Mixture, alkali activated material composition, alkali activated material cured product, method for producing the same, precast product obtained from alkali activated material composition, and method for producing the same

Abstract

To provide an alkali active material composition excellent in fluidity and a mixture giving the alkali active material composition.SOLUTION: A mixture containing 5 pts.mass or more and 25 pts.mass or less of an alkali source and 0.1 pts.mass or more and 6.25 pts.mass or less of at least one of aluminum sulfate or aluminum phosphate based on 100 pts.mass of an active filler, an alkali active material composition containing 5 pts.mass or more and 25 pts.mass or less of an alkali source and 0.1 pts.mass or more and 6.25 pts.mass or less of at least one of aluminum sulfate or aluminum phosphate based on 100 pts.mass of the active filler, a fine aggregate, water and a coarse aggregate, and an alkali active material cured product obtained from the alkali active material composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a mixture used in an alkaline active material composition, an alkaline active material composition, and a cured alkaline active material obtained from the alkaline active material composition, and a method for producing the same. The present invention also relates to a precast product obtained from the alkali-activated material composition and a method for producing the same. [Background technology]

[0002] Precast products such as Hume pipes and box culverts have a compressive strength of 40N / mm due to their use. 2 from 90N / mm 2 High strength materials are required. To achieve such high strength, high strength precast products are typically formed using cement. The cement that is produced industrially on a large scale is Portland cement (JIS A 5210), whose main raw material is limestone. Limestone is primarily composed of calcium carbonate (CaCO3), which decomposes into calcium oxide (CaO) at approximately 900°C when fired, simultaneously emitting CO2. Therefore, when precast products are manufactured using such Portland cement, CO2 is emitted during the cement burning process.

[0003] On the other hand, in recent years, there has been a demand to reduce CO2 emissions from the perspective of global environmental issues. In order to reduce CO2 emissions, methods of producing precast products without using cement are attracting attention, and methods of producing precast products using an alkaline activated material method, which uses an alkaline activated material composition as an alternative raw material to cement, are being investigated.

[0004] Alkali-activated material compositions generally contain a filler containing aluminum and silicon, and an alkali source that activates and hardens the filler (see, for example, Patent Document 1). Since each of the materials constituting such an alkaline active material composition emits little CO2, it is believed that the use of the alkaline active material composition has the effect of reducing CO2 emissions. As fillers used in the alkali activated material composition, industrial by-products such as blast furnace slag, fly ash, and sewage incineration sludge are mainly used. The use of such industrial by-products is expected to contribute to resource conservation through the reuse of waste materials. Blast furnace slag is used both with and without gypsum. Since the quality of such industrial by-products is unstable, alkali-activated material compositions obtained using them may have unstable workability and the quality of the cured product, such as mechanical strength.

[0005] Attempts have been made to stabilize the mechanical strength of precast products produced by an alkali-activated material method using an alkali-activated material composition made from industrial by-products. For example, in Patent Document 2, the types and ratios of fillers and aqueous alkali activator solutions are investigated in an attempt to improve the compressive strength of the resulting precast concrete and stabilize workability.

[0006] However, although Patent Document 2 reports the compressive strength of the precast product, there is a demand for further improvement in strength for precast products that require high strength.

[0007] Furthermore, Patent Document 3 considers a hardened alkali-activated material and a manufacturing method thereof, and proposes a manufacturing method for a hardened alkali-activated material, which includes a step of kneading raw materials that do not contain a sodium silicate aqueous solution and that contain inorganic powder, sodium hydroxide, water, and aggregate to obtain a kneaded mixture, and a step of pre-curing the kneaded mixture and then steam curing it, the inorganic powder including fly ash, ground blast furnace slag, and silica fume, and the pre-curing is carried out at a temperature of 10°C to 50°C, which is lower than the temperature used for the steam curing, for 6 hours or more. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2008-239446 [Patent Document 2] Patent Publication No. 2023-145830 [Patent Document 3] Patent No. 6746302 Summary of the Invention [Problem to be solved by the invention]

[0009] As mentioned above, there are high expectations for alkali-activated material compositions from the viewpoint of environmental issues, etc. However, because they use industrial by-products, there is a need to stably produce precast products with mechanical properties such as strength, particularly high compressive strength. As a method for producing a precast product with high compressive strength using an alkali-activated material composition, various curing conditions for hardening the alkali-activated material composition during production, such as the curing time and temperature, have been investigated, as shown in Patent Document 3, for example. For example, one method for improving compressive strength has been investigated, which involves increasing the amount of alkali used. However, increasing the amount of alkali accelerates the hardening of the alkali-activated material composition, which can reduce the fluidity of the composition during hardening and make it difficult to handle. In other methods for improving compressive strength, it has been difficult to achieve both compressive strength and handling properties, such as fluidity.

[0010] Therefore, there is a need for the development of an alkali-activated material composition that is capable of stably producing precast products having mechanical properties such as strength, particularly high compressive strength, and that has excellent fluidity. An object of the present invention is to provide an alkaline active material composition having excellent fluidity and a mixture that provides said alkaline active material composition. [Means for solving the problem]

[0011] The present inventors have studied mixtures that can be used to form alkaline active material compositions having excellent fluidity and have found that a specific composition has excellent fluidity, thereby completing the present invention. That is, the present invention has the following aspects. [1] A mixture containing 5 to 25 parts by mass of an alkali source and 0.1 to 6.25 parts by mass of at least one of aluminum sulfate and aluminum phosphate per 100 parts by mass of an active filler. [2] The mixture according to [1], wherein the alkali source is at least one selected from the group consisting of sodium orthosilicate, sodium metasilicate, and an alkali solution. [3] The mixture according to [2], wherein the alkaline source is sodium orthosilicate. [4] The mixture according to any one of [1] to [3], wherein the active filler contains ground granulated blast furnace slag. [5] The mixture according to any one of [1] to [4], wherein the active filler further contains a compound having pozzolanic reactivity. [6] The mixture according to [5], wherein the compound having pozzolanic reactivity is at least one of fly ash and silica fume.

[0012] Furthermore, the present invention has the following aspects. [7] An alkali-activated material composition containing, relative to 100 parts by mass of an active filler, 5 parts by mass or more and 25 parts by mass or less of an alkali source, 0.1 parts by mass or more and 6.25 parts by mass or less of at least one of aluminum sulfate and aluminum phosphate, and further containing fine aggregate and water. [8] The alkali activated material composition according to [7] above, further containing coarse aggregate.

