JP3141559B2 - Method for producing water-permeable cured material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention, between the relatively short time to cure, the solidified body can be formed of water permeable a porous well, and to exert the required strength after curing, the objective structure and soil
The present invention relates to a method for producing a water-permeable cured material to be filled .

[0002]

2. Description of the Related Art A material which is in a slurry state before curing and hardens with the passage of time to exhibit a predetermined strength, that is, a self-hardening slurry, has many uses in construction work. For example, it is widely used for filling hollows, filling gaps between excavated spaces and structures, backfilling retaining walls, backfilling pipeline laying work, backfilling hollows in pile heads, and the like.

[0003] The most common self-hardening slurries are concrete and mortar, and there is also a so-called soil mortar in which clay is mixed with mortar. These materials can arbitrarily control the fluidity by adjusting the amount of water and the like, and the solidification strength can be arbitrarily controlled by adjusting the amount of cement.However, it is not expected that the solidified product after curing has high water permeability. Can not.

[0004]

That is, if there is a self-hardening slurry capable of forming a solidified body having a required strength, a porous body having good water permeability after curing, there are various uses as follows. For example, it can be used as a material for a water-permeable fixing layer on the outer periphery of a reinforcing rod. By performing backfilling of the retaining wall with a permeable material, drainage can be performed smoothly and the earth pressure applied to the retaining wall can be reduced. By embedding the surface layer with a permeable material, rainwater can penetrate underground smoothly. In addition, it has water permeability, drainage, permeability, is lightweight, and can be used in general where a certain level of strength is required.

However, it is difficult to form a solid having high water permeability with the above-mentioned concrete and mortar. For example, in a “bubble mortar” in which a large amount of bubbles are mixed into a mortar, since the bubbles exist as closed cells in the solidified body, the water permeability is at most 10 ⁻³ to 10 ⁻⁴ cm / s, In addition, a considerable time is required until curing, and the curing period until reaching practical strength is long. Further, the compression strength of the solidified body can be obtained at most only about 10 kgf / cm ² .

[0006] Foamable urethane-based curing agents are:
When the isocyanate in the polyisocyanate prepolymer reacts with water, carbon dioxide is released, and the polymerization reaction proceeds. The generated carbon dioxide bubbles remain in the cured product after the reaction to form a porous solid.

[0007] The porous shape improves the water permeability and can exhibit the performance of the above-mentioned "water-permeable cured material". However, the strength of the cured product alone is too large, and the urethane-based curing agent is considerably expensive. Considering this, it is not suitable as a building material.

The present invention focuses on the performance of the above-mentioned urethane-based curing agent, and provides a variety of compositions which have the strength suitable for the above-mentioned various construction uses while having the advantages of the urethane-based curing agent, and which can be manufactured at low cost. As a result of the investigation, it was found that by dispersing the water-absorbing powder in the urethane polymer at an appropriate ratio, the solidified body formed in accordance with the mixing ratio has an appropriate water permeability and strength.

The present invention has been made based on the above findings, and has as its object to cure in a relatively short period of time, to be porous after curing, to have good water permeability, to have high compressive strength, and to be inexpensive. A method for producing a cured material is provided.

[0010]

To achieve the above object, according to an aspect of method for producing a water-permeable cured material of the present invention, the target structure
Method of producing a water-permeable cured material filled between the material and the soil
A slurry is formed by previously mixing a water-absorbing powder with water to form a slurry, and a foamable urethane-based curing agent containing a polyisocyanate prepolymer as a main component is added to and mixed with the slurry to form the urethane-based curing agent. The polymer is reacted while being foamed by reacting with water in the slurry, and the flow value before curing is 5-1.
0 cm, and forms a foamed solid in which the water-absorbing powder is dispersed in polyurethane formed by the polymerization after curing .

The water-absorbent powder is a mixture of one or more fine powders selected from cement, soil, fly ash, slag powder, various incinerated ash, water-absorbent resin and the like. In addition, a concrete retarder selected from lignin sulfonate, oxycarboxylate, polycarboxylate, naphthalene sulfonate and the like is added to the above.

In the present invention, a viscosity modifier can be added to the slurry. This viscosity modifier is composed of a thickener or a thickener. The thickener is selected from cellulosic polymers, polyacrylamide-based water-soluble polymers, and starch, and the thickener is ligninsulfonic acid. It is selected from salts, oxycarboxylates, polycarboxylates, and naphthalene sulfonates.

