JP2018167421A - Method for producing expansible filler - Google Patents

Abstract

To provide a method for producing an expansible filler excellent in expansibility and also excellent in the volume shrinkage.SOLUTION: There is provided a method for producing an expansible filler comprising: a first step where first solid components at least including a solidification material, coal ash and sand and water are mixed to prepare slurry having a flow value of 260 mm or more and 450 mm or less; and a second step where the slurry is added and mixed with second solid components at least including an expansion material, a clay mineral and a surfactant to prepare an expansible filler, in which the addition amount of the second solid components is set in such a manner that the ratio of the mass of the water to the total mass of the powder components included in the first solid components and the powder components included in the second solid components is controlled to 60% or higher and 100% or lower.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing an expandable filler.

  Cement-based materials containing bubbles are used as fillers used for underground cavity filling, under-building cavity filling, underground buried backfilling, and the like. Among these types of fillers, those containing bubbles in a proportion of 20 to 65% by volume with respect to the total volume are particularly lightweight and may be referred to as lightweight fillers. This type of filler can reduce the load on the surrounding earth pressure and structures, and it is comparable in strength to the soil, so that it can be easily re-excavated as necessary. .

  Examples of the method of incorporating bubbles in the filler include, for example, a preform method (pre-foaming method) in which bubbles are created with a foaming agent such as a surfactant and air and mixed with the slurry, and the foaming agent is mixed into the slurry, and the mixture And a foaming method (a foaming method) in which a foaming material (expansion material) such as an aluminum metal powder is mixed in a slurry and gas is generated by a chemical reaction to form bubbles. Among these methods, the after-foam method has received particular attention in recent years because it has advantages such as no loss due to bubble breakage during pumping and injection, and the production amount of slurry can be reduced.

  Examples of the technique for producing a filler that can be reduced in weight using the after-form method include those described in the cited document 1 and the cited document 2.

  By the way, in the civil engineering field, an effective utilization of fly ash (coal ash) generated as a by-product in a coal-fired power plant or the like has been attempted. Therefore, fly ash is used as an additive for the above-described filler for various purposes (for example, strength control, fluidity improvement, heat generation reduction, material cost reduction, etc.). In addition, since fly ash is easy to change in properties depending on the charcoal type, combustion conditions, and the like, normally, fly ash classified and selected that satisfies the standards such as JIS A6201 (2015) is used.

JP 2009-83413 A JP 2016-37431 A

  Even if a filler is produced using a slurry containing coal ash such as fly ash in addition to a solidified material such as cement by the after-foam method, the expandability is poor, and the volume may shrink after expansion. It was.

  In addition, it has been desired to provide a technology capable of effectively utilizing raw coal ash generated at a coal-fired power plant or the like (that is, unselected fly ash raw powder).

  The objective of this invention is providing the manufacturing method of the expansible filler which was excellent in expansibility, and excellent in suppression to volume shrinkage.

Means for solving the above problems are as follows. That is,
<1> A first step of mixing a solidified material, a first solid component containing at least coal ash and sand, and water to prepare a slurry having a flow value of 260 mm or more and 450 mm or less, and the slurry, A second step of preparing an expandable filler by adding and mixing a second solid component containing at least an expansion material, a clay mineral, and a surfactant, and the amount of the second solid component added is the first solid component An expandable filler that is set so that a ratio of the mass of the water to the total mass of the powder component contained in the component and the powder component contained in the second solid component is 60% or more and 100% or less Production method.

  <2> The method for producing an expandable filler according to <1>, wherein the expandable material, the clay mineral, and the surfactant are powder materials mixed with each other.

<3> The flow value of the expandable filler is 200 mm or more and 350 mm or less.
The manufacturing method of the expansible filler as described in 1> or <2>.

  <4> Said <1> to which said clay mineral is blended at a ratio of 5 to 50 parts by mass and said surfactant is 0.01 to 0.5 parts by mass with respect to 1 part by mass of said expansion material. <3> The method for producing an expandable filler according to any one of the above.

  <5> In the first step, the slurry is prepared by mixing the first solid component and the water in a plant mixer, and in the second step, the slurry prepared in the plant mixer is accommodated. The method for producing an expandable filler according to any one of <1> to <4>, wherein the second solid component is added to and mixed with the slurry in an agitator track.

  <6> The method for producing an expandable filler according to any one of <1> to <5>, wherein an expansion ratio of the expandable filler is 1.1 or more.

  <7> The powder component of the first solid component includes a fine powder component derived from sludge water, and the water includes water derived from the sludge water, and any one of <1> to <6> The manufacturing method of the expansible filler as described in one.

  <8> The method for producing an expandable filler according to any one of <1> to <7>, wherein the expandable material includes an aluminum powder whose surface is coated with a fatty acid.

  <9> The method for producing an expandable filler according to <8>, wherein the median diameter of the aluminum powder is 27 μm to 35 μm.

  <10> The method for producing an expandable filler according to any one of <1> to <9>, wherein the clay mineral includes bentonite modified with sodium or soda ash.

