Geopolymer composition and method for producing the same, geopolymer cured body and method for producing the same, and kit for preparing geopolymer composition

Abstract

To provide a kit for preparing a geopolymer composition which makes it possible to easily produce a geopolymer composition having both excellent fresh properties and excellent strength development.SOLUTION: Provided is a kit for preparing a geopolymer composition, comprising a first package containing a solid composition and a second package containing a liquid composition, wherein the solid composition comprises: silica fume (SF); an inorganic filler (F) comprising fly ash and finely ground blast furnace slag; and a retarder (Re), and the liquid composition comprises: an alkali hydroxide containing at least one selected from the group consisting of sodium hydroxide and potassium hydroxide; and water, wherein a water-reducing agent (Ad) and a defoaming agent (DF) are contained in at least one of the solid composition and the liquid composition, and the retarder (Re) contains at least one selected from the group consisting of an alkali metal gluconate and an alkali metal citrate.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a geopololymer composition, a method for producing the same, a cured geopololymer, a method for producing the same, and a kit for preparing a geopololymer composition.

Background Art

[0002] Geopolymer compositions that harden like concrete by treating amorphous materials such as coal ash with an alkaline solution are known. Geopolymer compositions can reduce CO 2 generated during production compared to ordinary cement. Examples of silica sources used in geopololymer compositions include liquids such as water glass and fillers such as silica fume. For example, in Patent Document 1, a method (in-situ dissolution method) of stirring sodium hydroxide with powders of coal ash and blast furnace slag and then gradually dissolving silica fume has been proposed to gain the setting time of the geopololymer composition and ensure the workable time.

[0003] In Patent Document 2, it has been proposed to use sodium gluconate as a setting retarder to ensure the workable time of the geopololymer composition.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the fresh properties and strength development of geopolimer compositions are usually in a trade-off relationship, it has been difficult to achieve both of these characteristics. Therefore, the present disclosure provides a geopolimer composition having good fresh properties and excellent strength development. Further, provided are a method for producing a geopolimer composition capable of easily producing a geopolimer composition having good fresh properties and excellent strength development, and a kit for preparing a geopolimer composition. Also provided are a geopolimer cured body having high compressive strength and a method for producing the same.

Means for Solving the Problems

[0006] One aspect of the present disclosure is a kit for preparing a geopolimer composition having a first package containing a solid composition and a second package containing a liquid composition, wherein the solid composition comprises silica fume (SF), an inorganic filler (F) containing fly ash and blast furnace slag fine powder, and a retarder (Re), and the liquid composition comprises an alkali hydroxide containing at least one selected from the group consisting of sodium hydroxide and potassium hydroxide, and water, and a water reducing agent (Ad) and an antifoaming agent (DF) are contained in at least one of the solid composition and the liquid composition, and the retarder (Re) contains an alkali metal gluconate and an alkali metal citrate, and provides a kit for preparing a geopolimer composition.

[0007] The degree of the retardation action varies depending on the type of the retarder. The kit for preparing the geopolimer composition contains an alkali metal gluconate and an alkali metal citrate as the retarder (Re). By combining such a plurality of retarders in this way, it acts well in balance on the improvement of fluidity and the promotion of curing, and a geopolimer composition having good fresh properties and excellent strength development can be easily produced. Such a geopolimer composition is particularly useful in applications where excellent workability and high compressive strength are required, such as construction sites and civil engineering sites.

[0008] One aspect of the present disclosure provides a geopolimer composition obtained by blending the solid composition and the liquid composition in at least the kit for preparing the above-described geopolimer composition. This geopolimer composition has both good fresh properties and excellent strength development properties.

[0009] One aspect of the present disclosure provides a cured geopolimer obtained by curing a blend of the solid composition and the liquid composition in at least the kit for preparing the above-described geopolimer composition. Since this cured geopolimer is obtained by curing the above-described geopolimer composition, it has high compressive strength.

[0010] One aspect of the present disclosure includes a first preparation step of preparing a solid composition containing silica fume (SF), an inorganic filler (F) including fly ash and blast furnace slag fine powder, and a retarder (Re), and a second preparation step of preparing a liquid composition containing at least one selected from the group consisting of sodium hydroxide and potassium hydroxide and water, and a blending step of obtaining a geopolimer composition by blending at least the solid composition and the liquid composition, wherein a water reducing agent (Ad) and an antifoaming agent (DF) are included in at least one of the solid composition and the liquid composition, and the retarder (Re) contains an alkali metal gluconate and an alkali metal citrate, and provides a method for producing a geopolimer composition.

[0011] In the method for producing the above-described geopolimer composition, the solid composition contains an alkali metal gluconate and an alkali metal citrate as retarders. By containing such retarders, it is possible to sufficiently increase the compressive strength at 28 days of age while maintaining high fluidity immediately after kneading the liquid composition and the solid composition in the blending step. In addition, the solid composition and the liquid composition can be prepared in advance, and the blending step can be performed when necessary to prepare the geopolimer composition. Therefore, with this production method, a geopolimer composition having both good fresh properties and excellent strength development properties can be easily produced.

[0012] One aspect of the present disclosure provides a method for manufacturing a geopolimer cured body, which has a curing step of curing a geopolimer composition manufactured by the above-described manufacturing method. Since this manufacturing method uses the geopolimer composition manufactured by the above-described manufacturing method for the geopolimer composition, it is possible to manufacture a geopolimer cured body having excellent workability and high compressive strength. Therefore, it is particularly useful in applications where excellent workability and high compressive strength are required, such as construction sites for construction and civil engineering.