Next, the above materials will be described in more detail.

[Water-absorbing powder, curing retarder] The water-absorbing powder is a material for increasing the amount of water to be added, reducing the strength of the polyurethane foam alone, and reducing the cost. Suitable for, cement, soil. Then, in order to ensure fluidity before curing, a curing retarder is added as necessary.

As the cement, any of ordinary portland cement, early-strength portland cement, ultra-high-strength portland cement, blast-furnace cement, fly ash cement, silica cement, and special cement commercially available for ground improvement / solidification of waste, etc. But can be used. In a special case, a water-absorbing resin can be used.

Further, the mixing ratio with respect to the urethane-based curing agent can be variously set according to the water permeability and strength to be obtained according to the type of construction.

As the soil, various soils such as kaolin clay, alluvial clay, loam, bentonite, sandy soil, silty clay and the like can be used. The mixing ratio of these urethane-based curing agents can be variously set according to the water permeability and strength to be obtained according to the type of construction.

As the curing retarder, as described above, a curing retarder for concrete, for example, lignin sulfonate, oxycarboxylate, polycarboxylate, naphthalene sulfonate and the like can be used.

[Urethane-based curing agent] Urethane-based curing agents include one-pack type (one-shot) and two-pack type (two-shot)
There is. In the one-pack type, all the reaction components, additives, and the like are mixed, and a polyurethane foam is formed by mixing with water. The one-pack type is economical and more advantageous in terms of equipment than the two-pack type, but has the disadvantage that a large amount of heat is generated because the polymerization addition reaction proceeds at once. On the other hand, the two-pack type is composed of a main agent and an auxiliary agent, and the main agent is a polyisocyanate group prepolymer having an isocyanate group at the end by reacting an excess of diisocyanate and a polyol, and the auxiliary agent is a polyol or various catalysts. And the like. In the case of the two-pack type, a polyurethane foam is produced by mixing the base and auxiliary (usually 5% based on the base) and water (usually 20% based on the base). The two-pack type has advantages that the reaction proceeds more uniformly, generates less heat, and can use a curing agent such as an amine as compared with the one-pack type. Therefore, the urethane-based curing agent used in the present invention may be either a one-part type or a two-part type,
From the viewpoint of quality control, the two-pack type is preferable.

The strength (degree of softness to rigidity) of the polyurethane foam after curing can be adjusted by the molecular weight, the number of functional groups, and the like of the polyol in the urethane-based curing agent. In the present invention, since a hard foamed cured product is often required, a urethane-based curing agent corresponding thereto is selected.

[Viscosity Adjusting Agent] Among the viscosity adjusting agents, the thickening agent is one which is added in a small amount in order to store gas inside by increasing the overall viscosity and to increase the water permeability. Molecules, polyacrylamide-based water-soluble polymers, and starch.

Conversely, the viscosity reducing agent is added in a small amount in order to increase the pumpability by suppressing the overall viscosity, and the above-mentioned lignin sulfonate, oxycarboxylate and polycarboxylic acid are used. Salt or naphthalene sulfonate.

[0023]

The water-absorbing powder and water are mixed in advance, and a foamable urethane-based curing agent containing a polyisocyanate prepolymer as a main component is charged therein, whereby the urethane-based curing agent is mixed with the water-absorbing powder. While being mixed with the powder, it reacts with water to initiate polymerization while foaming. Immediately after the start of the reaction, it has fluidity and can be transported by pumping or the like.

After the completion of the reaction, a foamed solidified product in which the water-absorbing powder is uniformly dispersed in the polyurethane formed by polymerization is formed. Value is obtained.

In the case of manufacturing by a method other than the above-mentioned manufacturing procedure, the dispersion of the water-absorbing powder and the urethane-based curing agent, which are different materials, becomes non-uniform, and the control of the reaction time is inadequate. It is difficult to obtain appropriate fluidity, and the solidified material has a dumpling shape and does not have a uniform dispersion state.

Further, the mixing pan-type forced kneading mixer used for kneading the left officer mortar, biaxially forced kneading mixer and the like are used.