<11> method for producing expandable filler material according to any one of the said bulk density of the clay mineral is ^{0.3g / cm 3 ~0.6g / cm 3} <1> ~ <10>.

  <12> The method for producing an expandable filler according to any one of <1> to <11>, wherein the surfactant includes an anionic surfactant.

  According to this invention, the manufacturing method of the expansible filler which was excellent in expansibility and excellent in suppression to volume shrinkage can be provided.

Flow diagram of the method for producing the expandable filler of the present invention Explanatory drawing which shows the manufacturing method of the expansible filler using a raw plant and an agitator truck

(Expandable filler)
The inflatable filler according to this embodiment is a kind of filler using an after-foam method (post-foaming method), and is used for underground cavity filling, under-building cavity filling, underground buried backfilling, and the like. The inflatable filler is in a state in which the expansion is suppressed for a predetermined time after preparation and has an appropriate fluidity, and is easy to perform pressure feeding and injection work. After being injected into a target space such as a cavity, it expands at a predetermined expansion ratio, and volume contraction is suppressed. The expandable filler is manufactured by the method shown below.

[Method for producing expandable filler]
The expandable filler of this embodiment is a first step of preparing a slurry having a flow value within a predetermined range by mixing water with a first solid component containing at least a solidifying material, coal ash, and sand; A second step of preparing an expandable filler by adding and mixing a second solid component containing at least an expander, a clay mineral, and a surfactant to the slurry (see FIG. 1).

(First step)
The first step is a step of preparing a slurry, which is an intermediate material for producing an expandable filler, as shown in S1 of FIG. The slurry is prepared by mixing a first solid component containing at least a solidifying material, coal ash, and sand and water so that a flow value falls within a predetermined range.

  The first solid component is a general term for solid components added to water when preparing a slurry in the first step, and includes at least a solidifying material, coal ash, and sand.

  The solidifying material is a hydraulic or latent hydraulic material. Specifically, for example, cements (ordinary cement, early-strength cement, blast furnace cement, ultra-early-strength cement, intermediate heat cement, low heat cement, fly Ash cement), cement-based solidified material, lime-based solidified material, gypsum-based solidified material, recycled cement, recycled solidified material, and the like. These may be used alone or in combination of two or more. As the solidifying material, cement-based materials such as cements, cement-based solidified materials, and recycled cement are preferable, cements are more preferable, and ordinary cement, early-strength cement, and blast furnace cement are particularly preferable.

The coal ash is a substance generated in the process of burning coal. In the present embodiment, for example, coal ash that satisfies all the conditions (a) to (e) shown below is used.
(A) Silicon dioxide content is 35.0% by mass or more (b) Moisture content is 2.0% by mass or less (c) Ignition loss is 8.5% by mass or less (d) Density is 1. 85 g / cm ³ or more (e) Specific surface area of 1,400 cm ² / g or more

  A specific example of coal ash is fly ash. The fly ash may be a standard product satisfying a standard such as JIS A6201 (2015) or a non-standard product that does not satisfy the standard. Further, the non-standard product may be a non-standard product generated in a coal-fired power plant or the like (that is, unselected fly ash raw powder). Coal ash may be used in combination of multiple types, or may be used alone.

  Examples of the sand include natural sand, crushed sand obtained by pulverizing natural crushed stone, etc., reclaimed sand obtained by crushing concrete blocks, processed sand, artificial sand, volcanic sand (including crushed volcanic gravel), and the like. Can be mentioned. These may be used alone or in combination of two or more.

  The particle size of the sand is preferably 5.0 mm or less, and more preferably 1.5 mm or less. The particle size of the sand is measured in accordance with “Aggregate Screening Test Method” defined in JIS A 1102 (2014).

  By the way, most of the sand is composed of particles having a relatively large particle size used as an aggregate, but in the sand, there is a minute amount dispersed in water (in a slurry or in an inflatable filler). A component with a small particle size (hereinafter referred to as a fine powder component) is contained at a certain ratio. Such a fine powder component affects the flow value of the slurry and the expandable filler.

  Content (content rate) of the fine powder component contained in sand is calculated | required based on "the fine powder content test method of an aggregate" prescribed | regulated to JISA1103 (2014).

  As a 1st solid component, unless the objective of this invention is impaired, substances other than the solidification material mentioned above, coal ash, and sand may be utilized.

  As water used when preparing the slurry, for example, tap water is used. Moreover, as long as the objective of this invention is not impaired, water other than the said tap water may be utilized as water for preparing the slurry (for example, industrial water, ground water, recovered water generated in a ready-mixed plant, etc.). Moreover, you may use combining multiple types of water, and may use them independently.

  In the first step, the flow value of the slurry is set to a predetermined range described later by mixing the first solid component and water.

  In the present specification, the “flow value” of slurry, expansive filler, etc. is a measured value obtained by the method defined in JHS A313. A specific measurement method will be described later. The “flow value” of the slurry, the expandable filler, etc. is a measured value within 5 minutes after the addition of various components is completed.

