JP2018176432A - Foam slurry, porous hardening body, manufacturing method of foam slurry, manufacturing method of porous hardening body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide slurry for which no addition of high polymer material viscosity improver is necessary.SOLUTION: There is provided foam slurry including solidification material, foaming agent and sludge water obtained by separating washing water of equipment handling fresh concrete into sand and gravel.SELECTED DRAWING: None

Description

  The present invention relates to a foamed slurry, a porous cured body, a method for producing a foamed slurry, and a method for producing a porous cured body.

  A foamed slurry containing a solidifying material such as cement can be made into a porous cured body by curing the foamed slurry. And such a porous cured body is lightweight because it contains many voids, and is used in various applications because it has heat insulation and the like. For this reason, various studies have been conventionally made on a foamed slurry as a raw material.

  For example, Patent Document 1 discloses a porous sound absorption system in which a siliceous raw material, a calcareous raw material, and a foaming agent are mixed and stirred with water to obtain a slurry, the slurry is foamed, and open cells are formed and then cured by an autoclave. A method of making the material is disclosed. In addition, in patent document 1, methylcellulose, polyvinyl alcohol etc. are mentioned as a thickener.

Japanese Patent Application Laid-Open No. 9-301844

  However, for the slurry used in the method of manufacturing the porous sound absorbing material disclosed in Patent Document 1, for example, it has been necessary to use a special polymer material such as methyl cellulose as a thickener. Therefore, the production cost is increased, and there is a problem that the polymer material may remain in the porous body produced using the foamed slurry.

  Therefore, in one aspect of the present invention, it is an object of the present invention to provide a foamed slurry which does not require the addition of a thickener of a polymeric material, in view of the problems of the above-mentioned prior art.

According to one aspect of the invention, a solidifying material,
With a blowing agent,
Provided is a foamed slurry including sludge water obtained by separating washing water of fresh concrete handling equipment from sand and gravel.

  According to one aspect of the present invention, a foamed slurry can be provided without the need to add a thickener of a polymeric material.

The production flow figure of the sludge water in the embodiment of the present invention. Explanatory drawing of the usage example of the foaming slurry in embodiment of this invention.

Hereinafter, although the form for implementing this invention is demonstrated, this invention is not restrict | limited to the following embodiment, A various deformation | transformation and the following embodiment do not deviate from the scope of the present invention. Substitutions can be added.
[Foaming slurry]
In the present embodiment, one structural example of the foamed slurry of the present invention will be described.

  The foamed slurry of the present embodiment can include a solidifying material, a foaming agent, and sludge water obtained by separating washing water of a fresh concrete handling facility from sand and gravel.

  Each component contained in the foaming slurry of this embodiment is demonstrated below.

  The solidifying material is not particularly limited, and various solidifying materials can be used. As the solidifying material, for example, a cement-based solidifying material can be preferably used, and specifically, ordinary cement, blast furnace cement type B, early strength cement, fly ash cement and the like can be used.

  Among them, blast-furnace cement B which can suppress the elution of heavy metals can be preferably used as the foamed slurry of the present embodiment from the viewpoint of environmental problems.

  Next, the foaming agent will be described.

  It does not specifically limit as a foaming agent, What is necessary is just the material which can generate foam (bubble) in the mixture of a solidification material and the sludge water mentioned later. For this reason, various metal powders can be used. In particular, metal aluminum powder can be preferably used as the foaming agent.

  It is possible to stably generate a sufficient amount of bubbles in the slurry by using metal aluminum powder as the foaming agent, and after the bubbles are generated, the foamed slurry is in a stable state such as aluminum hydroxide. It is because it remains inside.

  Furthermore, according to the study of the inventors of the present invention, when metal aluminum powder is used as a foaming agent, it reacts with an alkaline component in the sludge water described later contained in the foaming slurry of the present embodiment, and in particular the function of foaming. It is preferable because it can be enhanced.