Effects of the Invention

[0013] According to the present disclosure, it is possible to provide a geopolimer composition having good fresh properties and excellent strength developability. Further, it is possible to provide a method for manufacturing a geopolimer composition and a kit for preparing a geopolimer composition, which can easily manufacture a geopolimer composition having good fresh properties and excellent strength developability. Further, it is possible to provide a geopolimer cured body having high compressive strength and a method for manufacturing the same.

Modes for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present disclosure will be described. However, the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following contents. The symbol "~" used in the numerical range indicates a numerical range including the upper and lower limit numerical values. For example, "X~Y" indicates a numerical range of "X or more and Y or less". A numerical range in which the upper limit and / or the lower limit is replaced with the numerical values described in the examples is also included in the disclosure content of the present disclosure. The plurality of exemplified components or materials may be only one kind, or a plurality may be combined.

[0015] The kit for preparing a geopolimer composition according to one embodiment has a first package containing a solid composition and a second package containing a liquid composition. Since the first package and the second package are solid and liquid respectively, they can be transported smoothly by separating them. Since the solid composition and the liquid composition in the kit for preparing a geopolimer composition are separated without being mixed, they can be stably stored for a long time. Therefore, the kit for preparing a geopolimer composition is excellent in handleability.

[0016] For example, the first package and the second package may be physically separate. The first package and the second package may be linked by, for example, label display or an IC tag. The means of linking is not particularly limited. Such a kit for preparing a geopolimer composition can easily prepare a geopolimer composition by mixing a solid composition and a liquid composition immediately before using the geopolimer composition. The geopolimer composition prepared in this way has good fresh properties and excellent strength development. Also, CO 2 emissions can be reduced.

[0017] The solid composition includes silica fume (SF), an inorganic filler (F) including fly ash and blast furnace slag fine powder, and a retarder (Re). The retarder (Re) contains an alkali metal gluconate and an alkali metal citrate. The solid composition may contain components other than these. The solid composition preferably contains an alkali carbonate including at least one selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydrogen carbonate, and sodium hydrogen carbonate. Thereby, the content of alkali hydroxide in the liquid composition can be reduced and the handleability can be improved.

[0018] The liquid composition includes an alkali hydroxide including at least one selected from the group consisting of sodium hydroxide and potassium hydroxide, and water. The liquid composition may contain components other than these. A water reducing agent (Ad) and an antifoaming agent (DF) are included in at least one of the solid composition and the liquid composition.

[0019] The geopolimer composition according to one embodiment is obtained by blending the solid composition and the liquid composition of the kit for preparing the geopolimer composition. The manufacturing method of the geopolimer composition according to one embodiment includes a first preparation step of preparing the above-mentioned solid composition, a second preparation step of preparing the above-mentioned liquid composition, and a blending step of blending the solid composition prepared in the first preparation step and the liquid composition prepared in the second preparation step to obtain a geopolimer composition. The content described below is commonly applied to each embodiment of the kit for preparing the geopolimer composition, the geopolimer composition, and the manufacturing method of the geopolimer composition.

[0020] The liquid composition contains an alkali hydroxide containing at least one selected from the group consisting of sodium hydroxide and potassium hydroxide as an alkali source. The content of the alkali hydroxide in the liquid composition is preferably 5% by mass or less. Such a liquid composition is excellent in handleability because it does not fall under the category of poisons and highly toxic substances under the Poisonous and Deleterious Substances Control Law. When the content of the alkali hydroxide is low, it has been difficult to achieve both good fresh properties and excellent strength development in conventional geopolimer compositions. However, in this embodiment, since a specific retarder is used, these properties can be sufficiently improved. From the viewpoint of further improving the handleability, the content of the alkali hydroxide in the liquid composition is more preferably less than 5% by mass, and even more preferably 4.9% by mass or less. From the viewpoint of obtaining a geopolimer cured body having a sufficiently high compressive strength, the content of the alkali hydroxide in the liquid composition is preferably 2% by mass or more, more preferably 3% by mass or more, and even more preferably 4% by mass or more.

[0021] The liquid composition contains water. All the water contained in the geopolimer composition may be derived from the liquid composition, or water may be blended when blending the solid composition and the liquid composition to prepare the geopolimer composition. The following unit water amount is obtained as the total value of these. The unit water amount in the geopolimer composition is preferably 170 - 240 kg / m 3 , more preferably 190 - 230 kg / m 3 , even more preferably 200 - 220 kg / m3 、 particularly preferably 210 to 220 kg / m 3 . By setting the unit water amount within such a range, it is possible to achieve both a sufficiently high level of the fresh properties of the geopolimer composition and the compressive strength of the geopolimer hardened body at 28 days of age.