[0013] Furthermore, the present invention has the following aspects. [9] A method for producing a hardened alkali active material by kneading the alkali active material composition according to [7] or [8] above, and curing the composition including pre-curing and steam curing at an accumulated temperature of 250°C·hours or more.

[10] A cured product of an alkali-activated material obtained by the manufacturing method described in

[11] above.

[0014] The present invention also has the following aspects.

[12] A precast product obtained from the alkali activated material composition according to [7] or [8].

[13] A method for producing a precast product, comprising molding the alkaline active material composition according to [7] or [8] above by any one of centrifugal molding, vibration molding and pour molding. [Effects of the Invention]

[0015] According to the present invention, there are provided an alkaline active material composition having excellent fluidity and a mixture that provides the alkaline active material composition. The present invention also provides a method for producing a cured alkali-activated material obtained from the alkali-activated material composition, and a cured alkali-activated material obtained by the method. The present invention further provides a precast product obtained from the alkali-activated material composition and a method for producing the precast product. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 2 is a graph showing the relationship between the amount of alkali in the alkali activated material compositions obtained in the Reference Example and Examples 2 to 4 and the compressive strength. [Figure 2] 1 shows the change over time in the length change rate of the cured product of the alkali activated material composition A obtained in Reference Example. [Figure 3] 1 shows the change over time in the length change rate of the cured product of the alkali activated material composition I obtained in Example 6. [Figure 4]1 shows the change over time in the length change rate of the cured product of alkali activated material composition J obtained in Example 7. [Figure 5] This is a diagram of the equipment used to test the watertightness of joints as specified in the Sewerage Association Standard JSWAS A-6 Watertightness Test. [Figure 6] This is a diagram of an apparatus used to check the external pressure strength of precast products as specified in the Sewerage Association standard JSWAS A-6. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not to be construed as being limited to these descriptions. The mixture of the present invention (hereinafter also referred to as "this mixture") contains 5 to 25 parts by mass of an alkali source and 0.1 to 6.25 parts by mass of at least one of aluminum sulfate and aluminum phosphate per 100 parts by mass of active filler.

[0018] The active filler contained in the present mixture (hereinafter also referred to as "the present active filler") is an inorganic powder containing, as a main component, an aluminosilicate that is active against alkalis. When a small amount of water, for example, is added to this activated filler, the silicon and aluminum in the activated filler are partially dissolved or ionized, and when it comes into contact with the alkali source described below, the metal ions dissolved from the activated filler and the silica present in the alkali silica solution in a state close to a monomer undergo a dehydration condensation reaction, producing a hardened polymer compound and becoming a hardened alkali activated material composition. As a result, the active filler functions as a binder for the alkali-active material composition described below. Examples of the active filler include amorphous powders that are active in alkalis, such as fly ash (coal ash), metakaolin, and blast furnace slag.

[0019] Examples of the active filler include fly ash, bottom ash, rice husk ash, palm ash obtained by burning oil palm residue, waste glass, municipal waste incineration ash, sewage sludge incineration ash, blast furnace slag powder, metakaolin, silica fume, and powdered silica. These may be used alone or in combination of two or more. Among these, ground granulated blast furnace slag, fly ash, silica fume, and metakaolin are preferred because they can reduce the environmental load by effectively utilizing waste materials, can easily produce an alkaline active material composition, and are easy to obtain and handle.

[0020] The active filler preferably contains ground granulated blast furnace slag from the viewpoint of compressive strength of precast products obtained from the cured product of the alkali-activated material composition described below. Ground granulated blast furnace slag is recovered during the process of producing pig iron from iron ore by combining components other than iron contained in iron ore with the auxiliary raw materials limestone and ash from coke. The ground granulated blast furnace slag is preferably one whose particle size has been adjusted by pulverizing the blast furnace slag, etc. Examples of the ground granulated blast furnace slag include the ground granulated blast furnace slag used in JIS R 5211 "Blast furnace cement" and ground granulated blast furnace slag conforming to JIS A 6206 "Ground granulated blast furnace slag for concrete." The ground granulated blast furnace slag is preferably ground granulated blast furnace slag having a large Blaine value, which is the particle size determined by the Blaine method. Ground granulated blast furnace slag having a Blaine value of 4000 or more is more preferred, and ground granulated blast furnace slag having a Blaine value of 4000 is even more preferred. The ground granulated blast furnace slag having the above Blaine value can be made into ground granulated blast furnace slag having a desired Blaine value by, for example, pulverization, classification, etc.

[0021] When the present activated filler contains ground granulated blast furnace slag, the content is preferably 90% by mass or more, and more preferably 100% by mass, based on 100% by mass of the present activated filler, from the viewpoint of the compressive strength of the resulting precast product.

[0022] Furthermore, when the present active filler contains ground granulated blast furnace slag, it is preferable to contain, in addition to the ground granulated blast furnace slag, a compound having pozzolanic reactivity different from that of the ground granulated blast furnace slag, in order to promote the hardening reaction of the ground granulated blast furnace slag.

[0023] A substance with pozzolanic reactivity is a substance that has almost no hardening properties with water itself, but reacts with an alkali metal salt in the presence of water at room temperature to produce an insoluble compound that hardens. Examples of substances having pozzolanic reactivity include metakaolin, clay, sediments, minerals, silica-based particles, coal ash, etc. Specific examples of clay include kaolin, activated clay, acid clay, etc., sediments such as diatomaceous earth, minerals such as talc, silica-based particles such as silica dust, silica fume, aerosil, etc., and coal ash includes fly ash, white carbon, rice husk ash, etc.

[0024] Metakaolin is a kaolin (chemical composition: Al4Si4O 10 Metakaolin is amorphous and is produced by calcining ((OH)8, triclinic crystal system) at a temperature of about 500°C to 900°C to remove some of the water of crystallization. Metakaolin is preferably in powder form.

[0025] Among these, from the viewpoint of reducing the environmental load through the effective utilization of waste, it is preferable that the active filler contains silica-based particles and coal ash as compounds having pozzolanic reactivity, and it is more preferable that the active filler contains at least one of fly ash and silica fume.