  The flow value of the slurry prepared in the first step is 260 mm or more, preferably 280 mm or more, more preferably 300 mm or more and 450 mm or less, preferably 430 mm or less, more preferably 385 mm or less. When the flow value of the slurry is within such a range, material separation hardly occurs and homogeneous mixing is possible in the second step.

  In the first step, the method of mixing the first solid component and water is not particularly limited as long as the object of the present invention is not impaired. For example, a concrete mixer, a batch mixer, a gravity mixer, a tilt drum drum mixer, and the like are publicly known. The method using the stirring apparatus of this is mentioned.

  Moreover, unless the objective of this invention is impaired, components other than a 1st solid component and water may be added to a slurry.

  As one embodiment, the solidification material is added at a ratio of 30 parts by mass to 50 parts by mass with respect to 100 parts by mass of water, and the coal ash is a ratio of 60 parts by mass to 120 parts by mass with respect to 100 parts by mass of water. The sand may be added at a ratio of 20 parts by mass to 70 parts by mass with respect to 100 parts by mass of water.

  Moreover, the addition amount of the coal ash with respect to water may be larger than each addition amount of a solidification material or sand, and may be less conversely.

(Second step)
In the second step, as shown in S2 of FIG. 1, the slurry prepared in the first step is added and mixed with a second solid component containing at least an expanding material, a clay mineral and a surfactant, and then expanded. This is a process for preparing a conductive filler.

  The second solid component is a general term for solid components added to the slurry when preparing the expandable filler in the second step, and includes at least an expander, a clay mineral, and a surfactant. In the second step, the second solid component may be added as a powder, or the second solid component may be added in a state of being dispersed in a small amount of water in advance.

  The said expansion | swelling material is a material which generate | occur | produces a bubble (gas) in an alkaline system, For example, the metal containing powder containing metal powders, such as aluminum, magnesium, zinc, is mentioned. As such a metal-containing powder, an aluminum-containing powder containing an aluminum powder is preferable from the viewpoints of reaction stability, safety, and the like. In the present specification, the aluminum-containing powder includes those made only of aluminum powder. The reason why the aluminum powder generates bubbles in the aqueous alkaline system is that hydrogen gas is generated by the reaction of the following formula (1).

  The shape (grain shape) of the aluminum powder contained in the aluminum-containing powder is not particularly limited as long as the object of the present invention is not impaired, and may be scale-like, spherical, or the like. In addition, scaly particles having a median diameter of 10 μm to 50 μm and a fineness of aluminum powder are particularly preferable because the generation rate of bubbles is fast and uniform bubbles are easily formed.

  Moreover, as said aluminum containing powder, what coated the surface with fats and oils (resin component), such as a stearic acid, with respect to aluminum powder (For example, what coated the said fats and oils in the ratio of 3 mass% or less) It is preferable because it is easy to control the expansion of the expandable filler.

  Further, the median diameter of the aluminum powder (aluminum-containing powder) is not particularly limited as long as the object of the present invention is not impaired, but, for example, those in the range of 27 μm to 35 μm are used.

  Further, as the expansion material, the aluminum-containing powder may be used alone, or a material obtained by premixing the aluminum-containing powder and inert particles such as quartzite powder may be used.

  The clay mineral is used in combination with an expanding material and a surfactant, and is added to the slurry for the purpose of improving the dispersibility of the expanding material and ensuring the fluidity of the expanding filler. For example, bentonite is used as the clay mineral.

  Bentonite is an interlayer mineral and has a crystal structure in which sheets of atoms arranged in a plate form overlap each other, and has the property of incorporating other substances into the gaps between the sheets. Since water is also fixed between the layers and the crystals swell, bentonite can adjust the viscosity of the slurry (expandable filler), improve the dispersibility of the expander, and the like. Bentonite can be broadly classified into sodium-type bentonite in which sodium ions are adsorbed between layers and calcium-type bentonite in which calcium ions are adsorbed. The sodium type has higher swellability than the calcium type. Further, there is a modified bentonite obtained by treating calcium type with soda ash, and this modified bentonite is also highly swellable. In the present embodiment, it is more preferable to use sodium-type or modified bentonite because viscosity adjustment, dispersibility improvement, and the like are ensured with a small amount of addition.

The bulk density of the clay mineral is not particularly limited as long as they do not impair the object of the present invention, for ^example, it may be set in the range of ^{0.3g / cm 3 ~0.6g / cm 3} .

  The surfactant is used in combination with an expanding material and bentonite, and has a function of generating fine bubbles during mixing, a function of stabilizing bubbles generated by the expanding material in the slurry (expandable filler), and the like. It has. Specific surfactants include, for example, fatty acid surfactants, linear alkylbenzene surfactants, higher alcohol surfactants, anionic surfactants such as alpha olefin surfactants, and normal paraffin surfactants. An activator, an alkylphenol-type surfactant, etc. are mentioned. These may be used alone or in combination of two or more. Of these surfactants, anionic surfactants are preferred. In particular, alpha olefin sodium alpha olefin sulfonate is less affected by the temperature and temperature of kneaded water and deteriorates even in alkaline systems. It is preferable because it has properties such as difficulty.