  The amount of the foaming agent added is not particularly limited, and can be arbitrarily selected according to the type of the foaming agent, the expansion coefficient required for the foamed slurry, and the like. According to the study of the inventors of the present invention, the addition amount of the foaming agent is in proportion to the expansion coefficient of the obtained foaming slurry, and the addition amount of the foaming agent, the obtained foaming slurry, The density of the cured body (porous cured body) is in inverse proportion to the density. For this reason, the expansion coefficient of the obtained foamed slurry and the density of the foamed slurry and the cured product thereof can be adjusted within the desired range by adjusting the addition amount of the foaming agent regardless of the sludge water concentration described later. .

When used, for example metallic aluminum powder as a foaming agent, the addition amount of metallic aluminum powder, in a proportion in the raw material, is preferably not more than 0.3 kg / ^{m 3} or more 1.5 kg / ^{m 3.}

  The foaming agent reacts with the water in the foaming slurry, in particular, the alkali component in the sludge water to foam, and after foaming is completed, it changes to another compound by reaction. For this reason, the foamed slurry of the present embodiment can include, for example, a solidifying material, a foaming agent, foams (foams) derived from the foaming agent, and sludge water while the reaction of the foaming agent proceeds. After the foaming by the foaming agent is completed, the solidified material, the foam derived from the foaming agent (bubbles), and the sludge water can be included. However, also in this case, a small amount of unreacted foaming agent may be contained.

  When preparing the foamed slurry, the method of adding the foaming agent is not particularly limited, and may be added and mixed simultaneously with other components. However, for example, in the case of adding powder or sand as an admixture to be described later, the foaming agent is mixed with one or more selected from the powder as an admixture and sand, and then mixed with other components. Is preferred. As described above, the foaming agent is dispersed particularly uniformly in the foaming slurry by mixing the powder as the admixture, fine particles of sand and the like and the foaming agent and then mixing with other components, so that the foaming slurry is In particular, uniform bubbles can be generated. For this reason, the porous cured body obtained by curing the foamed slurry can uniformly contain voids in the inside thereof.

  The foaming agent may be added to water or sludge water and then mixed with other components. Also in this case, since the foaming agent can be uniformly dispersed in water, it is possible to generate particularly uniform bubbles (bubbles) in the foaming slurry by further mixing with other components thereafter. For this reason, the porous cured body obtained by curing the foamed slurry can uniformly contain voids in the inside thereof.

  Next, the sludge water will be described.

  Sludge water is obtained by removing sand and gravel from the water produced when cleaning the cargo compartment of equipment used for handling fresh concrete, in particular the agitator car (mixer) used for transporting fresh concrete. It is a thing.

  Sludge water can be obtained, for example, by the operation flow shown in FIG.

  First, wash water (hereinafter, simply referred to as "wash water") from a fresh concrete handling facility is introduced into the aggregate classification facility.

  First, the washing water is passed through a vibrating sieve for gravel classification (for gravel recovery) to recover gravel having a large particle diameter. Next, the water dropped under a vibrating screen for gravel classification is supplied to a cyclone type classifier by a pump for classification, and then vibration for finer sand classification (for sand recovery) than when the gravel is classified. Recover sand by sieving.

  And what passed through the vibrating sieve for sand classification in this case is collect | recovered as sludge water.

  Sludge water can be obtained by the above steps. In addition, it is not limited to the operation concerned, It can be used without particular limitation if it is a method which can remove gravel and sand from washing water and recover sludge water.

  Moreover, concentrated sludge water can also be used in the foaming slurry of this embodiment. When concentrated sludge water is used as the sludge water, an operation of concentrating the obtained sludge water can be performed after the above-described steps. The method for concentrating sludge water is not particularly limited, and can be concentrated using, for example, a decanter.

  The sludge water obtained by the above-described steps contains water and a solid content contained in fresh concrete. Specific examples of solid content contained in ready-mixed concrete include cement, fine sand, limestone powder, and other dirt of sand and gravel used as an aggregate of ready-mixed concrete. It can contain one or more components selected from the inside.