[0026] Fly ash is a fine ash that is collected from exhaust gas using a dust collector or the like, among the coal ash generated when pulverized coal is burned in a coal-fired power plant. The main components of fly ash are silicon dioxide (SiO2), alumina (Al2O3), etc. Fly ash may or may not be specified by the JIS standard. As fly ash, those specified by the JIS in four types of quality (fly ash types I to IV) are preferred, and type II fly ash (JIS type II ash) is more preferred in terms of further increasing the strength of the hardened product.

[0027] Moreover, as fly ash, types F and C of the ASTM standard are preferable. When the mixture is used as an alkali activated material composition (described later) as a material for alkali activated material mortar, the active filler preferably contains fly ash classified as type I or type II.

[0028] Silica fume is amorphous fine particles of high-purity silicon dioxide contained in dust generated during the production of, for example, ferrosilicon, metallic silicon, or electrofused zirconia. When the active filler contains silica fume, the silica fume preferably has an average particle size of 100 nm to 45 μm. The average particle size is the volume average particle size, and is the D50 value that can be measured using a laser diffraction particle size analyzer or the like. D50 can be measured by dynamic light scattering. The specific surface area of ​​silica fume is 15m 2 / g or more 30m 2 The specific surface area can be measured by, for example, the BET method. The specific surface area determined by the BET method can be determined by nitrogen gas adsorption measurement, and can be measured using, for example, a specific surface area measuring device.

[0029] When the present active filler contains the compound having pozzolanic reactivity, the active filler preferably contains the compound having pozzolanic reactivity in an amount of 20% by mass or more and 80% by mass or less. That is, when the total amount of the present active filler is taken as 100 mass %, the amount of the compound having pozzolanic reactivity in the present active filler is preferably 20 mass % or more and 80 mass % or less. When the present active filler contains the compound having pozzolanic reactivity, one or more of the compounds having pozzolanic reactivity may be used.

[0030] If the content of the compound having pozzolanic reactivity in the active filler is within the above range, when the mixture is formed into an alkaline active material composition as described below, an increase in viscosity of the resulting alkaline active material composition is suppressed, and the handleability is improved, and a decrease in fluidity is prevented, which is expected to reduce costs.

[0031] The mixture preferably contains the ground granulated blast furnace slag and the compound having pozzolanic reactivity as the active filler from the viewpoint of preventing a decrease in fluidity during hardening, and more preferably contains the ground granulated blast furnace slag and at least one of fly ash and silica fume, and even more preferably contains both. For example, the mixture preferably contains, as the active filler, 30% by mass or less of the ground granulated blast furnace slag, 55% by mass or more of the fly ash, and 15% by mass or less of silica fume, with the total amount of the active filler being 100% by mass, and more preferably contains 30% by mass or less of the ground granulated blast furnace slag and 70% by mass or more of the fly ash. When both fly ash and silica fume are contained, the content of silica fume is preferably 10% by mass or less, with the total amount of the present active filler being 100% by mass.

[0032] From the viewpoint of reducing carbon dioxide and achieving high early strength and long-term strength, it is preferable that the present active filler does not contain cement clinker.

[0033] The mixture contains 5 parts by mass or more and 25 parts by mass or less of an alkali source relative to 100 parts by mass of the active filler. The alkali source includes a substance that exhibits strong alkalinity when dissolved in water. Examples of the alkali source include alkali metal salts and alkaline earth metal salts. From the viewpoint of durability of the cured product of the alkali-activated material composition described below, alkali metal salts are preferred. Examples of the salt include silicates, hydroxides, carbonates, etc., and the salt may be in either a liquid or powder state, and may be any of an anhydrous salt, a hydrate, an aqueous solution, or an organic solvent solution.

[0034] The alkali source contained in the mixture is preferably at least one selected from the group consisting of sodium orthosilicate, sodium metasilicate, and an alkali solution, from the viewpoints of cost and strength development. Sodium orthosilicate is represented by Na4SiO4, and sodium metasilicate is represented by Na2SiO3. Both may contain water of crystallization. Sodium orthosilicate and sodium metasilicate may be in the form of powder or aqueous solution.

[0035] The alkaline solution may be, for example, a solution of an alkali metal salt or an alkaline earth metal salt, and is usually an aqueous solution of an alkali metal salt or an alkaline earth metal salt. As the alkali metal, lithium, sodium and potassium are preferred, and as the alkaline earth metal, beryllium, magnesium, calcium and strontium are preferred, with sodium, potassium, magnesium and calcium being preferred from the viewpoint of ease of handling.

[0036] The alkali metal salts or alkaline earth metal salts include silicates, hydroxides, and carbonates, but the sodium orthosilicate and sodium metasilicate solutions are excluded from the alkaline solution. The alkaline solution is preferably at least one aqueous solution selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, magnesium silicate, calcium silicate, lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, magnesium carbonate, and calcium carbonate, and more preferably at least one aqueous solution selected from the group consisting of sodium silicate, sodium hydroxide, and calcium hydroxide.

[0037] Among these, the alkali source is more preferably at least one selected from the group consisting of sodium metasilicate, sodium orthosilicate, sodium silicate, sodium hydroxide, and calcium hydroxide, and even more preferably sodium orthosilicate. Sodium orthosilicate may be in the form of either a powder or an aqueous solution, but from the viewpoint of ease of handling, a powder is preferred.

[0038] The mixture contains the alkali source in an amount of 5 to 25 parts by mass per 100 parts by mass of the active filler. When the alkali source is two or more selected from the group consisting of sodium orthosilicate, sodium metasilicate, and an alkali solution, the total amount thereof is 5 to 25 parts by mass. The content of the alkali source in the mixture is preferably 8 parts by mass or more per 100 parts by mass of the active filler, from the viewpoint of the strength of the resulting alkali-activated material cured product. The content of the alkali source in the mixture is preferably 16 parts by mass or less per 100 parts by mass of the active filler in view of fluidity during curing.

[0039] In addition to the present active filler and the alkali source, the present mixture contains at least one of aluminum sulfate and aluminum phosphate in an amount of 0.1 to 6.25 parts by mass per 100 parts by mass of the present active filler. It has been known that aluminum sulfate or aluminum phosphate has a setting-accelerating effect on cement compositions. The setting-accelerating effect accelerates hardening, which is usually expected to reduce the fluidity of the composition and lead to poor handling. However, it has been found that aluminum sulfate or aluminum phosphate has a setting retarding effect on the present mixture, although the reason is unclear. Due to this setting retarding effect, the present mixture and the alkaline active material composition containing the present mixture, which will be described later, are thought to have excellent fluidity and handleability.