  The expansion material, clay mineral, and surfactant may be added to the slurry separately, but the expansion material, clay mineral, and surfactant are added in the form of a powder that is premixed with each other. Is preferred. In this way, when the expansion material, clay mineral, and surfactant are premixed, when added to the slurry, it is easy to uniformly disperse and mix, and the flow value of the expandable filler can be easily controlled within a predetermined range. . In the case of pre-mixing, it is preferable to use a powdery (solid) surfactant, and it is particularly preferable to use sodium alpha olefin sulfonate powder.

  Further, the method of mixing the expansion material or the like is not particularly limited as long as the object of the present invention is not impaired. The method using an apparatus is mentioned.

  As the second solid component, a substance other than the above-described expansion material, clay mineral, and surfactant may be used as long as the object of the present invention is not impaired.

  The amount of the second solid component added to the slurry obtained in the first step is appropriately set according to the expansion ratio required for the expandable filler, and specifically, included in the first solid component. The ratio of the mass of water to the total mass of the powder component and the powder component contained in the second solid component is set to be within a predetermined range (for example, 60% or more and 100% or less).

  Examples of the powder component contained in the first solid component include a fine powder component contained in the solidification material, the coal ash, and the sand in a predetermined ratio. The total amount of the solidified material and the coal ash usually corresponds to the powder component contained in the first solid component. The “powder component” as used herein is a component having a minute particle size dispersed in water (in a slurry or in an expandable filler) like the fine powder component of sand, It affects the flow value.

  For example, when recovered water generated at a ready-mixed factory is used as water, a component having a fine particle size (fine powder component) contained in the water also corresponds to the “powder component” contained in the first solid component.

  Examples of the powder component contained in the second solid component include the expansion material, the clay mineral, and the surfactant. The expansion material, the clay mineral, and the surfactant generally correspond to the powder component contained in the second solid component.

  As described above, the “powder component” contained in the first solid component and the second solid component is a component having a minute particle size dispersed in water (in the slurry or in the expandable filler). It can be said that this affects the flow value of the filler.

  Since the slurry and the expandable filler have high viscosity, components other than the powder component (for example, sand other than the fine powder component) are dispersed in the slurry and the like. Such a component has little influence on the flow value of the slurry or the like.

  The ratio of the mass of water to the total mass of the powder component contained in the first solid component and the powder component contained in the second solid component (hereinafter sometimes simply referred to as “water / powder component ratio”). ) Is 50% or more, preferably 55% or more, more preferably 60% or more and 100% or less, preferably 95% or less, more preferably 90% or less. When the water / powder component ratio is in such a range, it has fluidity necessary for filling, and sedimentation of the sand component in the slurry is suppressed, and it is difficult for a density difference in the vertical direction to occur.

  The flow value of the expandable filler obtained by the second step is preferably 200 mm or more, more preferably 230 mm or more, still more preferably 250 mm or more, preferably 350 mm or less, more preferably 340 mm or less. is there. When the flow value of the expandable filler is in such a range, the generation of bubbles is not suppressed by the fluidity, and the bubbles are held in the slurry without rising due to buoyancy and degassing.

  In the second step, the method for mixing the second solid component and the slurry is not particularly limited as long as the object of the present invention is not impaired. For example, a concrete mixer, a batch mixer, a gravity mixer, a tilt drum drum mixer, and the like are publicly known. The method using the stirring apparatus of this is mentioned.

  As one embodiment, 5 to 50 parts by mass of a clay mineral and 0.01 to 0.5 parts by mass of a surfactant may be added to 1 part by mass of the expansion material, respectively.

  Moreover, unless the objective of this invention is impaired, components other than a 2nd solid component may be added to an expandable filler.

  In addition to the solidifying material, coal ash, sand, expanding material, clay mineral, surfactant, and water, the components added to the expanding filler within a range not impairing the object of the present invention include, for example, slag powder. Stone powder, lime powder, fine aggregate, mud and the like.

  Here, an example of a method for producing the expandable filler will be described with reference to FIG. FIG. 2 is an explanatory view showing a method for producing an expandable filler using a raw concrete mixer and an agitator truck. Reference numeral 10 in FIG. 2 represents a raw plant, and reference numeral 20 represents an agitator track. As shown in FIG. 2, the first step is performed in the green plant 10, and the first solid component 11 and water are mixed and stirred by the mixer of the green plant 10 to obtain a slurry.

  The slurry obtained in the raw plant 10 is put in the cargo room of the agitator truck 20, and the agitator truck 20 moves to the construction site. In addition, the slurry is appropriately stirred in the moving agitator truck 20. When the agitator truck 20 arrives at the construction site, the second solid component 21 is introduced into the cargo compartment of the agitator truck 20 via the receiving hopper. When the slurry and the second solid component in the cargo compartment are mixed and stirred for a predetermined time after the charging, an expandable filler is obtained. Thus, the second step is performed by the agitator track 20. The obtained inflatable filler is sent to the pump 30 via the receiving hopper, and further pumped by the pump 30 to be injected into a target place (a space to be filled). The pump 30 may be a built-in pump device or a mobile pump device such as a pump car.