  And the foaming slurry of this embodiment can contain a solidification agent, a foaming agent, and sludge water. The foam slurry of the present embodiment contains sludge water, so that bubbles (bubbles) generated by the foaming agent can be retained inside the slurry, and the form of the foam slurry can be maintained.

  Further, according to the studies of the inventors of the present invention, the foamed slurry of the present embodiment contains a sludge water, and the 28-year-old compression of the porous cured body obtained by curing the foamed slurry is obtained. The strength can be higher than the 28-day compressive strength estimated from the amount of solidifying material used.

  Furthermore, the foamed slurry of the present embodiment can suppress the bleeding rate to a small value by containing the sludge water, that is, can suppress solid-liquid separation. This is considered to be because the ratio of the water to be separated can be suppressed by using the sludge water for at least a part of the water to be added to the foaming slurry.

  The foamed slurry of the present embodiment can be added and contained with water alone, but it is preferable to add water (water) with sludge water without adding water alone. Addition of water with sludge water is preferable because it can particularly suppress the occurrence of solid-liquid separation during curing of the foamed slurry.

  Although the solid content concentration of the sludge water used for the foaming slurry of this embodiment is not specifically limited, For example, it is preferable that they are 3 mass% or more and 25 mass% or less.

  As described above, the addition of the sludge water makes it possible to keep the foam (bubbles) generated by the foaming agent in the slurry and maintain the form of the foamed slurry. In particular, when the solid content concentration of the sludge water is 3% by mass or more, in addition to the effect of retaining bubbles (bubbles) generated by the above-mentioned foaming agent in the slurry, solid-liquid separation between solid such as solidified material and water In particular, the effect of suppressing

  However, when the solid content concentration in the sludge water is higher than 25% by mass, handling of the sludge water may be difficult because the solid content concentration is high. Moreover, the sludge water which has not been concentrated has a solid content concentration of less than about 10% by mass, and a large amount of energy is required to concentrate the solid content concentration to be higher than 25% by mass. For this reason, it is preferable that solid content concentration in sludge water is 25 mass% or less from a viewpoint of improving handling property and suppressing cost.

  It is more preferable that solid content concentration of the sludge water used for the foaming slurry of this embodiment is 5 mass% or more and 20 mass% or less especially.

  In addition to the concentration, the solid content concentration of the sludge water can also be adjusted, for example, by adding water or adding the solid content of the dried sludge water.

  As described above, the foamed slurry of the present embodiment contains the sludge water, which eliminates the need to add a thickener such as a polymer material, which has been used in the conventional foamed slurry. Therefore, it is possible to suppress the remaining of the polymer material in the foamed slurry.

  In addition, as described above, sludge water can be produced easily from the water produced when cleaning equipment used to handle fresh concrete, so it can be easily obtained, further reducing costs. You can also

  As mentioned above, although the component contained in the foaming slurry of this embodiment was demonstrated, the component which the foaming slurry of this embodiment contains is not limited only to these components, As needed, various additives etc. Can also be added and contained.

  The foamed slurry of the present embodiment can also contain, for example, a powder as an admixture.

  The powder as the admixture is not particularly limited as to the material (material), but since it is added as an admixture, it does not include a cement or the like which reacts with alkali, water or the like to develop strength, It is preferable that the powder is harmless to the environment.

  Specific examples of the powder as the admixture include, for example, dewatered cake obtained by applying sludge water to a dehydrator, fly ash powder, electric furnace slag powder, waste incineration ash, sludge incineration ash, blast furnace slag, combustion slag, etc. One or more selected types can be preferably used.