[0040] From the viewpoint of the fluidity improving effect, the content of at least one of aluminum sulfate and aluminum phosphate in the mixture is preferably 0.4 parts by mass or more, more preferably 0.8 parts by mass or more, per 100 parts by mass of the active filler. Furthermore, from the viewpoint of the curing speed of the present mixture and the alkali-activated material composition containing the present mixture, the content of at least one of aluminum sulfate and aluminum phosphate in the present mixture is preferably 2.4 parts by mass or less, and more preferably 1.6 parts by mass or less, per 100 parts by mass of the present active filler.

[0041] When the mixture contains both aluminum sulfate and aluminum phosphate, the total amount of both in the mixture is within the above range, and the preferred ranges are the same.

[0042] The composition can be made into an alkali-activated material composition by further containing fine aggregate and water. Therefore, the alkali activated material composition of the present invention (hereinafter also referred to as "the present alkali activated material composition 1") contains 5 to 25 parts by mass of an alkali source and 0.1 to 6.25 parts by mass of at least one of aluminum sulfate and aluminum phosphate per 100 parts by mass of active filler, and further contains fine aggregate and water. The active filler contained in the alkali activated material composition 1 is the same as the active filler described above, and the alkali source and its content range, as well as its preferred range, are also the same as described above. The range and preferred range of the content of aluminum sulfate or aluminum phosphate contained in the alkaline active material composition 1 are also the same as those described above.

[0043] The fine aggregate contained in the alkali activated material composition 1 is, for example, aggregate having a particle size of about 0.75 mm or more and 5 mm or less, commonly known as sand, and includes various fine aggregates conventionally used in mortar. Examples of fine aggregates include river sand, mountain sand, land sand, sea sand, silica sand, crushed sand, blast furnace slag fine aggregate, and recycled fine aggregate derived from concrete waste. Examples of crushed stone include crushed stone such as andesite, rhyolite, hard sandstone, and limestone. As the blast furnace slag fine aggregate, an article conforming to the standard "Slag aggregate for concrete - Part 1: Blast furnace slag aggregate" described in JIS A5011-1:2018 is preferable.

[0044] Silica sand is a sandy material made up of minerals whose main component is silicon dioxide (SiO2). Silica sand is classified by particle size in the Japanese Industrial Standards (JIS G 5901). When using silica sand as fine aggregate, No. 5 silica sand as specified in the Japanese Industrial Standards is preferred.

[0045] The alkali activated material composition 1 may contain one or more of the above fine aggregates. The type of fine aggregate is appropriately selected depending on the desired mechanical strength of the alkali-activated material hardened product obtained by hardening the alkali-activated material composition.

[0046] The alkali active material composition 1 contains water, which is the site where the components and base contained in the active filler are dissolved or ionized, and where the alkali active material structure is formed by a polycondensation reaction. The water contained in the alkaline active material composition 1 may be tap water, pure water, distilled water, industrial water, or the like.

[0047] In the present alkali activated material composition 1, the amount of water is preferably 35 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the activated filler. In addition, the alkali activated material composition 1 preferably contains the fine aggregate in an amount of 140 parts by mass or more and 180 parts by mass or less per 100 parts by mass of the active filler.

[0048] The present alkali active material composition 1 may further contain coarse aggregate (hereinafter also referred to as "the present alkali active material composition 2"). The coarse aggregate contained in the alkali activated material composition 2 is, for example, an aggregate having a particle size of about 5 mm or more and 25 mm or less, and examples thereof include various coarse aggregates conventionally used in concrete. Examples of coarse aggregate include crushed stone such as andesite, rhyolite, hard sandstone, and limestone, river gravel, mountain gravel, land gravel, blast furnace slag coarse aggregate, and recycled coarse aggregate derived from concrete waste.

[0049] In the present alkaline active material composition 2, the amount of the water is preferably 35 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the active filler. In addition, the alkali activated material composition 2 preferably contains the coarse aggregate in an amount of 200 parts by mass or more and 250 parts by mass or less per 100 parts by mass of the active filler.

[0050] The present alkali activated material compositions 1 and 2 may contain other components, as needed, that are used in ordinary concrete compositions, depending on the conditions of use, etc. Examples of such other components include thickeners, bleeding inhibitors, shrinkage reducers, hardening accelerators, fillers, fibers, air-entraining agents, surfactants, and retarders.

[0051] Examples of thickeners include compounds with thickening effects, such as inorganic derivatives such as clay and talc, acrylic or acrylamide (co)polymers, natural polysaccharides such as celluloses and gums, and polysaccharide derivatives.

[0052] Examples of the bleeding inhibitor include the thickeners, polyalkylene oxides, highly water-absorbent polymers, and amine salts.

[0053] Examples of shrinkage-reducing agents include known chemical substances that are known to have a shrinkage-reducing effect in alkali-activated material mortar or alkali-activated material concrete. Specific examples of shrinkage reducing agents include ester compounds having an oxyalkylene group, ether compounds having an oxyalkylene group, and glycol compounds having an oxyalkylene group.

[0054] Examples of the hardening accelerator include components for accelerating the hardening of sodium silicate, potassium silicate, lithium silicate, or a mixture thereof. The hardening accelerator is preferably a compound that adjusts the pH to near neutral in order to accelerate the dehydration reaction. Furthermore, in order to form a Si-O-metal-O-Si bond and accelerate hardening, it is preferable that the alkali metal in sodium silicate, potassium silicate, lithium silicate, or a mixture thereof be replaced with a divalent or higher metal. The curing accelerator preferably contains one or more compounds selected from the group consisting of organic acid esters, dialdehydes, inorganic acid esters, organic acid metal salts, inorganic acid metal salts, metal oxides, and metal hydroxides, and more preferably uses one or more compounds selected from the group consisting of organic acid esters, metal oxides, and metal hydroxides.