  As described above, in the method for producing the expandable filler according to the present embodiment, the slurry is prepared in advance in a raw plant, the slurry is transported to the construction site by an agitator truck, and the final product is inflatable filling at the construction site. It is possible to produce a material. Therefore, in the method for producing the inflatable filler according to the present embodiment, the inflatable filler can be produced by using the cargo room of the agitator truck without requiring large-scale equipment at the construction site. Etc.

  As described above, in the expandable filler obtained by the method for producing an expandable filler of the present invention, each component is homogeneously mixed and dispersed, and problems such as breathing (water floating due to material separation) are also generated. It is suppressed.

  Further, the expansion ratio of the expandable filler can be appropriately set according to the purpose, and can be set to 1.1 or more, for example. The upper limit of the expansion ratio of the expandable filler is not particularly limited as long as the object of the present invention is not impaired, but is set to 2.2 or less, for example.

  Hereinafter, the present invention will be described in more detail based on examples. In addition, this invention is not limited at all by these Examples.

[Example 1]
(Preparation of slurry)
130 parts by mass of fly ash (an example of coal ash), 235 parts by mass of cement (an example of a solidified material), 230 parts by mass of sand (fine powder component: 7.5% by mass), 400 parts by mass of sludge water as recovered water (fine powder component: 8.7% by mass) and 65 parts by mass of water were stirred and mixed in a predetermined container to prepare a slurry.

The fly ash is fly ash raw powder, does not satisfy the standard of JIS A6201, has a silicon dioxide content of 55.6%, a moisture content of 0.1%, and an ignition loss of 5.6% by mass, The density is 2.27 g / cm ³ and the specific surface area is 2350 cm ² / g. The cement is a blast furnace cement type B, and the sand is reclaimed sand obtained by separating it from washing water of a ready-mixed concrete handling facility, and contains fine powder components in a proportion of 7.5% by mass. Aggregate. The sludge water is obtained by separating the washing water of the ready-mixed concrete handling equipment from sand and gravel, and is suspended water containing a fine powder component at a ratio of 8.7% by mass. In addition, the content rate of the fine powder component in sludge water is measured by the unit volume mass method.

(Flow test (before adding the second solid component))
The slurry was subjected to a flow test using a measuring method defined in JHS A313. Specifically, the slurry was slid into a cylindrical container (inner diameter 80 mm, height 80 mm) placed on a flat plate, and the spread (diameter) of the slurry when the cylindrical container was gently pulled vertically was measured. The measured value was the flow value. When the slurry does not spread in a perfect circle shape, the longest diameter and the shortest diameter are measured, and the average value is taken as the flow value. The results are shown in Table 2.

(Preparation of expandable filler)
In addition to the slurry, a powdered material obtained by previously mixing 14 parts by weight of bentonite (an example of clay mineral), 0.03 parts by weight of a surfactant, and 0.5 parts by weight of an expansion material is added and mixed. Thus, a slurry-like expandable filler was obtained.

  The bentonite is a soda ash modified product, the surfactant is an anionic surfactant sodium alpha olefin sulfonate (solid powder), and the expansion material is aluminum powder surface-coated with stearic acid. (Stearic acid content of 3.0% by mass or less, median diameter: 30 μm, flaky particles).

(Visual observation)
The property of the expandable filler immediately after the end of mixing (within 5 minutes after the end) was visually observed to confirm whether or not the material was homogeneously dispersed. The results are shown in Table 2.

(Flow test (after adding expansion material))
For the expandable filler immediately after the end of mixing (within 5 minutes after the end), the flow value was measured in the same manner as the measurement method described above. The results are shown in Table 2.

(Expansion magnification test)
The expansion ratio test of the expandable filler was performed by the method shown below. Specifically, first, within 5 minutes after the completion of mixing, a fixed volume of inflatable filler was sampled with a graduated cylinder, and the volume of the sampled expandable filler was defined as “initial volume”. Then, with the graduated cylinder still standing, measure the volume of the expandable filler every 30 minutes, and when the change in volume stops, the end of expansion is taken, and the volume at that time (“expansion end volume”) Measured. The expansion ratio was obtained from a calculation formula (expansion end volume / initial volume).

  In the expansion magnification test, the state of the expandable filler during expansion and the state of the expandable filler after standing for 6 hours after completion of expansion were visually observed. The results are shown in Table 2.

(density)
The density (g / cm ³ ) of the expandable filler after standing for 6 hours after completion of the expansion was measured. The results are shown in Table 2.

[Examples 2 to 5]
Except having changed the compounding quantity (mass part) of each component into what is shown by Table 1, it is the same as Example 1, and the slurry (before 2nd solid component addition) of Examples 2-5, and expansibility. A filler was produced. In Example 2, ordinary cement was used as cement instead of blast furnace cement. In Example 2 of Table 1, the symbol “(N)” was added after the blending amount of cement to indicate that ordinary cement was used. In Table 1, the symbol “(C)” was added after the blending amount of the expanding material to indicate that the expanding material was a surface-coated aluminum powder with stearic acid.