  In addition, with "combustion slag", industrial wastes such as Mogara (waste plastic, food waste, paper waste, wood waste generated from construction site, industrial waste such as wood waste, combustible waste, etc. are burnt when general waste is burned in incineration facilities Ash is granular sand which is melted at a high temperature of 1300 ° C. or higher, poured into water and quenched. Further, “blast furnace slag” is produced as a by-product (such as an impurity in ore) when producing pig iron, and is separated by a specific gravity difference after being taken out in a molten state together with the pig iron.

  Among the above-mentioned materials, it is preferable to use a dewatered cake obtained by subjecting sludge water to a dehydrator as the powder as the admixture.

  This is because dewatered cakes obtained from sludge water have not many uses in recent years, and are often discarded as industrial waste. For this reason, it is preferable to use the dewatered cake as a raw material of the foamed slurry of the present embodiment, since it becomes possible to effectively reuse the material and to reduce waste.

The brane value of the powder as the admixture is not particularly limited, but the powder as the admixture preferably has a brane value of 2500 cm ² / g or more and 12000 cm ² / g or less, and 2500 cm ² / g or more and 11500 cm ² / g or less It is more preferable that It is preferable that the brane value of the powder as the admixture is in the above range, in particular, since each component can be uniformly dispersed in the foamed slurry. In addition, when the powder as the admixture having the above-mentioned brane value is added so as to be 2% or more and 17% or less in the ratio (weight ratio) in the raw material, each component can be dispersed particularly uniformly in the foamed slurry Because it is preferable.

When the powder as the admixture is added to the expanded slurry of the present embodiment, the amount (content) of the additive is not particularly limited, and it depends on the type of powder as the admixture, the solid content concentration of sludge water, etc. It can be selected accordingly. The amount of powder added as the admixture is preferably 50 kg / m ³ or more and 250 kg / m ³ or less in the proportion of the raw material of the foamed slurry. Moreover, it is preferable to add so that it may become 7% or more and 38% or less of a solidification material, for example in a weight ratio in the ratio with respect to a solidification material.

  The foamed slurry of the present embodiment can also contain sand.

  As sand, mountain sand, river sand, regenerated sand, or crushed sand can be used. In addition, as described later, part of the sand can be replaced by the powder as the admixture described above and used as mixed sand.

  The particle size of the sand is not particularly limited, but for example, the particle size is preferably more than 0 mm and 5 mm or less, and more preferably 0.075 mm or more and 5 mm or less.

  Sand can also be added as mixed sand partially mixed with, for example, powder as the admixture described above. Also when using as mixed sand, it is preferable that the particle size of mixed sand is 5 mm or less more than 0 mm, and it is more preferable that they are 0.075 mm or more and 5 mm or less.

  When the foaming slurry of the present embodiment contains sand, it is preferable that the proportion (weight ratio) in the raw material of the foaming slurry is 10% to 80%. In addition, as mentioned above, when substituting a part of sand with the powder as a mixing material and adding as mixed sand, it is preferable that the addition amount of mixed sand satisfy | fills the said range.

  In addition, the foamed slurry of the present embodiment can further contain paper powder.

  The foam slurry of the present embodiment contains sludge water, so that solid-liquid separation can be suppressed in the foam slurry. However, when sludge water with a low solid content concentration is used, the degree of suppressing solid-liquid separation may be low. In this case, the effect of suppressing such solid-liquid separation can be enhanced by adding the paper powder to the foam slurry.

  Paper dust is not limited to the case where the solid content concentration of sludge water is low. For example, even when the solid content concentration of sludge water is high, solid-liquid separation is further suppressed by adding paper dust. Can. For this reason, even if it is a case where solid content concentration of sludge water to be used is high, it can use suitably.

  Although the characteristic of the foamed slurry of the present embodiment is not particularly limited, for example, the expansion coefficient is preferably 20% or more in volume ratio. This is because the expansion coefficient is made 20% or more, that is, 1.2 times or more as compared with the case where the foaming agent is not added, and sufficient bubbles (bubbles) are generated and held in the foamed slurry. This is because when the foamed slurry is cured, a porous cured body having sufficient voids can be obtained.