[0055] Organic acid esters have the advantage of being able to promote the formation of Si-O bonds by generating acid in an aqueous solution. Examples of organic acid esters include carbonate esters and acetate esters. Among these, triacetin is preferred. An example of the dialdehyde is malondialdehyde. Examples of inorganic acid esters include esters of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, etc., such as trimethyl phosphate. Examples of organic acid metal salts include alkali metal and alkaline earth metal salts of formic acid, acetic acid, malonic acid, carbonic acid, etc., such as sodium hydrogen carbonate. Examples of inorganic acid metal salts include alkali metal and alkaline earth metal salts of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, etc., such as magnesium sulfate. Metal oxides and hydroxides form Si-O-metal-O-Si bonds by dissolving metal ions, and can harden, for example, sodium silicate, potassium silicate, lithium silicate, or mixtures thereof. Examples of metal oxides and hydroxides include magnesium hydroxide, magnesium carbonate, calcium carbonate, and calcium hydroxide.

[0056] As the curing accelerator, magnesium hydroxide and magnesium carbonate are preferred from the viewpoints of preventing precipitation of the curing agent in the alkaline active material composition and facilitating impregnation into glass fibers.

[0057] Examples of fillers include organic fillers such as cellulose, and inorganic fillers such as carbon, mineral fine powder, synthesized inorganic crystal powder, calcium carbonate, etc. Examples of mineral fine powders include greywacke powder, silica sand powder, zeolite, zirconia, and silica powder.

[0058] The fibers are preferably those having a reinforcing property, such as metal fibers, carbon fibers, glass fibers, and basalt fibers.

[0059] Air entraining agents (AE agents) are a type of surfactant used to uniformly entrain many independent fine air bubbles in concrete, thereby improving workability and frost resistance. Surfactants are classified into anionic, cationic, nonionic and amphoteric types depending on their ionization in aqueous solution, but commercially available AE agents include anionic types such as resin-based, alkylbenzene sulfonate-based and higher alcohol ester-based types, as well as nonionic types.

[0060] In addition to the AE agent, a surfactant may be used to stabilize the dispersion of the alkaline active material composition. The surfactant used for this purpose may be any of anionic, cationic and nonionic surfactants, with nonionic surfactants being preferred. Examples of anionic surfactants include sodium lauryl sulfate, sodium lauryl sulfate, and sodium linear alkylbenzene sulfonate. Examples of cationic surfactants include tetramethylammonium chloride, tetramethylammonium hydroxide, and monomethylamine hydrochloride. Examples of nonionic surfactants include sorbitan fatty acid esters, sucrose fatty acid esters, polyoxyethylene alkyl ethers, octaethylene glycol monododecyl ether, polyoxyethylene alkylphenyl ethers, polyoxyethylene polyoxypropylene glycol, and lauric acid diethanolamide.

[0061] Retardants include sucrose, sodium tartrate, citric acid, metal chelating agents, and the like.

[0062] The other components can be used in any amount in the present alkaline active material compositions 1 and 2, but it is generally preferable that they be blended in an amount of 10 mass % or less, with the total mass of the present alkaline active material compositions 1 or 2 being 100 mass %.

[0063] From the viewpoint of carbon dioxide reduction effect, it is preferable that the present alkali activated material compositions 1 and 2 contain neither Portland cement nor blended cement.

[0064] The present alkali-activated material compositions 1 and 2 can be obtained by mixing and kneading the present active filler, alkali source, at least one of aluminum sulfate and aluminum phosphate, fine aggregate, water, and, if necessary, coarse aggregate. These components may be mixed together in a lump and then kneaded, or may be added sequentially and mixed, or a plurality of components may be mixed separately and then kneaded together. Preferably, dry kneading is performed by first mixing the ingredients other than water, and then water is added and kneaded. When dry kneading is performed, the time is preferably 1 minute or less, more preferably 30 seconds or less, and even more preferably 15 seconds or less. For the mixing and kneading method, a common mixer or kneader such as a single-screw or twin-screw mixer is used.

[0065] The present alkali active material compositions 1 and 2 (hereinafter, both may be collectively referred to as "the present alkali active material compositions") are cured to obtain a cured alkali active material. The method for producing a cured alkali active material obtained from this alkali active material composition (hereinafter also referred to as "this production method") involves kneading the alkali active material composition and carrying out curing, including preliminary curing and steam curing, at an accumulated temperature of 250°C·hours or more.

[0066] The kneading in the present production method is carried out by placing the present active filler, alkali source, at least one of aluminum sulfate and aluminum phosphate, fine aggregate, water, and, if necessary, coarse aggregate in a mechanical mixer, followed by stirring, mixing, and kneading. The mixer used for kneading sufficiently stirs the above components to promote the condensation polymerization reaction of silicon and aluminum. Examples of mixers used for kneading include mortar mixers (JIS R5201 compliant) similar to those used for cement concrete, pan mixers, and forced twin-screw mixers.

[0067] The kneading may be carried out by the same methods as those used for the above-mentioned Alkali Activated Material Compositions 1 and 2, and the preferred methods are also the same. For example, it is preferable to add the active filler, or if necessary, a powder containing a compound having pozzolanic reactivity, and aggregate containing fine blast furnace slag aggregate to the mixer, dry-knead the mixture, and then add an alkali source, at least one of aluminum sulfate and aluminum phosphate, and water. Alternatively, kneading may be carried out at two speeds, a low speed and a high speed. The dry kneading time, including the preferred time, is the same as above.

[0068] In this manufacturing method, after the kneading, curing including preliminary curing and steam curing is carried out at an accumulated temperature of 250°C·hours or more. Pre-curing is carried out before steam curing, which will be described later, and is usually carried out at around room temperature, which is usually between 10°C and 40°C. Steam curing is an accelerated curing process carried out in high-temperature steam. Steam curing carried out under atmospheric pressure is called normal pressure steam curing, while steam curing carried out using high-temperature steam at a pressure higher than normal pressure is called high-temperature / high-pressure steam curing. In this manufacturing method, normal pressure steam curing is preferred from the viewpoint of equipment, etc.

[0069] In this manufacturing method, pre-curing and steam curing are carried out at an accumulated temperature of 250°C·hours or more. The accumulated temperature is expressed as the product of temperature and time, and is expressed by the following integral formula (1). Accumulated temperature = ∫Tdt (1) In equation (1), dt is the micro-time of pre-curing and steam curing, and T is the temperature at the micro-time dt of pre-curing and steam curing, which is a function of t. Therefore, the above formula (1) means that the temperatures during pre-curing and steam curing are integrated by the time periods for pre-curing and steam curing.