[0022] When the geopolimer composition (solid composition) contains an alkali carbonate, the total molar ratio (A / W) of the alkali metal (element) contained in the alkali hydroxide and the alkali carbonate to water in the geopolimer composition is preferably 0.01 or more and less than 0.20, more preferably 0.02 to 0.10, and even more preferably 0.03 to 0.08. As a result, it is possible to achieve both excellent strength development and good fresh properties at a sufficiently high level. The blending amount (in terms of solid content) of the alkali hydroxide is, for example, 5 to 20 kg / m 3 with respect to 1 m of the geopolimer composition, and may be, for example, 8 to 15 kg / m 3 . An aqueous alkali solution containing such an amount of alkali hydroxide may be used. As a result, it is possible to sufficiently improve the safety while maintaining excellent strength development and good fresh properties at a sufficiently high level. 3

[0023] The liquid composition preferably does not contain sodium silicate (Na 2 SiO 3 , Na 4 SiO 4 , Na 2 Si 2 O 5 , Na 2 Si 4 O 9 , etc.), potassium silicate (K 2 SiO 3 , etc.), and water glass. As a result, when the liquid composition and the solid composition are blended (blending step), the respective components are mixed, and silica fume (SF), or silica fume (SF) and an inorganic filler (F) dissolve in the alkali hydroxide, or an aqueous alkali solution containing an alkali hydroxide and an alkali carbonate. SiO contained in raw materials other than silica fume (SF) and inorganic filler (F)2 It may also be dissolved in an aqueous alkali solution, and components other than SiO 2 may also be dissolved in the aqueous alkali solution. In this way, an aqueous alkali silicate solution containing at least one selected from the group consisting of sodium and potassium as alkali metals is produced. In such a production method, the reaction between silica fume (SF) and inorganic filler (F) generated in the compounding step and the alkali hydroxide and alkali carbonate proceeds smoothly without being inhibited. In this way, a geopolimer composition excellent in strength development property and a geopolimer cured body having a sufficiently high compressive strength can be obtained.

[0024] The alkali carbonate that may be contained in the geopolimer composition (solid composition) contains at least one selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydrogen carbonate, and sodium hydrogen carbonate. By acting as an alkali stimulant, the alkali carbonate can improve the strength development property.

[0025] The blending amount (in terms of solid content) of the alkali carbonate is, for example, 5 to 100 kg / m 3 with respect to 1 m of the geopolimer composition. 3 This blending amount may be 10 kg / m 3 or more, or 15 kg / m 3 or more from the viewpoint of further improving safety and strength development property. Within such a range, the alkali carbonate acts more effectively as an alkali stimulant. This blending amount may be 80 kg / m 3 or less, 50 kg / m 3 or less, or 20 kg / m 3 or less from the viewpoint of improving the fresh properties of the geopolimer composition.

[0026] The ratio of the alkali metal (element) contained in the alkali carbonate to the total alkali metal (element) contained in the alkali hydroxide and the alkali carbonate may be 20 to 90%. Thereby, it is possible to achieve both a fresh property of the geopolimer composition and a sufficient high level of the compressive strength of the geopolimer cured body at 28 days of age. The ratio is more preferably 80% or less, still more preferably 70% or less, and particularly preferably 60% or less. Thereby, an increase in viscosity associated with the generation of fine CaCO 3 is suppressed, and the fresh property of the geopolimer composition can be further improved. The ratio may be more preferably 30% or more, still more preferably 40% or more, and particularly preferably 50% or more. Thereby, while further enhancing the safety in producing the geopolimer composition, the alkali carbonate acts more effectively as an alkali stimulant, and the compressive strength of the geopolimer cured body at 28 days of age can be further increased. Examples of the alkali metal (element) include sodium and potassium.

[0027] As the silica fume (SF), a general one used in a cement composition can be used. The BET specific surface area of the silica fume (SF) may be 10 m 2 / g or more, may be 14 m 2 / g or more, and may be 16 m 2 / g or more. Since the silica fume having a large BET specific surface area has high reactivity, it can be dissolved early in the alkaline aqueous solution and supply SiO 2 smoothly. The upper limit of the BET specific surface area of the silica fume (SF) may be 20 m 2 / g or less from the viewpoint of easy availability. The blending amount of the silica fume (SF) in the geopolimer composition is, for example, 10 to 100 kg / m 3 with respect to 1 m 3 of the geopolimer composition, 20 to 80 kg / m 3 , or 30 to 70 kg / m 3 and may be.

[0028] The inorganic filler (F) includes fly ash (FA) and blast furnace slag fine powder (BS). The inorganic filler (F) may contain inorganic components other than fly ash (FA) and blast furnace slag fine powder (BS). Examples of such inorganic components include fillers having at least one selected from the group consisting of Si, Al, and Ca as constituent elements, such as wood biomass ash, municipal solid waste incineration ash, calcium carbonate, metakaolin, sewage sludge, and volcanic ash.

[0029] The content of the blast furnace slag fine powder (BS) in the inorganic filler (F) is 10% by volume or more, preferably 20% by volume or more, more preferably 25% by volume or more, and still more preferably 30% by volume or more. Thereby, good fresh properties and excellent strength development properties can be achieved at a sufficiently high level. The content of the blast furnace slag fine powder (BS) in the inorganic filler (F) is 90% by volume or less, preferably 80% by volume or less, more preferably 75% by volume or less, and still more preferably 70% by volume or less. Thereby, good fresh properties and excellent strength development properties can be achieved at a sufficiently high level.

[0030] The ratio of the blast furnace slag fine powder (BS) to the total of the fly ash (FA) and the blast furnace slag fine powder (BS) is preferably 10 to 90% by volume. The ratio of the blast furnace slag fine powder (BS) to the total of the fly ash (FA) and the blast furnace slag fine powder (BS) is more preferably 30% by volume or more, still more preferably 50% by volume or more, and particularly preferably 60% by volume or more. Thereby, the fresh properties of the geopolimer composition and the compressive strength of the geopolimer cured product can be further balanced at a sufficiently high level. The ratio of the blast furnace slag fine powder (BS) to the total of the fly ash (FA) and the blast furnace slag fine powder (BS) is more preferably 85% by volume or less, still more preferably 80% by volume or less, and particularly preferably 75% by volume or less. Thereby, the fresh properties of the geopolimer composition and the compressive strength of the geopolimer cured product can be further balanced at a sufficiently high level.