  The upper limit of the expansion coefficient is not particularly limited, but is preferably 120% or less by volume ratio, and more preferably 105% or less. This is because when the expansion ratio exceeds 120%, that is, the volume exceeds 2.2 times as compared with the case where the foaming agent is not added, the ratio of foams (bubbles) becomes too large, and the porous cured body In the case of (1), there is a risk that the strength may be lowered.

  The expansion coefficient of the foaming slurry can be adjusted, for example, by the amount of the foaming agent added, the solid content concentration of the sludge water, and the like.

  The flow value of the foamed slurry of the present embodiment is preferably, for example, 200 mm or more and 430 mm or less. This is because when the flow value is 200 mm or more, the foamed slurry of the present embodiment can be easily poured into a mold or the like although it has sufficient fluidity.

However, if the flow value is greater than 430 mm, the flowability may be too high and the handleability may be reduced.
[Method for producing foamed slurry]
Next, the method for producing the foamed slurry of the present embodiment will be described.

  According to the method for producing the foamed slurry of the present embodiment, the foamed slurry described above can be produced, and therefore, the explanation of the matters already described is partially omitted.

  The method for producing the foamed slurry of the present embodiment can have a kneading step of kneading the raw material. And, the raw material can include at least a solidifying agent, a foaming agent, and sludge water obtained by separating washing water of fresh concrete handling equipment from sand and gravel.

  The kneading step is described below.

  In the kneading step, each component of the raw materials described above can be kneaded. In addition, the kneading | mixing means used in this case is not specifically limited, For example, when manufacturing fresh concrete, the various mixer normally used can be used.

  The raw materials used in the kneading step include at least the solidifying material, the foaming agent, and the sludge water as described above, but if necessary, powder, sand, water or the like as the admixture may be used as the raw material. It can also be used. The raw material can also contain paper dust as described above. About each component which comprises a raw material, since it is stated above, description is abbreviate | omitted.

  In the kneading step, the raw material solidifying material, the foaming agent, and the sludge water, and in some cases powder, sand, water, paper powder, etc. which are further admixtures can be simultaneously kneaded, for example, some components After kneading, the remaining components may be further added and kneaded.

  Specifically, for example, a foaming agent may be kneaded with one or more types selected from powder as an admixture and sand, and then may be kneaded with other components.

  Moreover, after adding a foaming agent to water or sludge water just before a kneading | mixing process, it can also knead | mix with another component.

As described above, the foaming agent is uniformly dispersed in the foaming slurry by kneading the foaming agent with powder, sand, water, sludge water, etc. as the admixture, and then with other components, so that the foaming slurry is uniformly dispersed. It is preferable because bubbles (bubbles) can be formed uniformly, and furthermore, voids can be uniformly formed in a porous cured body obtained by curing the foamed slurry.
[A porous cured product, a method of producing a porous cured product]
Next, the porous cured product of the present embodiment and the method for producing the same will be described.

  The porous cured body of the present embodiment is a cured body of the above-described foamed slurry.

  As described above, since the foamed slurry contains foams (bubbles) by the foaming agent, it is possible to obtain a porous cured body including voids by curing in a state including the foams (bubbles).

  Although the manufacturing method of the porous hardening body of this embodiment is not specifically limited, For example, it can have a hardening process of hardening the foaming slurry obtained by the manufacturing method of the foaming slurry as stated above.

  The specific operation in the curing step is not particularly limited, and can be arbitrarily selected according to the material of the solidifying material and the like. For example, when the solidifying material is various cements, no special operation is required in the curing step, and the cement can be cured by hydration reaction.

  In addition, after the curing step, the cast slurry is poured into a mold having a desired shape and a place where the porous cured body is to be placed, prior to the curing step so as to obtain a porous cured body having a desired shape. Etc. can be implemented arbitrarily.