[0070] In this production method, by carrying out the curing, including the pre-curing and steam curing, at an accumulated temperature of 250°C·hours or more, the reaction between the silicon and aluminum contained in the alkali active material composition and the alkali contained in the alkali source proceeds sufficiently, and the alkali active material composition hardens to produce a hardened alkali active material. Furthermore, by carrying out pre-curing and steam curing at an accumulated temperature of 250°C·hours or more, the resulting hardened alkali-activated material has high compressive strength and excellent length stability.

[0071] The pre-curing and steam curing may be repeated as long as the above-mentioned range of accumulated temperature is satisfied, but it is preferable to carry out the steam curing after the completion of the pre-curing. From the viewpoint of the man-hours and the obtained effects, the cumulative temperature is preferably 570°C·hours or less, and more preferably 500°C·hours or less.

[0072] The temperature for pre-curing is preferably 20°C or higher, more preferably 30°C or higher, from the viewpoint of easily satisfying the range of the accumulated temperature. The time for pre-curing is preferably 3 hours or longer, from the viewpoint of easily satisfying the range of the accumulated temperature. The temperature of the pre-curing may vary during the pre-curing, but is preferably constant from the viewpoint of ease of temperature control. The temperature of the steam curing may vary during the steam curing, but is preferably constant from the viewpoint of ease of temperature control.

[0073] It is more preferable to select the temperature of pre-curing from 20°C to 40°C for 1 hour to 5 hours, and the temperature of steam curing from 50°C to 80°C for 2 hours to 10 hours so as to satisfy the above-mentioned ranges of the accumulated temperature.

[0074] When pre-curing and steam curing are performed at a constant temperature during each curing, the cumulative temperature can be derived from the above formula (1) as follows: Accumulated temperature = ΣT n ×t n + ΣT k ×t k (2) In equation (2), T n and t n is the temperature and time of the nth pre-curing, T k and t k are the temperature and time of the kth steam curing, where n and k are integers greater than or equal to 1.

[0075] In this manufacturing method, other curing such as heat curing, autoclave curing, water curing, air curing, room temperature curing, sealed curing, and combinations thereof may be performed as long as the pre-curing and steam curing satisfy the above-mentioned range of accumulated temperatures. Usually, it is preferable to perform other curing after the pre-curing and steam curing are completed. In the present production method, the alkali activated material composition may be subjected to a treatment such as degassing during curing.

[0076] The alkali-activated material cured product obtained by this production method using the alkali-activated material composition 1 becomes alkali-activated material mortar. Furthermore, the alkali active material hardened product obtained by this production method using the alkali active material composition 2 becomes alkali active material concrete.

[0077] As described above, the cured alkali-activated material obtained by this production method has a small rate of change in length and excellent dimensional stability. Therefore, it is thought that the cured alkali-activated material obtained using this alkali-activated material composition and this manufacturing method has a chemical structure or morphology that is different from that of conventional cured alkali-activated materials, but the details are not known.

[0078] By pouring the alkali-activated material composition into a mold and allowing it to harden, it is possible to obtain alkali-activated material hardened products in various shapes. When the present alkali-activated material composition is poured into a mold and cured, a mold release agent such as wax may be applied to the inside of the mold to facilitate removal of the cured alkali-activated material from the mold. The formwork may be made of wood or metal such as steel, similar to those conventionally used as concrete formwork. Examples of the release agent include petroleum wax, animal and vegetable wax, mineral wax, and synthetic wax.

[0079] Additionally, the alkali active material composition can be a precast product. Examples of precast products include road or bank protection blocks, blocks for storm drains or irrigation channels, tiles, bricks, sewer pipes, piles, poles, sleepers, and the like. When the present alkali activated material composition is made into the precast product, the molding method includes, for example, centrifugal molding, vibration molding, and pour molding.

[0080] The above has described the mixture, the alkali active material composition, the production method, the alkali active material cured product obtained from the alkali active material composition by the production method, and the precast product obtained from the alkali active material composition and the production method thereof. However, the present invention is not limited to the configuration of the above embodiment. In the compositions of the above-described embodiments, any other optional components may be added to the mixture, the alkali-active material composition, the alkali-active material cured product obtained from the alkali-active material composition by the production method, and the precast product obtained from the alkali-active material composition, or any other components that exhibit similar functions may be substituted. Furthermore, the present manufacturing method and the method for manufacturing a precast product obtained from the present alkali-activated material composition may have any other optional step added to the configuration of the above embodiment, or may be replaced with any other step that produces a similar effect. [Example]

[0081] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0082] Example 1 (Creating a mixture) Ground blast furnace slag (manufactured by Nippon Steel Slag Products Co., Ltd.) was used as an active filler. 3 700 kg of blast furnace slag per 1 m was mixed with 110 kg of sodium orthosilicate (manufactured by Nippon Chemical Industry Co., Ltd.) as an alkali source, 11 kg of aluminum sulfate (manufactured by Asada Chemical Industry Co., Ltd.), and 1087 kg of sand for cement strength test specified in JIS R 5201 as fine aggregate. 3 I got 1908kg per piece. The ground granulated blast furnace slag used contained gypsum.

[0083] The mixture obtained above 1, 1 m 3 1908 kg per 1 m 3 The alkaline active material composition A was obtained by mixing and kneading the mixture with 300 kg of water per 1000g of the raw material.

[0084] (Comparative Examples 1 to 3) Alkaline active material compositions B to D were obtained in the same manner as in Example 1, except that aluminum sulfate was used in the proportions shown in Table 1.

[0085] [Table 1]

[0086] (Flow Value Measurement of Alkaline Activated Material Composition) The flow value of the alkaline active material composition obtained above was measured under the following conditions, and the results are shown in Table 2. In Table 2, the JIS flow value (mm) is a value indicating fluidity, that is, the amount of fluid spreading. In Table 2, the flow value of the alkaline active material composition is expressed in units of [mm], and it can be said that the larger this value, the higher the fluidity. The measurement conditions for the JIS flow value are as follows:

[0087] (Flow value measurement conditions) Flow was measured according to "12 Flow Test" of IS R 5201 "Methods of Physical Testing of Cement". It is considered desirable for the workability of mortar to have a flow value of 160 mm or more after being dropped 15 times.