[Comparative Examples 1-5]
Except having changed the compounding quantity (mass part) of each component into what is shown by Table 1, it carried out similarly to Example 1, and produced the slurry and filler of Comparative Examples 1-5. In Comparative Examples 3 and 5, aluminum powder that was not surface-coated (resin-coated) was used as the expansion material. In Table 1, the symbol “(W)” is added after the amount of the expansion material of Comparative Example 3 and Comparative Example 5 to indicate that the expansion material is aluminum powder that is not surface-coated. In Comparative Example 4, aluminum powder having an oxide film formed on the surface by heat treatment was used. In Table 1, the symbol “(T)” was added after the amount of the expansion material of Comparative Example 4 to indicate that the expansion material was an aluminum powder having an oxide film formed on the surface by heat treatment.

  Moreover, about the expansible filler of Examples 2-5 and the filler of Comparative Examples 1-5, it carried out similarly to the said Example 1, and performed various tests and measurements. The results are shown in Table 2.

  As shown in Table 2, in Examples 1 to 5, the flow value of the slurry before the second solid component (expansion material or the like) was added and mixed was in the range of 320 mm to 380 mm. The properties of the expandable fillers of Examples 1 to 5 were all in a homogeneously mixed state, and no suspended matter was observed. Moreover, the flow values of the expandable fillers of Examples 1 to 5 were in the range of 250 mm to 325 mm, and the expansion ratio was 1.65 or more. In Example 1 and Example 2, the type of cement used was changed, but both showed the same expansion ratio.

  In the filler of Comparative Example 1, the ratio of “water / powder component ratio (mass ratio) is higher than that in each Example. The properties of the filler immediately after the completion of the mixing (within 5 minutes after the completion of mixing) were in a homogeneously mixed state, as in each example, however, the filler of Comparative Example 1 was 5 minutes after the completion of mixing. Since the material separation occurred and water bleeding (breathing) was observed from the time after passing through, the bubbles generated by the reaction of the expanding material floated and defoamed in the filler of Comparative Example 1. The magnification was remarkably reduced, resulting in a higher density of the finally obtained filler.

  The filler of Comparative Example 2 has a “water / powder component ratio (mass ratio) ratio lower than that of each Example. Such a filler of Comparative Example 2 has a high viscosity and a flow. The result was a low value: resistance to expansion occurred due to high viscosity, gas began to escape immediately before the end of expansion, and eventually a phenomenon (15% volume contraction) of the expanded filler contracted was observed. It was.

  The filler of Comparative Example 3 is a case where aluminum powder without surface coating (resin coating) is used as the expansion material. In addition, since the surface of the aluminum powder is hydrophilic (because it is not hydrophobic), in Comparative Example 3, no bentonite or surfactant is added. In such a filler of Comparative Example 3, fine bubbles were generated in the slurry immediately after the expansion material was added to and mixed with the slurry. That is, in Comparative Example 3, it is presumed that the reaction of the expansion material has already started during the stirring of the slurry. Moreover, in Comparative Example 3, a situation where defoaming was observed during expansion was observed. As a result, the expansion ratio was lowered, and volume contraction (about 5% volume contraction) was also observed after the expansion was completed.

  The filler of the comparative example 4 is a case where the aluminum powder in which the oxide film was formed by heat processing was used as an expansion | swelling material. In Comparative Example 4, the start of the foaming reaction by the expansion material was remarkably delayed, the breathing due to solid-liquid separation occurred, and the final expansion ratio was extremely low.

  The filler of the comparative example 5 is a case where the aluminum powder without surface coating (resin coating) is used as an expansion material like the comparative example 3. In Comparative Example 5, unlike Comparative Example 3, bentonite and a surfactant are added as in Example 1. In the filler of Comparative Example 5, the foaming reaction started early as in Comparative Example 3, and a defoaming phenomenon in which coarse bubbles floated upward was also observed. Further, after the end of expansion, a volume shrinkage of about 5% was also observed.

Example 6
Raw concrete mixer with 300 parts by weight of fly ash raw powder, 145 parts by weight of blast furnace cement, 100 parts by weight of recycled sand (fine powder component: 7.5% by weight), and 483 parts by weight of sludge water (fine powder component: 8.7% by weight) And stirred and mixed to prepare a slurry. Next, the obtained slurry was put into a loading chamber (agitator) of an agitator truck. After the addition, they were stirred at a low speed (1 rpm) for 30 minutes, and then 14 parts by mass of bentonite, 0.03 parts by mass of a surfactant, and aluminum powder (expansion material) coated with stearic acid (resin coating). A premix expansion material (powder) prepared by mixing 5 parts by mass of powder in advance was put into the agitator and stirred at high speed (10 rpm) for 2 minutes. The material was obtained. The water / powder component ratio of the resulting expandable filler is 86.6%.

  Immediately after stirring, the slurry-like expandable filler was discharged from the agitator, and the properties of the expandable filler were visually observed, the flow test, the expansion ratio test, and the density measurement were performed in the same manner as in Example 1 described above. . Further, before adding the premix expansion material, a part of the slurry was discharged from the agitator of the agitator track, and the flow value of the slurry was measured in the same manner as in Example 1 described above. These results are shown in Table 4.