  Here, an example of usage of the foamed slurry and the porous cured body according to the present embodiment will be described with reference to FIGS. 2 (A) and 2 (B).

  FIG. 2A shows a cross-sectional view in a plane perpendicular to the upper surface of the floor 11 (between soils) in which a gap 13 is formed between the floor (between soils) 11 and the ground 12 due to, for example, ground subsidence ing. As described above, when the air gap 13 is generated between the floor (the ground) 11 and the ground 12, the floor (the ground) 11 can not support its own weight, and there is a possibility that the floor 11 may sink. Therefore, as shown in FIG. 2A, an opening 14 is formed in the floor (intersoil) 11, and the foam described above is formed in the air gap 13 between the floor (intersoil) 11 and the ground 12 from the opening 14 By pouring the slurry 15 and curing it to form a porous cured body, the voids 13 can be filled with the porous cured body.

  In the case of using ordinary fresh concrete instead of the foamed slurry, solid-liquid separation or the like may occur and the void 13 may not be completely filled. For this reason, it may be necessary to inject fresh concrete in multiple times. On the other hand, solid-liquid separation can be suppressed in the above-described foamed slurry, and furthermore, the gaps can be self-filled by foaming, so that the voids 13 can be filled reliably.

  As an example of the foam slurry of this embodiment and another usage of the porous hardened body, the example shown in FIG. 2 (B) may be an example of filling the buried tank 22 buried underground below the ground 21. . In addition, a burial tank and various burial tanks are mentioned as a burial tank.

  The underground tank 22 buried underground requires a large amount of cost to dig out, but after it is not used, if left as it is, the wall portion of the ceiling surface of the underground tank may be broken due to corrosion or the like to cause depression or the like. Because of this, when it is no longer used, the hollow portion in the buried tank may be filled with a filler or the like. By using the foamed slurry of the present embodiment as the filler, the inside of the embedding tank 22 can be filled with certainty.

  Moreover, it can also be used as various construction materials as an example of the foam slurry of this embodiment, and the other usage form of a porous hardened | cured material. By molding the foamed slurry into a desired shape, for example, a plate-like shape and curing it, a plate-like porous cured body can be obtained. Since the porous cured body has voids uniformly inside, it can be used as a building material excellent in heat insulation and lightness. In addition, it may be used as a building material not only in the porous hardening body of this embodiment but in combination with other building materials, ie, a concrete board etc. which is not a porous body, and a plate-like porous hardening body, for example. it can.

  According to the foamed slurry and the porous cured body of the present embodiment described above, since it is not necessary to add a thickener of a polymer material, the foamed slurry according to the present embodiment and the porous cured product thereof are In the body, it is possible to suppress the retention of the polymeric material and to suppress the manufacturing cost.

Specific examples will be described below, but the present invention is not limited to these examples. In Experimental Examples 1 to 13 below, a foamed slurry and a cured product of the foamed slurry A porous cured body was produced. Experimental Example 1 to Experimental Example 12 are Examples, and Experimental Example 13 is a Comparative Example.
[Experimental Example 1]
Blast furnace cement type B (described simply as "cement" in Table 1) as a solidifying material and wash water of fresh concrete handling equipment were obtained by separating it from sand and gravel, and the solid content concentration was adjusted to 3% by mass Sludge water, a dewatered cake obtained by subjecting the sludge water to a dehydrator with a dehydrating value of 3400 cm ² / g, and a foaming agent which is metal aluminum powder are weighed and kneaded at a ratio shown in Table 1 to prepare a foamed slurry (Kneading process).

  The foaming agent was previously kneaded with the dewatered cake and then kneaded with other components.

  The obtained foamed slurry was evaluated for bleeding rate, flow value, and expansion rate.

  The bleeding rate was evaluated according to the Japan Society of Civil Engineers's Standard "Testing method of bleeding rate and expansion rate of injection mortar of prepacked concrete (JSCE-1986)".

