material has a low bulk density. 4. A gel time of several seconds to several tens of minutes, and develops a compressive strength of several tons / m ² or more for a long time after curing.
A quick setting agent consisting of cement, a foaming agent, water glass and a quick setting light material mainly composed of water are scattered on soft ground to form a light base, and a large number of light containers such as empty bottles and styrofoam are formed thereon. A method of constructing a light-weight ground to be cast on soft ground, wherein the quick-setting light-weight material or the hardening material is scattered and placed so that pieces are placed and further embedded therein. 5. A quick-setting light-weight material having a gel time of several seconds to several tens of minutes and exhibiting a compressive strength of several tons / m ² or more for a long time after curing is scattered on soft ground to form a concave section. A method of constructing a lightweight ground to be cast on soft ground, characterized by floating and forming a formwork body on soft ground, and then filling and setting a filling material therein. 6. The gel time is several seconds to several tens of minutes, and a compressive strength of several tons / m ² or more is exhibited for a long time after curing.
Cement, foaming agent, quick-setting agent consisting of water glass and quick-setting lightweight material mainly composed of water are scattered on soft ground to form and form a concave-shaped form body on soft ground, and then A method for constructing a lightweight ground to be cast on soft ground, characterized by filling and placing a filling material therein.