[0031] Fly ash (FA) is preferably type II among types I to IV specified in JIS A6201:2015. Type II fly ash has higher reactivity than types III and IV, and thus is excellent in strength development. Although type I fly ash has high reactivity because its specific surface area is larger than that of type II, it has an increasing viscosity, a high price, and a small circulation volume, so it tends to be difficult to obtain. The Blaine specific surface area of blast furnace slag fine powder (BS) is preferably 3500~6000 cm 2 / g, more preferably 4000~5000 cm 2 / g. Although the higher the Blaine specific surface area of blast furnace slag fine powder, the higher the reactivity and the better the strength development, it tends to have high viscosity and a short pot life.

[0032] The total ratio of fly ash (FA) and blast furnace slag fine powder (BS) to the entire inorganic filler (F) is, for example, 60% by volume or more, preferably 70% by volume or more, more preferably 80% by volume or more, still more preferably 90% by volume or more, and particularly preferably 95% by volume or more. The inorganic filler (F) may consist only of fly ash (FA) and blast furnace slag fine powder (BS).

[0033] The blending amount of the inorganic filler (F) is, for example, 450~600 kg / m 3 with respect to 1 m 3 of the geopolimer composition, and may be 465~590 kg / m 3 or may be 470~580 kg / m 3 .

[0034] The retarder (Re), also referred to as a setting retarder, has the effect of delaying the setting timing of the geopolimer composition. The retarder (Re) contains an alkali metal salt of gluconic acid and an alkali metal salt of citric acid. When preparing the geopolimer composition by reducing the usage amount of alkali hydroxide, these components delay the setting while improving the fresh properties of the geopolimer composition, and can sufficiently increase the compressive strength at 28 days of age of the geopolimer hardened body to improve the subsequent strength development.

[0035] Examples of the alkali metal gluconate include sodium gluconate and potassium gluconate. From the viewpoint of further improving the fresh properties, the alkali metal gluconate preferably contains sodium gluconate.

[0036] Examples of the alkali metal citrate include potassium dihydrogen citrate, sodium dihydrogen citrate, dipotassium hydrogen citrate, disodium hydrogen citrate, tripotassium citrate, and trisodium citrate. These may be hydrates. From the viewpoint of further improving the strength development property, the alkali metal citrate preferably contains at least one selected from the group consisting of sodium dihydrogen citrate, disodium hydrogen citrate, and trisodium citrate, and more preferably contains trisodium citrate.

[0037] Since the delay performance of the alkali metal gluconate is higher than that of the alkali metal citrate, the alkali metal gluconate can improve the fresh properties of the diopolymer composition. On the other hand, the alkali metal citrate exhibits a unique property that it can improve the strength development property while improving the fresh properties of the diopolymer composition. Thus, by using the alkali metal gluconate and the alkali metal citrate in a well-balanced combination, excellent strength development property can be exhibited while having good fresh properties.

[0038] The total content of the alkali metal gluconate and the alkali metal citrate in the kit for preparing the geopolimer composition and the inorganic filler (F) in the geopolimer composition is preferably 0.05 to 5% by mass. Thereby, it is possible to achieve both a fresh property of the geopolimer composition and a high level of compressive strength of the geopolimer cured body at 28 days of age. From the viewpoint of achieving both the fresh property of the geopolimer composition and the compressive strength of the geopolimer cured body at an even higher level, the above total content of the alkali metal gluconate and the alkali metal citrate is more preferably 0.1 to 4% by mass, still more preferably 0.3 to 3% by mass, and particularly preferably 0.5 to 2% by mass. The kit for preparing the geopolimer composition and the geopolimer composition may not contain a retarder (Re) other than the alkali metal gluconate and the alkali metal citrate.

[0039] The content of the alkali metal gluconate relative to the total amount of the inorganic filler (F) is preferably 0.01 to 2% by mass, more preferably 0.03 to 1.5% by mass, and still more preferably 0.05 to 1.0% by mass. Thereby, it is possible to achieve a good balance between the fresh property and the excellent strength development property. From the same viewpoint, the content of the alkali metal citrate relative to the total amount of the inorganic filler (F) in the kit for preparing the geopolimer composition and the geopolimer composition is preferably 0.05 to 4.0% by mass, more preferably 0.1 to 3.0% by mass, and still more preferably 0.3 to 2.0% by mass. The mass ratio of the alkali metal citrate to the alkali metal gluconate is 1 to 20.

[0040] In order to be able to flexibly adjust the fresh properties and strength development properties of the geopololymer composition according to the application, the content of the alkali metal gluconate and the content of the alkali metal citrate may be different. In order to easily achieve a good balance between good fresh properties and excellent strength development properties, the mass ratio of the alkali metal citrate to the alkali metal gluconate may be 1 to 20. From the perspective of further improving the fresh properties, the mass ratio may be 1.5 or more, or 1.8 or more. From the perspective of further improving the strength development properties, the mass ratio may be 18 or less, or 15 or less.

[0041] The kit for preparing the geopololymer composition and the geopololymer composition may or may not contain a retarder other than the alkali metal gluconate and the alkali metal citrate. The ratio of the alkali metal gluconate and the alkali metal citrate to the total retarder may be 70% by mass or more, 80% by mass or more, or 90% by mass or more. Thereby, the process of material design can be made more efficient.