  Specifically, the foamed slurry immediately after the kneading is filled in a predetermined polyethylene bag (diameter 5 cm, length 50 cm or more) so that air does not mix, put in a measuring cylinder containing 400 cc of water, and the surface and water level of the foamed slurry The initial volume is determined, and after 20 hours, it is measured in the same manner to measure the fall of the water level, and the bleeding rate is determined as a ratio to the initial volume.

  If the bleeding rate is large, large sedimentation will occur on the surface of the foamed slurry in the course of curing. Therefore, the smaller the bleeding rate of the foamed slurry, the better.

  The flow value was first filled on a 50 cm × 50 cm square iron plate into a cylindrical container (flow cone) having a diameter of about 80 mm and a height of about 80 mm prior to the start of foaming. Next, the bottom of the cylindrical container filled with the slurry was opened, and the cylindrical container was pulled up, and the diameter of the slurry spread on the iron plate was measured in two orthogonal directions.

  The coefficient of expansion is measured by putting the slurry before foaming starts in a measuring cylinder and measuring the volume (volume before foaming), and measuring the volume of the slurry (volume after foaming) when foaming of the slurry is completed, The volume after foaming was calculated by dividing by the volume before foaming. That is, it was calculated by the equation of (expansion factor) = (volume after foaming) / (volume before foaming).

  After the kneading step, the obtained slurry was poured into a cylindrical mold having an inner diameter of 50 mm and a height of 100 mm, and was foamed and cured to obtain a cylindrical porous cured body (curing step).

  The compressive strength of the test piece of the obtained porous cured body was measured at a material age of 28 days with a uniaxial compressive strength tester (a uniaxial tester (3 KN, manufactured by Ebara Corporation)).

  Moreover, the density of the obtained porous cured body was evaluated. The density was calculated by measuring the mass of the specimen before the test of the uniaxial compressive strength test of material age 28 and dividing the mass by the volume of the specimen.

From the surface and the cross section of the obtained porous cured body, the state of the voids in the porous cured body was visually confirmed.
[Experimental Example 2 to Experimental Example 6]
A foamed slurry and a porous cured product were produced in the same manner as in Experimental Example 1 except that the solid content concentration of the sludge water used was the concentration shown in Table 1, and the ratio of each component was the ratio shown in Table 1. And evaluated.
[Experimental Example 7]
The solid content concentration of the sludge water used was the concentration shown in Table 1, the dewatered cake was changed to sand, specifically, a point of using crushed sand having a particle size distributed between 0 mm and 5 mm or less, A foamed slurry and a porous cured product were produced and evaluated in the same manner as in Example 1 except that the proportions of the respective components were set to the proportions shown in Table 1.

In addition, the foaming agent was kneaded with other components after being kneaded with ground sand in advance.
[Experimental Examples 8 and 9]
The solid content concentration of the sludge water used is the concentration shown in Table 1, and the same as Experimental Example 1 except that the paper powder is further added to the raw material and the ratio of each component is the ratio shown in Table 1 The foamed slurry and the porous cured product were produced and evaluated.
[Experimental Example 10]
A foamed slurry and a porous cured product are produced in the same manner as in Experimental Example 3 except that a dewatered cake having a brane value of 9500 cm ² / g obtained by using a sludge water as a dewatered cake as the dewatered cake is produced and evaluated. went.

In addition, when preparing a foaming slurry, in order to set it as a flow value equivalent to Experimental example 3, as shown in Table 1, the quantity of a dehydration cake is reduced and the quantity of sludge water is increased.
[Experimental Example 11]
The foaming agent is not previously kneaded with the dewatering cake, and after mixing the components other than the foaming agent to prepare a slurry, the foaming agent is added to the slurry and foaming is performed in the same manner as in Experimental Example 4 except that mixing is carried out. The slurry and the porous cured body were manufactured and evaluated.
[Experimental Example 12]
The foaming agent is not previously kneaded with the dewatering cake, but after kneading components other than the foaming agent to prepare a slurry, a foaming slurry is prepared in the same manner as in Experimental Example 4, except that the foaming agent is added to the slurry. A porous cured body was produced and evaluated.