[0027]

EXAMPLES [Test Method] In each of the examples described below, the obtained slurry and solidified product were subjected to the following test items (1) to (6). (1) Flow value The slurry is filled in a container having an inner diameter of 3 cm and a height of 7 cm, and is immediately laid down. The distance of the slurry flowing out from the container head at that time was measured, and this was defined as a flow value. (2) Curing start time The slurry was put into a beaker, the slurry was occasionally pierced with a stick, and the curing condition was measured to determine the curing start time. (3) Maximum temperature The slurry was placed in a beaker, a thermometer was inserted, and the maximum temperature was measured. (4) Wet density The slurry was placed in a cardboard container having an inner diameter of 5 cm and a height of 30 cm. After curing, the container was removed one day later, and the cured product was molded to a diameter of 5 cm and a height of 10 cm, and the mass was measured. The wet density was determined. (5) Permeability the test item (4) cured product of the internal diameter 5 cm · height 50cm cylindrical container (without lids on the upper and lower surfaces), Tsu Grease so as not to cause a gap between the cured product and container I set it. This was put into water together with the container to expel air bubbles inside the cured body, then the container was installed vertically, water was poured into the upper part of the container, and the outflow rate of water was measured. Then, the hydraulic conductivity was calculated from Darcy's law. (6) Uniaxial compressive strength The cured body after the test of the above test item (5) was subjected to JIS A1
216, a uniaxial compression test was performed.

Embodiment 1 FIG. When urethane-based curing agent-cement-water-setting retardant is mixed: No. 1 to 16 in FIG. 1 were blended. In each case, water, water-absorbing powder, viscosity modifier, etc. are added and mixed in a Hobart mixer, and then a two-part urethane-based curing agent (main agent and auxiliary agent) is added and mixed to form a slurry. This was cured to form a foamed solid.

FIG. 1 shows the results of measuring the physical properties of the obtained slurry and solidified product. In the figure, No. 1 is a standard composition when no cement is contained.

The composition of No. 1 has a very good water permeability and can form a solid having high strength. However, in this formulation,
The cost is too high because a large amount of a urethane-based curing agent, which is expensive as a construction material, is used. After No.2, cement was mixed and the amount of water was increased accordingly.

Nos. 5 to 7 containing 200 g of cement per 300 g of a urethane-based curing agent (base agent) have reduced water permeability and strength as compared with No. 1; Can be. In addition, the flow value of the composition was 5 to 7 cm, which was lower than that of No. 1, but not to the extent that it could not be pumped. This was the same for Nos. 2 to 4 in which 100 g of cement was mixed. Therefore, the composition of Nos. 2 to 7 has large utility value in construction work.

Even No. 8 to No. 13 can be used when pumping is not performed and a very high water permeability is not required.

Nos. 14 to 16 are cases where a curing retarder (oxycarboxylate salt) is mixed, and the fluidity (flow value) can be improved by mixing the curing retarder.

Next, based on the above results, the relationship between the ratio of cement / urethane-based hardener and the uniaxial compressive strength is graphed in FIG. 2, and the relationship between the ratio of cement / urethane-based hardener and the water permeability is shown in FIG. graphed, it was studied proper positive formulation.

It should be noted, apply positive formulation, how to set the target value of physical property, and whether the target value is used in any application of material, or used in any construction process, by different. That is, in a certain application or construction method, even if the physical properties are incompatible, if the use or the construction method is changed, it may be suitable.

Here, the fluidity immediately after mixing can be pumped, the compressive strength after solidification is 15 kgf / cm ² or more, and the water permeability after solidification is larger than the order of 10 ⁻² cm / s. It was investigated suitable positive formulation in criterion that.

As a result, as shown by black and semi-black marks in FIGS. 2 and 3, from the viewpoint of fluidity (evaluated by the flow value shown in FIG. 1), the cement / urethane-based main agent = 0 to 1 .
0 matches. Further, from the viewpoint of strength, water / cement = 0.
3 to 0.5 (Water referred to herein is water obtained by subtracting the water required for the reaction of the urethane base, that is, 20% of the water required for the reaction of the urethane base, from the total water.)
Is suitable.

Further, from the viewpoint of the water permeability, the cement / urethane base agent = 0 to 0.7 is suitable. It is specified by the manufacturer that the urethane-based auxiliary agent / the urethane-based main agent = 0.05 and the amount of water required for the urethane-based reaction be 20%. In addition, the addition of the curing retarder improves the flowability, as shown in the flow values of FIGS.
6 is apparent from a comparison.

Embodiment 2 FIG. When a urethane-based curing agent-Kasaoka clay-water-thickening agent is mixed: Is the same as in FIG.
Nos. 17 to 26 were blended. As a result, the physical property values are as shown in FIG.