[0088] In Table 2, the mixing temperature (°C) is the temperature (°C) immediately after the alkaline active material compositions A to D obtained in Example 1 and Comparative Examples 1 to 3 are obtained, the initial time (minutes) is the time (minutes) at which the alkaline active material compositions A to D start to solidify, and the final time (minutes) is the time (minutes) at which the alkaline active material compositions A to D finish solidifying. Sealing at 20℃ (1d) (N / mm 2 ) is the compressive strength (N / mm 2 ), 20℃ sealed (14d) (N / mm 2 ) is the compressive strength (N / mm) of the hardened product of alkaline activated material compositions A to D after 14 days of sealed curing at 20°C. 2)

[0089] The setting start time (minutes) and setting completion time (minutes) were measured according to the conditions and method described in "9. Setting test" of JIS R 5201 "Physical testing methods for cement." Compressive strength of the hardened product after 1 day of sealed curing at 20°C (N / mm 2 ), compressive strength of the cured product after 14 days of sealed curing at 20°C (N / mm 2 ) was measured at 1 day and 14 days (high temperature curing conditions, sealed curing conditions) according to "11 Strength test" in JIS R 5201 "Physical testing methods for cement."

[0090] [Table 2]

[0091] As is clear from Table 2, the alkaline active material composition of the present invention is excellent in flow value.

[0092] (Examples 2 to 5) The compressive strength of each alkaline activated material composition was measured using alkaline activated material compositions E to H obtained in Examples 2 to 5 in the same manner as in Example 1, except that the formulations were as shown in Table 3. The handleability was also evaluated by the following method. The results are shown in Table 3.

[0093] For comparison with Examples 2 to 6, the same formulation as in Example 1 was used as a reference example, and the resulting alkaline activated material composition A was also subjected to measurement of compressive strength and evaluation of handleability.

[0094] [Reference example] (Creating a mixture) Ground blast furnace slag (manufactured by Nippon Steel Slag Products Co., Ltd.) was used as an active filler. 3700 kg of blast furnace slag per 1 m was mixed with 110 kg of sodium orthosilicate (manufactured by Nippon Chemical Industry Co., Ltd.) as an alkali source, 11 kg of aluminum sulfate (manufactured by Asada Chemical Industry Co., Ltd.), and 1,087 kg of crushed sand from hard limestone (Ibuki production area) as fine aggregate. 3 I got 1908kg per piece. The ground granulated blast furnace slag used contained gypsum. 1 m of the mixture 2 obtained above 3 1908 kg per 1 m of water 3 The mixture was mixed and kneaded in an amount of 300 kg per 1000 ml to obtain an alkaline active material composition A. The results are also shown in Table 3.

[0095] In Table 3, 20℃ sealing (1d) (N / mm 2 ) and 20℃ sealing (14d) (N / mm 2 ) are the same as above. The handling property was determined by measuring the flow value and rated as either O or X according to the following definitions. ○: JIS flow value is 160mm or more ×: JIS flow value is less than 160 mm Generally, the slump value required for centrifugal molding, vibration molding, and pour molding when aggregate is included is 4.5cm or more, which is the fluidity required. In order to satisfy this slump value, a JIS flow value of 160mm or more is considered necessary, so a JIS flow value of 160mm or more is considered to have excellent handleability and is marked with a ○.

[0096] Sealing at 65℃ (1d) (N / mm 2 ) is the compressive strength (N / mm) of the hardened product of alkaline activated material compositions A, E to H after one day of sealed curing at 65°C. 2 ), 65℃ sealed (14d) (N / mm 2 ) is the compressive strength (N / mm) of the hardened product of alkaline activated material compositions A, E to H after 14 days of sealed curing at 65°C. 2 ) Compressive strength was measured at 1 day and 14 days (high temperature curing conditions, sealed curing conditions) according to "11 Strength test" in JIS R 5201 "Physical testing methods for cement." The compressive strength results in Table 3 are shown in Figure 1.

[0097] [Table 3]

[0098] The results in Table 3 and Figure 1 show that by increasing the amount of alkali in the alkali-activated material composition, it is possible to increase the strength of the resulting hardened product without causing a deterioration in handleability, and to obtain strength equal to or greater than that of conventional cement.

[0099] Examples 6 and 7 Alkaline active material compositions I and J were obtained in Examples 6 and 7 in the same manner as in Example 1, except that the formulations shown in Table 4 were used. Using the obtained alkaline activated material compositions I and J, the compressive strength of each alkaline activated material composition was measured, and further, the handling properties were evaluated. In Examples 6 and 7, fly ash (JIS type 2 from Kansai Electric Power Maizuru) and the same ground granulated blast furnace slag as in the Reference Example were used as the active filler.

[0100] In Table 4, handling property and 20℃ sealing (1d) (N / mm 2 ) is the same as above. Pre-curing 3 hours → 65℃ 3 hours → 20℃ sealing (N / mm 2 ) is the compressive strength of the hardened material after pre-curing at 20°C, steam curing at 65°C for 3 hours, and then sealed curing at 20°C for 1 day. Pre-curing 3 hours → 65℃ 6 hours → 20℃ sealing (N / mm 2 ), pre-curing for 6 hours → 65℃ for 3 hours → sealing at 20℃ (N / mm 2 ) is also the same. The conditions for measuring the compressive strength are as follows. The curing conditions were changed and the rate of change in length of the cured product of each alkali activated material composition was measured. Pre-curing was carried out at 20°C. For comparison, the alkali activated material composition A obtained in Reference Example was also subjected to measurements of the length change rate and compressive strength of the hardened product when the curing conditions were changed. The length change rate was measured by the following method and conditions.

[0101] (Evaluation of length change rate and compressive strength) Using the alkaline active material compositions shown in Table 4, the rate of change in length with time was measured. The rate of change in length was measured according to the method and conditions specified in JIS A 1129-3. The compressive strength was measured in accordance with "11 Strength Test" of JIS R 5201 "Physical Testing Methods for Cement" at a material age of 1 day under high temperature curing and sealed curing conditions. The results are shown in Figures 2 to 4. In Figures 2 to 4, pre-curing refers to preliminary curing.