[0042] The solid composition may contain fine aggregate (S). The fine aggregate (S) may include at least one selected from natural aggregates such as river sand, mountain sand, land sand, and sea sand, crushed sand, silica sand, blast furnace slag fine aggregate, ferronickel slag fine aggregate, and electric furnace oxidized slag fine aggregate, and recycled fine aggregate. As the fine aggregate, these may be used alone or in combination of a plurality. The oven-dry density of the fine aggregate (S) may be 2.2 to 2.9 g / cm 3 and may be 2.4 to 2.8 g / cm 3 and may be 2.5 to 2.7 g / cm 3 either. The blending amount of the fine aggregate is, for example, 1000 to 1600 kg / m 3 per 1 m 3 of the geopololymer composition and may be 1200 to 1550 kg / m 3 and may be 1300 to 1500 kg / m 3 either.

[0043] The geopolymer composition contains a water reducing agent (Ad) and an antifoaming agent (DF). The water reducing agent (Ad) and the antifoaming agent (DF) are included in at least one of the solid composition and the liquid composition in the kit for preparing the geopolymer composition, and preferably in the solid composition. Thereby, the storage stability can be further improved. The water reducing agent (Ad) may include at least one selected from the group consisting of lignin derivatives, hydroxy-based composites, naphthalene sulfonic acid-based compounds, aminosulfonic acid-based compounds, and polycarboxylic acid-based compounds. The lignin derivative in this specification is a compound derived from lignin, and examples thereof include lignin sulfonate. The water reducing agent (Ad) may include at least one selected from the group consisting of water reducing agents, AE water reducing agents, high-performance water reducing agents, and high-performance AE water reducing agents.

[0044] In the geopolymer composition, the content of the water reducing agent (Ad) relative to the total amount of the inorganic filler (F) may be 0.1 to 1.5% by mass. Such a geopolymer composition can achieve a sufficient level of both fresh properties and strength development. From the viewpoint of achieving a higher level of both fresh properties and strength development, the content of the water reducing agent (Ad) relative to the total amount of the inorganic filler (F) is preferably 0.2 to 1.0% by mass, more preferably 0.3 to 0.6% by mass.

[0045] As the antifoaming agent (DF), those used in cement compositions can be used, and examples thereof include nonionic surfactant types, oil types, and emulsion types.

[0046] In the geopolymer composition, the content of the antifoaming agent (DF) relative to the total amount of the inorganic filler (F) is preferably 0.002 to 0.10% by mass, more preferably 0.005 to 0.05% by mass, and even more preferably 0.008 to 0.03% by mass. When the geopolymer composition contains the water reducing agent (Ad), the compressive strength may decrease when the bubbles are generated and cured. Therefore, by containing the antifoaming agent (DF) at the above ratio, the compressive strength of the geopolymer cured body can be made sufficiently high while maintaining the production cost of the geopolymer composition.

[0047] The solid composition and the liquid composition may each be prepared by mixing the respective materials simultaneously or sequentially, or after preparing a plurality of blends by blending some of the materials with each other, the plurality of blends may be mixed and prepared. When preparing a geopolimer composition by blending the solid composition and the liquid composition, another material may be further blended. That is, in the blending step, the said another material may be blended. Examples of such materials include water, fine aggregate, expansive agent, shrinkage reducing agent, rust inhibitor, and waterproof material. These materials may be included in the solid composition or the liquid composition.

[0048] In the geopolimer composition, the total volume ratio (L / F) of alkali carbonate, alkali hydroxide, fumed silica (SF) and water to the total inorganic filler (F) is preferably 0.6 to 1.6, more preferably 0.7 to 1.5, still more preferably 0.8 to 1.4, and particularly preferably 0.9 to 1.3. By being in such a range, it is possible to achieve both a sufficiently high level of the fresh properties of the geopolimer composition and the compressive strength of the cured geopolimer.

[0049] There are no particular restrictions on the stirring devices used in the first preparation step and the second preparation step for preparing the solid composition and the liquid composition respectively, and the blending step. In the second preparation step, since the liquid composition is prepared, it may be prepared using a normal container. In the first preparation step and the blending step, for example, a mortar mixer, a twin-shaft forced kneading mixer, a pan-type mixer, a grout mixer or a hand mixer can be used. In this way, a geopolimer composition having sufficiently good fresh properties and also sufficiently excellent strength development can be produced.

[0050] The geopolimer composition obtained by blending a solid composition and a liquid composition contains an inorganic filler (F), an alkaline silicate aqueous solution containing at least one selected from the group consisting of sodium and potassium, a retarder (Re), a water reducer (Ad), an antifoaming agent (DF), and an alkaline carbonate containing at least one selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydrogen carbonate, and sodium hydrogen carbonate. At least a part of the inorganic filler (F) may be dissolved in the alkaline silicate aqueous solution. Materials other than the inorganic filler (F) may be dissolved in the alkaline silicate aqueous solution. The geopolimer composition may include fine aggregate, expansive agent, shrinkage reducing agent, rust inhibitor, waterproofing material, and the like.

[0051] The 15-beat flow (15-beat mortar flow) of the geopolimer composition is preferably 140 to 220 mm, more preferably 155 to 210 mm. Such a geopolimer composition has excellent fluidity and workability. The 15-beat flow is measured by the method described in the examples. The pot life of the geopolimer composition is preferably 90 minutes or more, more preferably 120 minutes or more. Such a geopolimer composition has excellent fresh properties and workability. The pot life is measured by the method described in the examples.