[Comparative Example 6]
By the same method as in Example 6 above, slurry was prepared using a raw concrete mixer, and the obtained slurry was put into an agitator (loading chamber) of an agitator truck. After charging, after stirring them for 30 minutes at low speed (1 rpm), 0.5 parts by mass of the same expansion material as in Example 6 was charged into the agitator and stirred for 2 minutes at high speed (10 rpm). A shaped filler was obtained. The water / powder component ratio of the resulting filler is 89.1%. In addition, since it was confirmed that the aluminum powder was floating on the surface of the slurry-like filler, the slurry-like filler was discharged from the agitator after further high-speed stirring for 2 minutes, and the above-described Example 1 In the same manner, visual observation of the properties of the filler, flow test, expansion ratio test, and density measurement were performed. Moreover, before adding the said expansion | swelling material, a part of slurry was discharged | emitted from the agitator of the agitator track | truck, and it carried out similarly to Example 1 mentioned above, and measured the flow value of the slurry. These results are shown in Table 4.

[Comparative Example 7]
In the same manner as in Example 6, a slurry was prepared using a raw concrete mixer, and the obtained slurry was put into an agitator of an agitator truck. After the addition, they were stirred at a low speed (1 rpm) for 30 minutes, and then a premix expansion material prepared by powder mixing 0.03 parts by mass of the same surfactant and 0.5 part by mass of the expansion material as in Example 6 was added to the agitator. The slurry-like filler of Comparative Example 7 was obtained by high-speed stirring (10 rpm) for 2 minutes. The water / powder component ratio of the resulting filler is 89.1%. As in Comparative Example 6, since it was confirmed that the aluminum powder was floating on the surface of the slurry-like filler, the slurry-like filler was discharged from the agitator after further high-speed stirring for 2 minutes. In the same manner as in Example 1 described above, visual observation of the properties of the filler, flow test, expansion ratio test, and density measurement were performed. Further, before introducing the premix expansion material, a part of the slurry was discharged from the agitator of the agitator truck, and the flow value of the slurry was measured in the same manner as in Example 1 described above. These results are shown in Table 4.

[Comparative Example 8]
In the same manner as in Example 6, a slurry was prepared using a raw concrete mixer, and the obtained slurry was put into an agitator of an agitator truck. After charging, after stirring them at a low speed (1 rpm) for 30 minutes, a premixed expansion material in which 14 parts by weight of bentonite and 0.5 part by weight of the expansion material as in Example 6 were mixed in advance was charged into an agitator, The slurry-like filler of Comparative Example 8 was obtained by high-speed stirring (10 rpm) for 2 minutes. The water / powder component ratio of the resulting filler is 86.6%. Immediately after stirring, the slurry-like filler was discharged from the agitator, and in the same manner as in Example 1 described above, visual observation of the properties of the filler, flow test, expansion ratio test, and density measurement were performed. Further, before introducing the premix expansion material, a part of the slurry was discharged from the agitator of the agitator truck, and the flow value of the slurry was measured in the same manner as in Example 1 described above. These results are shown in Table 4.

[Comparative Example 9]
Except that the blending amount of sludge water was changed to 380 parts by mass, a slurry was prepared using a raw concrete mixer by the same method as in Example 6, and the obtained slurry was put into an agitator of an agitator truck. . After the addition, they were stirred at a low speed (1 rpm) for 30 minutes, and then the same premix expansion material as in Example 6 was put into the agitator and stirred at a high speed (10 rpm) for 2 minutes. The material was obtained. The water / powder component ratio of the resulting filler is 69.4%. Immediately after stirring, the slurry-like filler was discharged from the agitator, and in the same manner as in Example 1 described above, visual observation of the properties of the filler, flow test, expansion ratio test, and density measurement were performed. Further, before the premix filler was charged, a part of the slurry was discharged from the agitator of the agitator truck, and the flow value of the slurry was measured in the same manner as in Example 1 described above. These results are shown in Table 4.

[Comparative Example 10]
In the same manner as in Example 6, a slurry was prepared using a raw concrete mixer, and the obtained slurry was put into an agitator of an agitator truck. After charging, after stirring them at low speed (1 rpm) for 30 minutes, 0.5 parts by mass of an expanding material made of aluminum powder without surface coating (resin coating) is charged into the agitator and stirred at high speed (10 rpm) for 2 minutes. A slurry-like filler of Comparative Example 10 was obtained. The water / powder component ratio of the resulting filler is 89.1%. Immediately after stirring, the slurry-like filler was discharged from the agitator, and in the same manner as in Example 1 described above, visual observation of the properties of the filler, flow test, expansion ratio test, and density measurement were performed. In addition, before introducing the filler, a part of the slurry was discharged from the agitator of the agitator track, and the flow value of the slurry was measured in the same manner as in Example 1 described above. These results are shown in Table 4.