[0102] [Table 4]

[0103] Figures 2 to 4 show the rate of change in length on the vertical axis and the age of the dried timber in days on the horizontal axis. 2 to 4, the curing of the alkali-activated material compositions shown in Table 4 was performed by sealing with a circle, pre-curing for 3 hours at 20°C followed by steam curing for 3 hours at 65°C with a square, pre-curing for 3 hours at 20°C followed by steam curing for 3 hours at 65°C with a diamond, and pre-curing for 3 hours at 20°C followed by steam curing for 6 hours at 65°C with a triangle. FIG. 2 shows the results when alkaline active material composition A was used, FIG. 3 shows the results when alkaline active material composition I was used, and FIG. 4 shows the results when alkaline active material composition J was used. The accumulated temperatures in Figures 2 to 4 were 255°C·h, 450°C·h, and 510°C·h, respectively. From the results shown in Figures 2 to 4, by kneading this alkali-activated material composition and curing it, including preliminary curing and steam curing, at an accumulated temperature of 250°C·hours or more, it is possible to obtain a hardened alkali-activated material with a small dimensional change rate.

[0104] Example 8 (Creating a mixture) Ground blast furnace slag (manufactured by Nippon Steel Slag Products Co., Ltd.) was used as an active filler. 3 440 kg of blast furnace slag was mixed with 70 kg of sodium orthosilicate (manufactured by Nippon Chemical Industry Co., Ltd.) as an alkali source, 7 kg of aluminum sulfate (manufactured by Asada Chemical Industry Co., Ltd.), 685 kg of crushed hard limestone (Ibuki production area) sand as fine aggregate, and 1,000 kg of limestone as coarse aggregate, and the mixture was poured into a 1 m 3 I got 2202kg per piece. The ground granulated blast furnace slag used contained gypsum. 1 m of the mixture 11 obtained above 3 1m of water for 2202kg per 3 The alkaline active material composition K was obtained by mixing and kneading 190 kg per unit weight. The alkali active material composition K corresponds to the alkali active material composition 2, and the hardened product becomes alkali active material concrete. Formulation of alkaline active material composition K and 65°C steam (1d) (N / mm 2 ), 65℃ steam (14d) (N / mm 2 ) The results are shown in Table 5. At 65℃ steam (1d) (N / mm 2 ) and 65℃ steam (14d) (N / mm 2 ) is the same as above. In Table 5, the slump value (cm) was measured in accordance with JIS A 1101 concrete slump test method.

[0105] [Table 5]

[0106] (Precast product manufacturing) A precast product was produced using the alkali activated material composition K, and its physical properties were measured. The specifications of the precast product specimens were as follows: 1) Dimensions, shape (type) and number The number of specimens was in accordance with JSWAS A-6 (Japan Sewage Works Association standard), and a total of two specimens were produced, one for confirming external pressure strength and one for confirming joint watertightness. The dimensions and shape were as shown in Table 6. The minimum diameter required by the A-6 standard was also used to confirm the pipe manufacturing process and the finished product.

[0107] [Table 6] In accordance with the Japan Sewerage Association standard JSWAS A-6 watertightness test, two pipes were joined with an extraction length of 0 mm using the equipment for watertightness testing of joints shown in Figure 5, and then the joint was sealed with water from the outside or inside, and a water pressure (0.1 MPa) corresponding to the joint performance classification was applied and maintained for 3 minutes.

[0108] 2) Reinforcement specifications The rebar specifications are the same as those for JSWAS A-6 standard products. 3) Composition The alkaline active material composition L shown in Table 5 was kneaded in a small mixer. 4) Manufacturing method The manufacturing method was the same as that used for JSWAS A-6 standard products.

[0109] (Compressive strength of concrete) The compressive strength of the concrete was measured in accordance with JIS A 1108, a method for testing the compression of concrete. Three test pieces were prepared using a Φ20 x 10 cm summit mold, and the compressive strength was checked after the specified steam curing period at 14 days of age. The results of the compressive strength test are shown in Table 5.

[0110] (External pressure strength) The external pressure strength and test method were as specified in the Sewerage Association Standard JSWAS A-6. The results of the external pressure strength, crack load and fracture load, are shown in Table 7. The test method used was the device shown in Figure 6. The age of the specimen was confirmed at 14 days. Regarding the breaking load, the test was stopped at 200% of the specification, taking into consideration quality and safety.

[0111] [Table 7]

[0112] The above test results demonstrate that the performance of the precast products obtained from the alkali-activated material composition is sufficient for practical use.

[0113] From the above results, it was found that the alkali activated material composition had excellent fluidity during hardening, and the resulting hardened alkali activated material had sufficiently high compressive strength. Furthermore, the strength of precast products made using the alkali activated material composition fully satisfied the specifications for precast products. Furthermore, the cured product of the alkali-activated material obtained by this manufacturing method has a small rate of length change and excellent dimensional stability. Therefore, although the details are unknown, the cured product of the alkali-activated material obtained by this manufacturing method is thought to be different from conventional cured geopolymers.

Claims

1. A mixture containing 5 to 25 parts by mass of an alkali source and 0.1 to 6.25 parts by mass of at least one of aluminum sulfate and aluminum phosphate per 100 parts by mass of an active filler.

2. 2. The mixture of claim 1, wherein the alkali source is at least one selected from the group consisting of sodium orthosilicate, sodium metasilicate, and an alkali solution.

3. 3. The mixture of claim 2 wherein the alkaline source is sodium orthosilicate.

4. 2. The mixture of claim 1, wherein the active filler comprises ground granulated blast furnace slag.

5. The mixture of claim 4 wherein the active filler further comprises a compound having pozzolanic reactivity.

6. 6. The mixture according to claim 5, wherein the compound having pozzolanic activity is at least one of fly ash and silica fume.

7. An alkali-activated material composition containing, per 100 parts by mass of an activated filler, 5 parts by mass or more and 25 parts by mass or less of an alkali source, 0.1 parts by mass or more and 6.25 parts by mass or less of at least one of aluminum sulfate and aluminum phosphate, and further containing fine aggregate and water.

8. The alkali-activated material composition according to claim 7, further comprising coarse aggregate.

9. A method for producing a cured product of an alkali activated material, comprising kneading the alkali activated material composition according to claim 7 or 8, and carrying out curing including pre-curing and steam curing at an accumulated temperature of 250°C / hour or more.

10. A cured product of an alkali-activated material obtained by the method according to claim 9.

11. A precast product obtained from the alkali-activated material composition according to claim 7 or 8.

12. A method for producing a precast product, which comprises molding the alkaline activation material composition according to claim 7 or 8 by any one of centrifugal molding, vibration molding and pour molding.

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