In addition, after the foaming agent was added to the slurry, it was hardly kneaded, and the foaming agent was poured into a mold while being partially solidified.
Experimental Example 13
Preparation of a foamed slurry was attempted in the same manner as in Experimental Example 1 except that the sludge water was not added. In addition, in Experimental example 13, it is set as the same mixing | blending as Experimental example 1, and water is added instead of sludge water. However, the foam slurry could not retain the cells in the slurry, and a foam slurry could not be obtained.

以上の実験例１〜実験例１２により得られた発泡スラリー及び多孔質硬化体は、特殊な高分子化合物である増粘剤を含有していない。このため、得られた発泡スラリーや、多孔質硬化体は、増粘剤に起因する成分を含有するものではない。それにも関わらず、発泡スラリーは気泡を保持することができることが確認できた。

The foamed slurry and the porous cured product obtained by the above-described Experimental Examples 1 to 12 do not contain a thickener that is a special polymer compound. For this reason, the obtained foamed slurry and the porous cured product do not contain the component resulting from the thickener. Nevertheless, it has been confirmed that the foamed slurry can retain air bubbles.

  In each of Experimental Examples 1 to 12, the bleeding rate was as high as about 0.3%, and it was confirmed that the occurrence of bleeding was sufficiently suppressed. The small amount of the bleeding rate in Experimental Example 2 means that although the occurrence of bleeding is observed, it is less than 0.3% and as close to 0% as possible. In particular, comparing experimental example 1 with experimental example 8 and experimental example 2 with experimental example 9 having substantially the same composition except that the paper powder is added, it is possible to particularly suppress the occurrence of bleeding by adding the paper powder. Was confirmed. Moreover, it has been confirmed that the compressive strength of the porous cured product is also increased by adding the paper powder.

  Moreover, it was confirmed that the porous cured body which is a cured body of the foamed slurry obtained in Experimental Examples 1 to 10 contains minute voids of substantially uniform size. However, after preparing the slurry which knead | mixes components other than a foaming agent, in Experimental examples 11 and 12 which added the foaming agent to this slurry, although it is slight, the size of the space | gap in the porous hardening body obtained is a product as There was a variation that did not cause a problem. It is considered that this is because the foaming agent was biased in the foaming slurry. For this reason, it has been confirmed that it is preferable to knead the foaming agent in advance with, for example, a dewatered cake before adding.

  On the other hand, in Experimental Example 13, a foamed slurry could not be obtained. This is because the foam generated by the foaming agent could not be retained in the slurry.

Claims (9)

Solidifying material,
With a blowing agent,
A foamed slurry comprising sludge water obtained by separating washing water of fresh concrete handling equipment from sand and gravel.   The foamed slurry according to claim 1, wherein the sludge water has a solid content concentration of 3% by mass or more and 25% by mass or less.   The foamed slurry according to claim 1 or 2, wherein the foaming agent is metal aluminum powder.   The foamed slurry according to any one of claims 1 to 3, further comprising paper dust.   The expanded slurry is 20% or more and 120% or less by volume ratio, The foaming slurry as described in any one of Claim 1 thru | or 4.   The porous hardened | cured material which is a hardened | cured material of the foaming slurry as described in any one of Claims 1-5. It has a kneading process to knead the raw materials,
A method for producing a foamed slurry, wherein the raw material comprises at least a solidifying material, a foaming agent, and sludge water obtained by separating washing water of a fresh concrete handling facility from sand and gravel.   The method for producing a foamed slurry according to claim 7, wherein the raw material further contains paper powder.   A manufacturing method of a porous hardening object which has a hardening process which hardens a foaming slurry obtained by a manufacturing method of a foaming slurry according to claim 7 or 8.

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