  Table 3 shows the amount of each component used in Example 6 and Comparative Examples 6 to 10. Moreover, in Table 3, the symbol “(C)” is added after the amount of the expansion material in Example 6 and Comparative Examples 6 to 9, and the expansion material is obtained by surface-coating aluminum powder with stearic acid. showed that. In Table 3, the symbol “(W)” was added after the amount of the expansion material in Comparative Example 10 to indicate that the expansion material was an aluminum powder that was not surface-coated.

  As shown in Table 4, the slurry-like expandable filler of Example 6 was homogeneously mixed without the aluminum powder floating or lump due to insufficient stirring. The flow value was 280 mm, the expansion ratio was 1.67 after 2 hours, and no volume shrinkage was observed thereafter. Moreover, the flow value of the slurry of Example 6 (before adding the expansion material) was 345 mm.

  Although the slurry-like filler of Comparative Example 6 was stirred for twice as long as that of Example 6, the aluminum powder floated. Further, the flow value was 340 mm, and water floating (breathing) occurred 10 minutes after discharge, and the phenomenon that coarse bubbles floated on the upper part of the slurry-like filler during expansion was also confirmed. The expansion ratio was 1.39 after 2 hours. This is presumed that the aluminum powder was not homogeneously mixed in the slurry, so that the expansibility was lowered. In addition, the flow value of the slurry of Comparative Example 6 (before the expansion material was added) was 340 mm.

  In the slurry-like filler of Comparative Example 7, the aluminum powder floated. The flow value was 350 mm, and it was confirmed that coarse bubbles floated on the upper part of the slurry-like filler during expansion. The expansion ratio was 1.43 after 2 hours. This is presumed that the aluminum powder was not homogeneously mixed in the slurry, so that the expansibility was lowered. In addition, the flow value of the slurry of Comparative Example 7 (before the expansion material was added) was 340 mm.

  In the slurry-like filler of Comparative Example 8, although the aluminum powder did not float at the initial stage, water floating (breathing) occurred on the upper part of the slurry-like filler after 10 minutes had passed after discharge. did. In addition, although there was a small amount of aluminum powder, a phenomenon of floating on the surface of the slurry-like filler was observed. The flow value was 285 mm, foam breakage was confirmed during expansion, and the expansion ratio was 1.55 after 2 hours. In addition, the flow value of the slurry of Comparative Example 6 (before the expansion material was charged) was 340 mm.

  The slurry-like filler of Comparative Example 9 was homogeneously mixed without aluminum powder floating or lump due to insufficient stirring. The flow value was 220 mm, and the expansion ratio was 1.60 after 2 hours. However, after several hours had passed after the end of expansion, the filler of Comparative Example 9 had a volume shrinkage of 10%.

  The slurry-like filler of Comparative Example 10 was in a state where the foaming reaction had already started during the mixing, although it was homogeneously mixed without any lump due to aluminum powder floating or lack of stirring. The flow value of the filler of Comparative Example 10 was 180 mm, and the expansion ratio was 1.45 after 2 hours. Note that the filler of Comparative Example 10 eventually had a volume shrinkage of 6%. Since the expansion material used in Comparative Example 10 is not coated with the surface of the aluminum powder and the aluminum is exposed, the foaming reaction started immediately after the addition, and the foam was broken by the flow of discharge, etc. Presumed to have become smaller. Moreover, it is estimated that the volumetric shrinkage after expansion | swelling generate | occur | produced by the influence of coalescence etc. of bubbles.

  S1 ... 1st process, S2 ... 2nd process, 10 ... Raw plant, 11 ... 1st solid component, 12 ... Water, 20 ... Agitator truck, 21 ... 2nd solid component, 30 ... Pump

Claims (6)

A first step of mixing a first solid component containing at least a solidifying material, coal ash and sand and water to prepare a slurry having a flow value of 260 mm or more and 450 mm or less;
A second step of preparing an expandable filler by adding and mixing a second solid component containing at least an expander, a clay mineral, and a surfactant to the slurry; and
The addition amount of the second solid component is such that the ratio of the mass of the water to the total mass of the powder component contained in the first solid component and the powder component contained in the second solid component is 60% or more and 100. %. A method for producing an expandable filler that is set to be equal to or less than%.   The method for producing an expandable filler according to claim 1, wherein the expandable material, the clay mineral, and the surfactant are powder materials mixed with each other.   The method for producing an expandable filler according to claim 1 or 2, wherein the flow value of the expandable filler is 200 mm or greater and 350 mm or less.   The said clay mineral is 5-50 mass parts with respect to 1 mass part of said expansion | swelling material, and the said surfactant is respectively mix | blended in the ratio of 0.01-0.5 mass part. The manufacturing method of the expansible filler as described in any one. In the first step, the slurry is prepared by mixing the first solid component and the water with a plant mixer,
The said 2nd process WHEREIN: Addition mixing of the said 2nd solid component with respect to the said slurry is performed in the agitator truck which accommodates the said slurry prepared with the said plant mixer. A method for producing an expandable filler.   The method for producing an expandable filler according to any one of claims 1 to 5, wherein an expansion ratio of the expandable filler is 1.1 or more.

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