The Kasaoka clay is a clay that is collected in the Kasaoka district of Okayama Prefecture and contains montmorillonite and kaolinite as clay minerals and is used for muddy water adjustment in civil engineering works. No. 17-2 which mixed 100-400g of Kasaoka clay per 300g of urethane-based curing agent (main agent)
Sample No. 5 had a lower coefficient of permeability and strength than No. 1, but it is clear that with such physical properties, it can be used for an effective use. In addition, the flow value of this formulation is 5-1.
Although it was lower than No1 at 0 cm, it was within the range where pumping was possible.

No. 26 containing 1 g of a thickener retained a larger amount of internal gas than No. 17, and thus could form a solid having a low density and a high water permeability.

Next, the relationship between the ratio of the Kasaoka clay / urethane-based curing agent and the uniaxial compressive strength is graphed in FIG. 5, and the relationship between the ratio of the Kasaoka clay / urethane-based curing agent and the water permeability is shown in FIG. graphed in Figure 6, it was investigated proper positive formulation.

As a result, as shown by black and semi-black marks in FIGS. 5 and 6, from the viewpoint of fluidity (evaluated by the flow value shown in FIG. 4), Kasaoka clay / urethane base resin = 0 to 0. 0.
7 matches. Further, from the viewpoint of strength, Kasaoka clay / urethane base agent = 0-0.3 and water / Kasaoka clay = 0.4-0.7
(Determined by extending the straight line), or 0.3 to 0.7 and water / Kasaoka clay = 0.4 to 0.5 (Water used here is necessary for the reaction of the urethane base agent from the whole water. Water, that is, water obtained by subtracting 20% of water required for the reaction by the urethane base agent). Also, more than formulation in terms of permeability is suitable positive.

This embodiment is an example in which Kasaoka clay is used, and the compatible composition is suitable only for Kasaoka clay. That is, if the soil is different, there is a difference in the amount of water held by the soil. Therefore, the compatible composition including all soils that can be used is as follows: soil / urethane base agent = 0-2 water / soil = 0.1-2, which is estimated to be considerably wide.

Embodiment 3 FIG. When urethane-based curing agent-bentonite-water is mixed:
Example 1 was used as the manufacturing procedure. No. 2 in FIG.
7,28 formulations were implemented. As a result, the physical property values are as shown in FIG. Urethane-based curing agent (base agent) 300g
Nos. 27 and 28 with 20 g per bentonite are No.
Although the coefficient of permeability and the strength were lower than those of No. 1, it is clear that such physical properties can be used for an effective use. In addition, the flow value of this formulation is No. 1
, But within the range where pumping is possible.

Embodiment 4 FIG. When urethane-based curing agent-water-absorbing resin-water is mixed: No. 2 in FIG.
9, 30 formulations were carried out. As a result, physical property values are as shown in FIG. Urethane-based curing agent (base agent) 300g
No. 29 to 30 mixed with 3 g of a water-absorbent resin (trade name: Arasorb) had lower water permeability and strength than No. 1, but it is clear that these physical properties can be used for effective applications. . In addition, the flow value of this formulation was 8 to 9 cm, which was lower than that of No. 1, but within the range where pumping was possible.

Embodiment 5 FIG. When urethane-based curing agent-fly ash-water is mixed: Is the same as in FIG.
Nos. 31 and 32 were blended. As a result, the physical property values are as shown in FIG. Urethane-based curing agent (base agent) 30
Nos. 31 and 32 mixed with 200 g of fly ash (coal ash obtained from a coal-fired power plant) per 0 g have lower hydraulic conductivity and strength than No. 1, but with such physical properties, they can be used for effective applications. It is clear. In addition, the flow value of this formulation was 8 to 9 cm, which was lower than that of No. 1, but within the range where pumping was possible.

Embodiment 6 FIG. When urethane-based curing agent-blast furnace slag powder-water is mixed:
Example 1 was used as the manufacturing procedure. No. in FIG. 10
33 and 34 were blended. The physical properties are shown in Fig. 1.
0. Urethane-based curing agent (base agent) 30
Blast furnace slag powder per 0 g (fineness is approx.
No. 33 and 34 which mixed 200 g of 2,000 cm ² / g)
Although the permeability and the strength were lower than those of No. 1, it is clear that such physical properties can be used for an effective use. In addition, the flow value of this formulation is No. 1
, But within the range where pumping is possible.