[0052] The geopolimer composition has excellent strength development properties. The compressive strength of the geopolimer hardened body when cured in a thermo-hygrostat at a temperature of 20 ± 2°C and a relative humidity of 60 ± 5% for 28 days is preferably 55 N / mm 2 or more, more preferably 60 N / mm 2 or more, and even more preferably 63 N / mm 2 or more.

[0053] The geopolimer composition having good fresh shape and excellent strength development properties preferably satisfies (1), more preferably (2), even more preferably (3), and particularly preferably (4). (1) The 15-beat flow is 150 mm or more, and the compressive strength at 28 days of age is 61 N / mm 2 or more (2) The 15-beat flow is 155 mm or more, and the compressive strength at 28 days of age is 64 N / mm 2 or more (3) The 15-beat flow is 160 mm or more, and the compressive strength at 28 days of age is 65 N / mm 2 or more (4) The 15-beat flow is 170 mm or more, and the compressive strength at 28 days of age is 66 N / mm 2 or more

[0054] The geopolimer cured body according to one embodiment can be obtained by curing the above-described geopolimer composition. This geopolimer cured body is excellent in safety during production and has a high compressive strength. The compressive strength of the geopolimer cured body at 28 days of age when subjected to sealed curing is as described above.

[0055] The method for producing a geopolimer cured body according to one embodiment has a curing step of curing the above-described geopolimer composition. The geopolimer cured body thus obtained is excellent in safety during production and has a high compressive strength.

[0056] As uses of the geopolimer cured body, in addition to on-site construction, for example, secondary products can be mentioned. When producing a geopolimer cured body by curing a geopolimer composition, for example, it may be subjected to sealed curing or steam curing. That is, the curing step may be performed by sealed curing or steam curing. The compressive strength of the geopolimer cured body at 28 days of age when subjected to sealed curing is as described above.

[0057] Although several embodiments have been described above, the present disclosure is not limited to the above embodiments at all. For example, the present disclosure includes the following contents.

[0058] [1] A kit for preparing a geopolimer composition having a first package containing a solid composition and a second package containing a liquid composition, The solid composition is, It contains silica fume (SF), an inorganic filler (F) including fly ash and fine powder of blast furnace slag, and a retarder (Re). The liquid composition contains an alkali hydroxide selected from the group consisting of sodium hydroxide and potassium hydroxide, and water. A water reducing agent (Ad) and an antifoaming agent (DF) are included in at least one of the solid composition and the liquid composition. A kit for preparing a diopolymer composition, wherein the retarder (Re) contains an alkali metal gluconate and an alkali metal citrate. [2] The kit for preparing a diopolymer composition according to [1], wherein the total content of the alkali metal gluconate and the alkali metal citrate with respect to the inorganic filler (F) is 0.05 to 5% by mass. [3] The kit for preparing a diopolymer composition according to [1] or [2], wherein the mass ratio of the alkali metal citrate to the alkali metal gluconate is 1 to 20. [4] The content of the alkali hydroxide in the liquid composition is 5% by mass or less. The solid composition contains an alkali carbonate containing at least one selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydrogen carbonate, and sodium hydrogen carbonate. The kit for preparing a diopolymer composition according to any one of [1] to [3]. [5] A diopolymer composition obtained by blending the solid composition and the liquid composition in the kit for preparing a diopolymer composition according to at least any one of [1] to [3]. [6] A diopolymer cured body obtained by curing a blend of the solid composition and the liquid composition in the kit for preparing a diopolymer composition according to at least any one of [1] to [3]. [7] A first preparation step of preparing a solid composition containing silica fume (SF), an inorganic filler (F) including fly ash and fine powder of blast furnace slag, and a retarder (Re). A second preparation step of preparing a liquid composition containing at least one selected from the group consisting of sodium hydroxide and potassium hydroxide and water; A compounding step of compounding at least the solid composition and the liquid composition to obtain a diopolymer composition; A water reducing agent (Ad) and an antifoaming agent (DF) are contained in at least one of the solid composition and the liquid composition; A method for producing a diopolymer composition, wherein the retarder (Re) contains an alkali metal gluconate and an alkali metal citrate. [8] The total content of the alkali metal gluconate and the alkali metal citrate with respect to the inorganic filler (F) is 0.05 to 5% by mass, and the method for producing a diopolymer composition according to [7]. [9] The content of the alkali hydroxide in the liquid composition is 5% by mass or less; The solid composition contains an alkali carbonate containing at least one selected from the group consisting of potassium carbonate, sodium carbonate, potassium hydrogen carbonate, and sodium hydrogen carbonate, and the method for producing a diopolymer composition according to [7] or [8].

[10] A method for producing a diopolymer cured body, which has a curing step of curing the diopolymer composition produced by the production method according to any one of [7] to [9] above.

Example

[0059] The content of the present disclosure will be described in more detail with reference to Examples and Comparative Examples, but the present disclosure is not limited to the following Examples.

[0060] (Comparative Examples 1 to 7) <Preparation of Diopolymer Composition> As raw materials for the diopolymer composition, the materials shown in Table 1 below were used. Also, the chemical components of silica fume (SF), fly ash type II (FA), and blast furnace slag fine powder (BS) were as shown in Table 2.

[0061]

Table 1

[0062] [Table 2]

[0063] A geopolimer composition was prepared using the materials shown in Table 1. Specifically, a liquid composition was prepared by mixing liquid raw materials, and a solid composition was prepared by mixing solid raw materials. The liquid composition and the solid composition were mixed using a mortar mixer to prepare a geopolimer composition. The liquid composition was prepared by blending an aqueous sodium hydroxide solution (SH), water (w), an AE water reducer (Ad), and an antifoaming agent (DF).

[0064] The solid composition was prepared by putting sodium carbonate (SC), fumed silica (SF), fly ash type II (FA), blast furnace slag fine powder (BS), sea sand (S1), crushed sand (S2), and a retarder (any one of Re1 to Re6) into a mortar mixer and dry mixing for 30 seconds. Then, the above-mentioned liquid composition was added to this mortar mixer and kneaded for 90 seconds. After scraping down, it was kneaded again for 90 seconds. In this way, the geopolimer compositions of each comparative example were prepared.

[0065] The unit amount of each material per 1 m of the geopolimer composition prepared in each comparative example 3 was made as shown in Table 3. As shown in Table 3, a geopolimer composition not containing a retarder (Re) was used as a reference sample (Comparative Example 1), and the geopolimer compositions of each comparative example were prepared. The types of retarders used in the preparation of each geopolimer composition, and the ratios or proportions of each component and each material are summarized in Table 4.

[0066]

Table 3

[0067] In Tables 3 and 4, the symbol "L" represents the total of sodium carbonate (SC), aqueous sodium hydroxide solution (SH), water (w), and silica fume (SF), and the symbol "F" represents the total of Class II fly ash (FA) and blast furnace slag fine powder (BS) (total of inorganic fillers). Each symbol is also shown in Table 1.

[0068]

Table 4

[0069] In Table 4, "A / W" represents the molar ratio of alkali metal to water contained in the geopololymer composition. The water contained in the geopololymer composition is the total of the water contained in the aqueous sodium hydroxide solution (SH) and tap water (w). In Table 4, "Si / A" represents the molar ratio of silicon dioxide (SiO 2 ) to the alkali metal contained in L, and "unit water amount" is the unit amount of the total of the water contained in the aqueous sodium hydroxide solution (SH) and water (w). "Alkali composition ratio" is the molar percentage of the alkali metal (Na) contained in sodium carbonate (SC) and the alkali metal (Na) derived from the aqueous sodium hydroxide solution (SH) when the total amount of alkali metal contained in the alkali source (SC + SH) is taken as the reference (100 mol%). In Table 4, "NaOH concentration" is the content of NaOH in the liquid composition. In Table 4, "Re / F" is the content of retarder (Re) with respect to the total inorganic filler (F). In Table 4, "Ad / F" is the content of water reducer (Ad) with respect to the total inorganic filler (F). In Table 4, "DF / F" is the content of defoamer (DF) with respect to the total inorganic filler (F).

[0070] <Evaluation of Geopolymer Composition> To confirm the fresh properties of the geopololymer compositions of each comparative example, a 15-beat flow test of the geopololymer compositions was conducted. The 15-beat flow test was carried out in accordance with JIS R 5201:2015 "Physical Test Methods for Cement". The ratio of the 15-beat flow of each comparative example was calculated with respect to Comparative Example 1 without using a retarder as the reference (100%). These calculated results were as shown in the column of "15-beat flow ratio to reference" in Table 5.

[0071] The pot life of the geopolymers of each comparative example was evaluated. A durometer (total length: 23 cm, penetration part: conical shape) was used to measure the pot life. The geopolymers of each comparative example were placed in a cylindrical container with a diameter of 18.5 cm and a height of 10 cm, and the durometer was inserted every 5 minutes to measure the penetration resistance value. The penetration resistance value at which driving and forming are possible was set to 1.0 N / mm 2 and the time not exceeding this value was defined as the pot life. The measurement results were as shown in Table 5.

[0072] To evaluate the strength development of the geopolymers of each comparative example, the compressive strength of the geopolymer cured body obtained by curing the geopolymer was measured. The geopolymers of each comparative example were poured into a predetermined mold and subjected to sealed curing. The sealed curing was carried out in a thermo-hygrostat chamber at a temperature of 20 ± 2°C and a relative humidity of 60 ± 5% until the age of 28 days. Using the cylindrical test specimens (diameter 5 cm × height 10 cm) thus obtained, the compressive strength at the age of 28 days was measured. The measurement results were as shown in Table 5.

[0073]

Table 5

[0074] In Table 5, the ratios of the 15-beat flow and compressive strength of the geopolymers of each comparative example were calculated with Comparative Example 1 without using a retarder as the reference (100%). These calculated results were as shown in the column of "Ratio to the reference" in Table 5. Among Comparative Examples 2 to 7, the geopolymer of Comparative Example 2 containing an alkali metal gluconate as a retarder had the highest values of 15-beat flow and compressive strength. The geopolymer of Comparative Example 3 containing an alkali metal citrate and the geopolymer of Comparative Example 4 containing an alkali metal phosphate showed relatively high strength development. From these results, the formulations of the retarders (Re1, Re2, Re3) used in Comparative Examples 2 to 4 were changed to study the fresh properties and strength development.

[0075] [Effect of the Content and Combination of Retarders] (Example 1, Comparative Examples 3-1, 4-1, 4-2) A geopolimer composition was prepared and evaluated in the same manner as in Comparative Examples 2 to 4, except that the content of the retarders (Re1, Re2, Re3) with respect to the total amount of the inorganic filler (F) was changed as shown in Table 6. The evaluation results were as shown in Table 6. For comparison, the values of Comparative Example 1, Comparative Example 3, and Comparative Example 4 shown in Tables 3 and 4 were also included in Table 6.

[0076]

Table 6

[0077] As shown in Table 6, in Example 1 where an alkali metal gluconate and an alkali metal citrate were used in combination, the value of the 15-beat flow was higher than that of any of the comparative examples. Although Comparative Example 3-1 had a high compressive strength, the value of the 15-beat flow was low. The geopolimer composition of Example 1 had both good fresh properties and excellent strength development.

[0078] [Effect of the Content of Retarders] (Examples 2 to 5) Geopolimer compositions of Examples 2 to 5 were prepared and evaluated in the same manner as in Example 1, except that the content of the retarders (Re1, Re2) with respect to the total amount of the inorganic filler (F) was changed as shown in Table 6. The evaluation results were as shown in Table 7. Table 7 also showed the mass ratio (Re2 / Re1) of the alkali metal citrate to the alkali metal gluconate.

[0079] [Effect of Unit Water Amount] (Example 6) A geopolimer composition of Example 6 was prepared and evaluated in the same manner as in Example 3, except that the unit amount of each material was changed as shown in Table 8. The evaluation results were as shown in Table 7. For comparison, the unit amounts of Examples 1 to 5 were also included in Table 8. Table 9 showed the components and the ratios or proportions of the materials of each example in summary.

[0080]

Table 7

[0081]

Table 8

[0082]

Table 9

[0083] As shown in Table 7, in each example, the 15-beat flow of the geopolimer composition was 150 mm or more, and the compressive strength of the geopolimer cured body was 64 N / mm 2 or more. From this, it was confirmed that the geopolimer composition of each example has both good fresh properties and excellent strength development properties.

[0084] As shown in Table 9, the NaOH concentration of the liquid composition used in each example was 4.8% by mass and did not fall under the category of poisons and highly toxic substances under the Poisonous and Deleterious Substances Control Law. As shown in Table 9, the unit water amount of the geopolimer composition of Example 6 was larger than that of the other examples. As shown in Table 7, Example 6 and Example 3 had the same content of retarder with respect to the inorganic filler. From this result, it was confirmed that by setting the unit water amount of the geopolimer composition to be from 206 kg / m 3 to 220 kg / m 3 , it is possible to increase the value of the 15-beat flow while maintaining the compressive strength almost constant.

Industrial Applicability

[0085] According to the present disclosure, there is provided a geopolimer composition having both good fresh properties and excellent strength development properties. Further, there are provided a method for producing a geopolimer composition capable of easily producing such a geopolimer composition and a kit for preparing a geopolimer composition. Further, by using such a geopolimer composition, there are provided a geopolimer cured body having high compressive strength and a method for producing the same.

Claims

1. A kit for preparing a geopolymer composition, comprising a first package containing a solid composition and a second package containing a liquid composition, The solid composition comprises: The composition comprises silica fume (SF), an inorganic filler (F) containing fly ash and ground granulated blast furnace slag, and a retarder (Re), The liquid composition comprises: An alkali hydroxide including at least one selected from the group consisting of sodium hydroxide and potassium hydroxide, and water, A water reducing agent (Ad) and a defoamer (DF) are contained in at least one of the solid composition and the liquid composition, A kit for preparing a geopolymer composition, wherein the retarder (Re) contains an alkali metal gluconate and an alkali metal citrate.

2. The kit for preparing a geopolymer composition according to claim 1, wherein the total content of the alkali metal gluconate and the alkali metal citrate relative to the inorganic filler (F) is 0.05 to 5% by mass.

3. The kit for preparing a geopolymer composition according to claim 1 or 2, wherein the mass ratio of the alkali metal citrate to the alkali metal gluconate is 1 to 20.

4. The content of the alkali hydroxide in the liquid composition is 5% by mass or less, The solid composition comprises at least one alkali carbonate selected from the group consisting of potassium carbonate, sodium carbonate, potassium bicarbonate and sodium bicarbonate. Kit for preparing a geopolymer composition according to claim 1 or 2.

5. A geopolymer composition obtained by mixing the solid composition and the liquid composition in the geopolymer composition preparation kit according to at least claim 1 or 2.

6. A geopolymer hardened body obtained by hardening a blend of the solid composition and the liquid composition in the geopolymer composition preparation kit according to at least claim 1 or 2.

7. A first preparation step of preparing a solid composition containing silica fume (SF), an inorganic filler (F) containing fly ash and ground granulated blast furnace slag, and a retarder (Re); A second preparation step of preparing a liquid composition containing an alkali hydroxide including at least one selected from the group consisting of sodium hydroxide and potassium hydroxide, and water; A blending step of blending at least the solid composition and the liquid composition to obtain a geopolymer composition; A water reducing agent (Ad) and a defoamer (DF) are contained in at least one of the solid composition and the liquid composition, A method for producing a geopolymer composition, wherein the retarder (Re) contains an alkali metal gluconate and an alkali metal citrate.

8. The method for producing a geopolymer composition according to claim 7, wherein the total content of the alkali metal gluconate and the alkali metal citrate relative to the inorganic filler (F) is 0.05 to 5% by mass.

9. The content of the alkali hydroxide in the liquid composition is 5% by mass or less, The method for producing a geopolymer composition according to claim 7 or 8, wherein the solid composition comprises an alkali carbonate containing at least one selected from the group consisting of potassium carbonate, sodium carbonate, potassium bicarbonate and sodium bicarbonate.

10. A method for producing a geopolymer hardened body, comprising a hardening step of hardening the geopolymer composition produced by the manufacturing method according to claim 7 or 8.

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