Comparative example. FIG. 11 shows the compressive strength and the water permeability of the self-hardening slurry in each of the examples and various conventional self-hardening slurries in comparison with each other.

The materials compared were concrete, mortar,
Soil cement and aerated mortar, in the case of the present invention, reach practical strength in one day, have a very high water permeability compared to any material, and are suitable for shortening the construction period and rapid construction. , Among the problems to be solved by the invention.

[0051]

As described in detail in each of the embodiments, the water-permeable cured material obtained by the production method according to the present invention has the following effects. Viscosity, strength and water permeability can be arbitrarily adjusted depending on the construction purpose and application. Due to the action of the urethane-based curing agent, very large strength can be obtained in a short period of time, shortening the construction period, and is particularly advantageous when rapid construction is required. The material cost can be extremely reduced as compared with the case of manufacturing by mixing a urethane-based curing agent and water. The durability can be improved by mixing the inorganic substance as compared with the case where the urethane-based curing agent and water are used.

Further, according to the production method of the present invention, it is possible to obtain a foamed solid in a form in which a water-absorbing material as a heterogeneous material is uniformly dispersed in a polyurethane formed by polymerization. Physical properties can be obtained.

[Brief description of the drawings]

FIG. 1 is a table showing the composition and physical property values in Example 1.

FIG. 2 is a graph showing the relationship between the ratio of cement / urethane-based hardener and the uniaxial compressive strength in Example 1.

FIG. 3 is a graph showing a relationship between a cement / urethane-based curing agent ratio and water permeability in Example 1.

FIG. 4 is a table showing the composition and physical property values in Example 2.

FIG. 5 is a graph showing the relationship between the ratio of Kasama clay / urethane-based hardener and the uniaxial compressive strength in Example 2.

FIG. 6 is a graph showing the relationship between the ratio of Kasama clay / urethane-based hardener and water permeability in Example 2.

FIG. 7 is a table showing the composition and physical property values in Example 3.

FIG. 8 is a table showing the composition and physical properties in Example 4.

FIG. 9 is a table showing the composition and physical properties in Example 5.

FIG. 10 is a table showing the composition and physical properties in Example 6.

FIG. 11 is a table comparing the compressive strength and the water permeability of the present invention with various conventional self-hardening slurries.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C04B 24:28 14:10 18:08 18:14 24:18 24:26 24:20 24:38) (56) References JP-A-49-45967 (JP, A) JP-A-51-109926 (JP, A) JP-A-52-137426 (JP, A) JP-A-54-119528 (JP, A) JP-A-62-83386 ( JP, A) JP-A-57-135763 (JP, A) JP-B-53-31503 (JP, B2) JP-B1-55233 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , (DB name) C04B 38/02 C04B 28/02 C04B 24:28

Claims (7)

(57) [Claims] 1. Permeability filled between a target structure and soil
A method for producing a water- soluble curable material, comprising mixing a water-absorbing powder in water in advance to form a slurry, and adding and mixing a foamable urethane-based curing agent containing a polyisocyanate prepolymer as a main component in the slurry. The urethane-based curing agent is allowed to react with water in the slurry to polymerize while foaming, and the flow value before curing is 5 to 10 cm.
A method for producing a water-permeable cured material , comprising forming, after curing, a foamed solid in which the water-absorbing powder is dispersed in polyurethane formed by the polymerization. 2. The water-absorbent powder is a mixture of one or more fine powders selected from cement, soil, fly ash, slag powder, various incinerated ash, water-absorbent resin and the like. The method for producing a water-permeable cured material according to claim 1. 3. The method for producing a water-permeable cured material according to claim 1, wherein a curing retarder is added to the slurry. 4. The curing retarder may be a lignin sulfonate, an oxycarboxylate, a polycarboxylate,
The method for producing a water-permeable cured material according to claim 3, wherein the method is a concrete retarder selected from naphthalene sulfonate and the like. 5. The method for producing a water-permeable cured material according to claim 1, wherein a viscosity modifier is added to the slurry. 6. The viscosity modifier comprises a thickener, wherein the thickener is selected from cellulose-based polymers, polyacrylamide-based water-soluble polymers, and starch. The method for producing a water-permeable cured material according to claim 4. 7. The viscosity modifier comprises a viscosity reducing agent, wherein the viscosity reducing agent is selected from lignin sulfonates, oxycarboxylates, polycarboxylates, and naphthalene sulfonates. The method for producing a water-permeable cured material according to claim 4, wherein: