Geopolymer composition and geopolymer cured body

Abstract

To provide a geopolymer composition that gives a cured product having a small neutralization speed, and a cured geopolymer having a small neutralization speed.SOLUTION: A geopolymer composition contains an active filler, a base, water, blast-furnace slag fine aggregate, and at least one selected from the group consisting of an ester compound having an oxyalkylene group, an ether compound having an oxyalkylene group and a glycol compound having an oxyalkylene group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to geopolymer compositions and geopolymer cured products. [Background technology]

[0002] Patent Document 1 discloses a shrinkage-reducing agent for geopolymers, which is an ester compound having an oxyalkylene group, and a geopolymer-forming composition and a cured geopolymer containing the shrinkage-reducing agent.

[0003] Patent Document 2 discloses a shrinkage-reducing agent for geopolymers, which is a glycol ether compound, as well as a geopolymer-forming composition and a cured geopolymer containing the shrinkage-reducing agent.

[0004] Patent Document 3 discloses a geopolymer admixture containing an oxyalkylene alkyl ether compound as a shrinkage reducing agent and an aliphatic oxycarboxylic acid compound as a shrinkage reducing aid, as well as a geopolymer-forming composition and a cured geopolymer containing the admixture.

[0005] Patent Document 4 discloses a geopolymer composition comprising an activated filler containing fly ash and blast furnace slag, an alkaline solution containing sodium silicate and / or sodium hydroxide, and a cement mineral-based expansive agent. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2017-202963 [Patent Document 2] Japanese Patent Publication No. 2018-150195 [Patent Document 3] Japanese Patent Publication No. 2017-202964 [Patent Document 4] Japanese Patent Publication No. 2020-055696 [Overview of the project] [Problems that the invention aims to solve]

[0007] It has been reported that cured geopolymers exhibit alkalinity initially and then become neutral, and the neutralization of cured geopolymers is thought to be due to carbonation.

[0008] The object of this disclosure is to provide a geopolymer composition that has a slow carbonation rate, and a geopolymer cured product that has a slow carbonation rate. [Means for solving the problem]

[0009] The following embodiments are included as specific means for solving the aforementioned problems. <1> A geopolymer composition comprising an active filler, a base, water, blast furnace slag aggregate, and at least one compound selected from the group consisting of ester compounds having oxyalkylene groups, ether compounds having oxyalkylene groups, and glycol compounds having oxyalkylene groups. <2> The total content of the ester compound having an oxyalkylene group, the ether compound having an oxyalkylene group, and the glycol compound having an oxyalkylene group is 0.5% to 5% by mass relative to the total amount of the active filler. <1> The geopolymer composition described above. <3> The active filler comprises at least one of fly ash and blast furnace slag fine powder. <1> or <2> The geopolymer composition described above. <4> <1> ~ <3> A geopolymer cured body which is a cured product of any one of the geopolymer compositions described in any one of the above. [Effects of the Invention]

[0010] This disclosure provides a geopolymer composition that has a slow carbonation rate, and a geopolymer cured product that has a slow carbonation rate. [Modes for carrying out the invention]

[0011] Embodiments of the invention are described below. These descriptions and embodiments are illustrative and do not limit the scope of the invention.

[0012] In this disclosure, the numerical range indicated using "~" includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in numerical ranges described within this disclosure, the upper or lower limit of that range may be replaced with the values ​​shown in the examples.

[0013] <Geopolymer composition> The geopolymer composition of this disclosure is a composition in a state referred to as slurry, fresh, etc., and a cured geopolymer body of this disclosure is obtained by curing the geopolymer composition of this disclosure.

[0014] The geopolymer composition of this disclosure comprises an active filler, a base, water, blast furnace slag aggregate, and at least one selected from the group consisting of ester compounds having an oxyalkylene group, ether compounds having an oxyalkylene group, and glycol compounds having an oxyalkylene group.

[0015] In this disclosure, ester compounds having an oxyalkylene group, ether compounds having an oxyalkylene group, and glycol compounds having an oxyalkylene group are collectively referred to as "chemical admixtures having an oxyalkylene group."

[0016] The inventors of this disclosure have found that neutralization of the hardened material is suppressed by replacing the fine aggregate of geopolymer mortar or geopolymer concrete from natural sand to blast furnace slag fine aggregate. Although not bound by any particular theory, it is presumed that the components contained in blast furnace slag aggregate exhibit similar reactivity to active fillers, causing the surface of the blast furnace slag aggregate to become part of the geopolymer structure. As a result, the bond between the blast furnace slag aggregate and the paste becomes stronger, and neutralization is suppressed compared to when natural sand is used as the aggregate.

[0017] Furthermore, the inventors of this disclosure have found that chemical admixtures having oxyalkylene groups have a neutralization-inhibiting effect on hardened geopolymers. While it was known that chemical admixtures having oxyalkylene groups exhibit a shrinkage-reducing effect in geopolymer mortar or geopolymer concrete (for example, Patent Documents 1 and 2), it was previously unknown that they exhibit a neutralization-inhibiting effect in geopolymer mortar or geopolymer concrete.

[0018] The materials constituting the geopolymer composition of this disclosure will be described in detail below.

[0019] [Activated filler] Activated fillers are generally powders whose main component is aluminum silicate. Examples of active fillers include fly ash, blast furnace slag powder, metakaolin, silica fume, zeolite powder, molten slag powder from waste incineration, molten sewage sludge powder, volcanic ash, rice husk ash, fluidized bed coal ash, paper mill sludge incineration ash, and mixtures of at least two of these.

[0020] An example of an active filler embodiment is a mixture of fly ash (FA) and blast furnace slag powder (BFS). Geopolymer compositions containing FA tend to have excellent fluidity and workability. Geopolymer compositions containing BFS tend to have high compressive strength in the cured product. By mixing FA and BFS, a geopolymer cured product with a good balance of fluidity, workability, and mechanical strength can be obtained.

[0021] The quality of FA (e.g., density, fineness), the quality of BFS (e.g., density, fineness), and the mixing ratio of FA to BFS are not limited and should be selected according to the target fluidity, workability, pot life, setting time, pore structure, mechanical strength, etc. Examples of factory automation (FA) include types I, II, III, and IV as defined in JIS A6201:2015. Examples of BFS include blast furnace slag fine powders of grades 3000, 4000, 6000, and 8000 as specified in JIS A6206:2013.

[0022] [Bases and Water] Bases are also called alkaline activators or alkaline stimulants in this field. A base is generally at least one selected from the group consisting of alkali metal silicates, alkali metal carbonates, and alkali metal hydroxides. Specifically, the base can be at least one selected from the group consisting of sodium silicate, potassium silicate, sodium carbonate, potassium carbonate, sodium hydroxide, and potassium hydroxide.

[0023] When alkali metal silicates are used as a base, it is thought that at least some of the silicon atoms contained in the base are incorporated into the geopolymer structure. Metal ions derived from bases (e.g., Na + , K + At least a portion of these is thought to be retained between the geopolymer structures.

[0024] Water is the site where components and bases contained in the active filler dissolve or ionize, and where the geopolymer structure is formed by condensation polymerization.

[0025] The bases and water contained in geopolymer compositions generally originate from alkaline solutions. That is, the bases and water are incorporated into the geopolymer composition by mixing the active filler with an alkaline solution. In other words, a geopolymer composition containing an active filler, a base, and water is a geopolymer composition obtained by mixing an active filler with an alkaline solution.

[0026] Examples of alkaline solutions used in forming the geopolymer composition include sodium silicate solution (sodium silicate water glass), potassium silicate solution (potassium silicate water glass), aqueous sodium carbonate solution, aqueous potassium carbonate solution, aqueous sodium hydroxide solution, aqueous potassium hydroxide solution, and mixtures of at least two of these. Water may also be added to ensure workability.

[0027] The type and concentration of the alkaline solution used to form the geopolymer composition should be selected according to factors such as ensuring a pot life based on the reactivity of the base and the mechanical strength after curing.

[0028] One example of an alkaline solution is a mixture of sodium silicate solution (sodium silicate water glass) and sodium hydroxide aqueous solution.

[0029] [Blast furnace slag fine aggregate] As blast furnace slag fine aggregate, products conforming to the JIS A5011-1:2018 "Slag aggregate for concrete - Part 1: Blast furnace slag aggregate" standard are preferred.

[0030] Blast furnace slag fine aggregate can be classified, for example, by particle size, density, water absorption rate, or combinations thereof, and the appropriate classification can be selected and used according to the target mechanical strength of the geopolymer cured body.

[0031] The geopolymer composition of this disclosure may contain other fine aggregates besides blast furnace slag fine aggregate. In the geopolymer composition of this disclosure, the mass ratio of blast furnace slag fine aggregate to the total fine aggregate is, for example, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, and 100% by mass.

[0032] [Other aggregates] The geopolymer composition of this disclosure may contain aggregates other than blast furnace slag fine aggregate. Examples of other aggregates include various fine and coarse aggregates conventionally used in geopolymer mortar or concrete or cement mortar or concrete.

[0033] Other fine aggregates besides blast furnace slag include, for example, river sand, mountain sand, land sand, sea sand, silica sand, crushed sand, crushed limestone sand, and recycled fine aggregate derived from concrete waste. Examples of coarse aggregates include crushed stone obtained by crushing andesite, rhyolite, hard sandstone, and limestone, as well as river gravel, mountain gravel, land gravel, blast furnace slag coarse aggregate, and recycled coarse aggregate derived from concrete waste. The type and content of these aggregates should be selected according to the target mechanical strength of the hardened geopolymer.

[0034] [Chemical admixture containing an oxyalkylene group] Chemical admixtures containing oxyalkylene groups (ester compounds containing oxyalkylene groups, ether compounds containing oxyalkylene groups, and glycol compounds containing oxyalkylene groups) exhibit a neutralization inhibitory effect in cured geopolymers.

[0035] In the geopolymer composition of this disclosure, the content of the chemical admixture having an oxyalkylene group is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 1.5% by mass or more, and still more preferably 2% by mass or more, based on the total amount of active filler, from the viewpoint of suppressing the neutralization of the geopolymer cured product. In the geopolymer composition of this disclosure, the content of the chemical admixture having an oxyalkylene group is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, based on the total amount of active fillers, from the viewpoint of ensuring the compressive strength of the cured geopolymer.

[0036] Specific examples of the chemical admixture having an oxyalkylene group include a chemical substance represented by the following formula (1), a chemical substance represented by formula (2), a chemical substance represented by formula (3), a chemical substance represented by formula (4), and a chemical substance represented by formula (5).

[0037] Formula (1) R 1 -C(=O)-O-(A 1 O) n1 -R 2

[0038] In formula (1), R 1 is an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms, A 1 O is a divalent alkylene oxide group having 2 to 4 carbon atoms, n1 is the average number of moles of alkylene oxide added and is a number from 1 to 200, R 2 is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms or a -C(=O)-R 3 group, and R 3 is an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms.

[0039] Formula (2) [HO-C(=O)-] k R 4 [-C(=O)-O-(A 2 O) n2 -R 5 m

[0040] In formula (2), R 4 is a residue obtained by removing (k + m) carboxy groups from a (k + m)-valent polycarboxylic acid having 1 to 30 carbon atoms, or a single bond, and k and m are integers satisfying the relationship of 0 ≦ k ≦ 5, 1 ≦ m ≦ 6, and 2 ≦ k + m ≦ 6, A 2 O is a divalent alkylene oxide group having 2 to 4 carbon atoms, n2 is the average number of moles of alkylene oxide added and is a number from 1 to 200, and R 5 is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms. R 4 ​In this case, the carbon atoms of the carboxyl group (-COOH) are not included in the number of carbon atoms of the polycarboxylic acid.

[0041] Equation (3) [R 7 -(OA 3 ) n3 -O-] p R 6 [-OC(=O)-R 8 ] q

[0042] In formula (3), R 6 R is a residue obtained by removing (p+q) hydroxyl groups from a (p+q) valent polyhydric alcohol with 2 to 30 carbon atoms, 7 is a hydrogen atom or -OC(=O)-R 9 It is the basis, OA 3 R is a divalent oxyalkylene group with 2 to 4 carbon atoms, n3 is the average number of moles of oxyalkylene added, and is a number from 1 to 200. 8 R is an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms. 9 is an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms, and p and q are integers satisfying the relationships 1 ≤ p ≤ 7, 1 ≤ q ≤ 7, and 2 ≤ p + q ≤ 8.

[0043] Formula (4) [H-(OA 4 ) n4 -O-] r R 10 [-O-(A 5 O) n5 -C(=O)-R 11 ] s

[0044] In formula (4), R 10 OA is a residue obtained by removing (r+s) hydroxyl groups from a polyhydric alcohol with 2 to 30 carbon atoms and (r+s) valence. 4 n4 is a divalent oxyalkylene group with 2 to 4 carbon atoms, n4 is the average number of moles of oxyalkylene added, and is a number from 1 to 200. 11A is an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms. 5 O is a divalent alkylene oxide group with 2 to 4 carbon atoms, n5 is the average number of added moles of alkylene oxide, ranging from 1 to 200, and r and s are integers satisfying the relationships 0 ≤ r ≤ 7, 1 ≤ s ≤ 8, and 2 ≤ r + s ≤ 8.

[0045] R in equations (1) to (4) 1 , R 2 , R 3 , R 5 , R 8 , R 9 , R 11 When each of these is an alkyl group having 1 to 30 carbon atoms, for example, it may be a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, heneicosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, or triacontyl group, and alkyl groups having 3 or more carbon atoms may be linear, branched, cyclic, or any combination thereof.

[0046] R in equations (1) to (4) 1 , R 2 , R 3 , R 5 , R 8 , R 9 , R 11When each of these is an alkenyl group having 2 to 30 carbon atoms, for example, it may be an ethenyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, eicocenyl group, heneicocenyl group, dococenyl group, tricocenyl group, tetracocenyl group, pentacocenyl group, hexacocenyl group, heptacocenyl group, octacocenyl group, nonacocenyl group, or triacontenyl group, and the alkenyl group having 3 or more carbon atoms may be linear, branched, cyclic, or any combination thereof.

[0047] A in equation (1), equation (2), or equation (4) 1 O, A 2 O, A 5 Each of the O groups is a divalent alkylene oxide group having 2 to 4 carbon atoms, specifically an ethylene oxide group, a propylene oxide group, and a butylene oxide group. When it is a propylene oxide group or a butylene oxide group, it may be linear, branched, or cyclic. If n1, n2, and n5 are each 2 or greater, (A 1 O) n1 , (A 2 O) n2 , (A 5 O) n5 Each of these may be a chain of one type of alkylene oxide group, or a chain of two or more types of alkylene oxide groups, and the chain of two or more types of alkylene oxide groups may have a block structure or a random structure.

[0048] OA in formula (3) or formula (4) 3 OA 4 Each of these is a divalent oxyalkylene group having 2 to 4 carbon atoms, specifically an oxyethylene group, an oxypropylene group, and an oxybutylene group, and when it is an oxypropylene group or an oxybutylene group, it may be linear, branched, or cyclic. If n3 and n4 are both 2 or greater, (OA3 ) n3 (OA) 4 ) n4 Each of these may be a chain of one type of oxyalkylene group, or a chain of two or more types of oxyalkylene groups, and the chain of two or more types of oxyalkylene groups may have a block structure or a random structure.

[0049] R in equation (2) 4 In this context, (k+m) valency polycarboxylic acids with 1 to 30 carbon atoms may be linear, branched, cyclic, or a combination thereof when they have 3 or more carbon atoms, and may contain unsaturated double bonds when they have 2 or more carbon atoms, and may have multiple carboxyl groups bonded to the same carbon atom. Since 2 ≤ k+m ≤ 6, (k+m) valency polycarboxylic acids with 1 to 30 carbon atoms are polycarboxylic acids having 2 to 6 carboxyl groups, and examples include aliphatic polycarboxylic acids (e.g., malonic acid, succinic acid, adipic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, glutaric acid, azelaic acid); aromatic polycarboxylic acids (e.g., terephthalic acid, isophthalic acid, orthophthalic acid, trimellitic acid, pyromellitic acid); and alicyclic polycarboxylic acids (e.g., cyclohexane-1,4-dicarboxylic acid). Among these, aliphatic polycarboxylic acids having 2 to 12 carbon atoms are preferred, and succinic acid, adipic acid, sebacic acid, maleic acid, or fumaric acid are more preferred.

[0050] R 4 Preferably, it is a hydrocarbon group with 1 to 30 carbon atoms and a (k+m) valency.

[0051] R in equation (3) 6In this context, polyhydric alcohols with 2 to 30 carbon atoms and a (p+q) valency may be linear, branched, cyclic, or a combination thereof when they have 3 or more carbon atoms, and may contain unsaturated double bonds when they have 2 or more carbon atoms, and may have multiple hydroxyl groups bonded to the same carbon atom. Since 2 ≤ p+q ≤ 8, polyhydric alcohols with 2 to 30 carbon atoms and a (p+q) valency are polyhydric alcohols having 2 to 8 hydroxyl groups, and examples include dihydric alcohols (e.g., ethylene glycol, diethylene glycol, propylene glycol, butanediol, neopentyl glycol, hexanediol); trihydric to pentahydric alcohols (e.g., glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitan, diglycerin); and sugars and their derivatives (e.g., sucrose, glucose, fructose, methyl glycoside). Among these, polyhydric alcohols or sugars with a 3- to 5-valent pH are preferred, and sorbitol, sorbitan, polyglycerin, pentaerythritol, dipentaerythritol, or sucrose are more preferred.

[0052] R 6 Preferably, the hydrocarbon group has 2 to 30 carbon atoms and a (p+q) valency, and this hydrocarbon group may contain an ether bond.

[0053] R in equation (4) 10In this context, polyhydric alcohols with 2 to 30 carbon atoms and a (r+s) valency may be linear, branched, cyclic, or a combination thereof when they have 3 or more carbon atoms, and may contain unsaturated double bonds when they have 2 or more carbon atoms, and may have multiple hydroxyl groups bonded to the same carbon atom. Since 2 ≤ r+s ≤ 8, polyhydric alcohols with 2 to 30 carbon atoms and a (r+s) valency are polyhydric alcohols having 2 to 8 hydroxyl groups, and examples include dihydric alcohols (e.g., ethylene glycol, diethylene glycol, propylene glycol, butanediol, neopentyl glycol, hexanediol); trihydric to pentahydric alcohols (e.g., glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitan, diglycerin); and sugars and their derivatives (e.g., sucrose, glucose, fructose, methyl glycoside). Among these, polyhydric alcohols or sugars with a 3- to 5-valent pH are preferred, and sorbitol, sorbitan, polyglycerin, pentaerythritol, dipentaerythritol, or sucrose are more preferred.

[0054] R 10 Preferably, the hydrocarbon group has 2 to 30 carbon atoms and a (r+s) valency, and this hydrocarbon group may contain an ether bond.

[0055] Examples of hydrocarbon groups with 1 to 30 carbon atoms and a (k+m) valency, hydrocarbon groups with 2 to 30 carbon atoms and a (p+q) valency, and hydrocarbon groups with 2 to 30 carbon atoms and a (r+s) valency include groups obtained by removing (k+m), (p+q), and (r+s) hydrogen atoms, respectively, from alkanes or alkenes with 1 to 30 carbon atoms. Examples of alkanes having 1 to 30 carbon atoms include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, heneicosane, docosane, tricosane, tetracosane, pentacosane, hexacosane, heptacosane, octacosane, nonacosane, and triacontane. Their structures can be linear, branched, cyclic, or combinations thereof. Examples of alkenes with 2 to 30 carbon atoms include ethene, propene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, octadecene, nonadecene, eicosene, heneicosene, docosene, tricosene, tetracosene, pentacosene, hexacosene, heptacosene, octacosene, nonacosene, and triaconthene. Their structures can be linear, branched, cyclic, or combinations thereof.

[0056] A preferred example of the chemical substance represented by formula (1) is given. R 1 This is an alkyl group having 1 to 18 carbon atoms (linear, branched, cyclic, or a combination thereof) or an alkenyl group having 2 to 18 carbon atoms (linear, branched, cyclic, or a combination thereof), R 2 is a hydrogen atom, an alkyl group with 1 to 24 carbon atoms (linear, branched, cyclic, or a combination thereof), an alkenyl group with 2 to 18 carbon atoms (linear, branched, cyclic, or a combination thereof), or -C(=O)-R 3 It is a base, R 3 This is an alkyl group having 1 to 18 carbon atoms (linear, branched, cyclic, or a combination thereof), A 1 O is an ethylene oxide group or a propylene oxide group, n1 is between 1 and 100 or between 1 and 50.

[0057] A preferred example of the chemical substance represented by equation (2) is given. R 4 is a residue obtained by removing (k + m) carboxy groups from a (k + m)-valent polycarboxylic acid having 2 to 10 carbon atoms, preferably a (k + m)-valent hydrocarbon group (linear, branched, cyclic, or a combination thereof) having 2 to 10 carbon atoms, k is 0 or 1, m is 1 or 2, R 5 is an alkyl group having 1 to 10 carbon atoms (linear, branched, cyclic, or a combination thereof), A 2 O is an ethylene oxide group or a propylene oxide group, n2 is 1 to 100 or 1 to 50.

[0058] Preferred examples of the chemical substance represented by formula (3) are given. R 6 is a residue obtained by removing (p + q) hydroxy groups from a (p + q)-valent polyalcohol having 2 to 10 carbon atoms, preferably a (p + q)-valent hydrocarbon group (linear, branched, cyclic, or a combination thereof. The hydrocarbon group may contain an ether bond) having 2 to 10 carbon atoms, p and q satisfy the relationship 1 ≦ p ≦ 4, 1 ≦ q ≦ 4, and 2 ≦ p + q ≦ 6, R 7 is a hydrogen atom, R 8 is an alkyl group having 1 to 18 carbon atoms (linear, branched, cyclic, or a combination thereof) or an alkenyl group having 2 to 18 carbon atoms (linear, branched, cyclic, or a combination thereof), preferably an alkyl group having 10 to 18 carbon atoms or an alkenyl group having 10 to 18 carbon atoms, OA 3 is an oxyethylene group or an oxypropylene group, n3 is 1 to 100, 1 to 80, or 5 to 80.

[0059] Preferred examples of the chemical substance represented by formula (4) are given. R 10is a residue obtained by removing (r + s) hydroxy groups from a polyhydric alcohol having (r + s) valences and 2 to 10 carbon atoms, preferably a (r + s) -valent hydrocarbon group having 2 to 10 carbon atoms (linear, branched, cyclic, or a combination thereof. The hydrocarbon group may contain an ether bond), r and s satisfy the relationship of 1 ≦ r ≦ 4, 1 ≦ s ≦ 4, and 2 ≦ r + s ≦ 6, R 11 is an alkyl group having 1 to 18 carbon atoms (linear, branched, cyclic, or a combination thereof) or an alkenyl group having 2 to 18 carbon atoms (linear, branched, cyclic, or a combination thereof), preferably an alkyl group having 10 to 18 carbon atoms or an alkenyl group having 10 to 18 carbon atoms, OA 4 is an oxyethylene group or an oxypropylene group, n4 is 1 to 100, 1 to 80, or 5 to 80, A 5 O is an ethylene oxide group or a propylene oxide group, n5 is 1 to 100, 1 to 80, or 5 to 80, n4 + n5 is 20 to 80.

[0060] Formula (5) R 12 O-(C2H4O) n -R 13

[0061] In formula (5), R 12 and R 13 are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 20. However, when 12 and R 13 are both hydrogen atoms, n is an integer of 2 to 20.

[0062] When R 12 in formula (5) is an alkyl group having 1 to 4 carbon atoms, it is a methyl group, an ethyl group, a propyl group, or a butyl group. When it is a propyl group or a butyl group, it may be linear, branched, or cyclic. R 12 is preferably a hydrogen atom or a methyl group.

[0063] R in equation (5) 13 When R is an alkyl group having 1 to 4 carbon atoms, it is a methyl group, an ethyl group, a propyl group, or a butyl group, and when it is a propyl group or a butyl group, it may be linear, branched, or cyclic. 13 It is preferable that this is a hydrogen atom or a methyl group.

[0064] In equation (5), n is preferably an integer between 1 and 15, and more preferably an integer between 1 and 10. 12 and R 13 When all of them are hydrogen atoms, n is preferably an integer between 2 and 15, and more preferably an integer between 2 and 10.

[0065] A preferred example of the chemical substance represented by formula (5) is given. R 12 is a hydrogen atom or a methyl group, R 13 is a hydrogen atom or a methyl group, n is an integer between 2 and 15 or an integer between 2 and 10.

[0066] [Other materials] The geopolymer compositions of this disclosure may contain chemical admixtures other than chemical admixtures having oxyalkylene groups. Examples of other chemical admixtures include various chemical admixtures conventionally used in geopolymer mortar or concrete or cement mortar or concrete.

[0067] The geopolymer compositions of this disclosure may contain reinforcing materials. Examples of reinforcing materials include metal fibers, carbon fibers, glass fibers, and basalt fibers.

[0068] <Method for producing geopolymer compositions> The geopolymer composition of this disclosure is obtained by mixing the materials described above. The mixing of the materials is carried out, for example, by kneading using a mixer.

[0069] The order in which materials are mixed when preparing a geopolymer composition is not limited. For example, the active filler and aggregate are mixed first, then an alkaline solution is added and kneaded, and then a chemical admixture is added and kneaded to obtain the geopolymer composition.

[0070] The mixing ratio of the active filler to the alkaline solution may be set appropriately depending on the type of active filler and the type and concentration of the alkaline solution. For example, the alkaline solution may be mixed in a mass ratio of 10 to 100 parts by mass of 100 parts by mass of active filler.

[0071] In the geopolymer composition of this disclosure, it is presumed that the components contained in the blast furnace slag fine aggregate exhibit similar reactivity to that of the active filler, and that the surface of the blast furnace slag fine aggregate becomes part of the geopolymer structure. Therefore, it is preferable to increase the amount of alkaline solution used as the mass ratio of blast furnace slag fine aggregate to the total fine aggregate increases.

[0072] <Geopolymer hardened material> The geopolymer cured body of this disclosure is obtained by curing the geopolymer composition of this disclosure. Specifically, the geopolymer composition is placed in a mold and cured to obtain the geopolymer cured body. The geopolymer composition placed in the mold may be subjected to treatment such as degassing in accordance with conventional methods. The geopolymer composition placed in the mold generally hardens to form a cured body by a condensation polymerization reaction accompanied by dehydration.

[0073] The curing temperature and curing time of the geopolymer cured product of this disclosure are not limited. Depending on the target mechanical strength of the geopolymer cured product, curing methods such as heat curing, steam curing, autoclave curing, underwater curing, air curing, room temperature curing, sealed curing, or combinations thereof may be used. [Examples]

[0074] The geopolymer compositions and geopolymer cured products of this disclosure will be described in detail below with reference to examples. The geopolymer compositions and geopolymer cured products of this disclosure are not limited to the following examples.

[0075] [material] The following materials were prepared for the geopolymer composition. (1) Active filler • Blast furnace slag fine powder (BFS): Density 2.91 g / cm³ 3 , powder degree 4220cm 2 / g • Fly ash (FA): Density 2.28 g / cm³ 3 , powder degree 3670cm 2 / g (2) Alkaline solution • Sodium silicate solution (WG): Sodium silicate No. 2, density 1.50 g / cm³ 3 • Sodium hydroxide aqueous solution (NH): molar concentration 10 mol / l, density 1.33 g / cm³ 3 • Water (W): Tap water (3) Fine aggregate • Blast furnace slag fine aggregate (BFSS): Absolute dry density 2.76 g / cm³ 3 , water absorption rate 0.58% ·Standard sand (SS): Absolute dry density 2.64g / cm 3 , water absorption rate 0.42% (4) Chemical admixtures containing oxyalkylene groups (CA): Polyether compounds, the main compound being HO-(CH2CH2O)9-H, weight-average molecular weight 400, density 0.93 g / cm³ 3 Toho Chemical Industry Co., Ltd.

[0076] [Preparation of geopolymer compositions] Geopolymer mortar was produced as a geopolymer composition. The materials were prepared as shown in Table 1, and then CA was added at the addition rate (mass%) shown in Table 2. The mixture was then kneaded in a mortar mixer for 3 minutes to prepare a geopolymer composition. CA was added as an external allocation based on the mass % of the amount of active filler (total amount of BFS and FA).

[0077] [Table 1]

[0078] [Evaluation of hardened geopolymer materials] (1) Neutralization depth A 40mm x 40mm x 160mm test specimen was sealed and cured at 20±2°C for 4 weeks. After demolding, it was stored for 4 weeks in an environment of 20±2°C and 60±5% humidity. Subsequently, it was stored in an environment of 20±2°C, 60±5% humidity, and 5±0.2% carbon dioxide concentration. The carbonation depth (mm) was measured according to JIS A1152:2018. Due to the dimensions of the test specimen, the maximum carbonation depth was 20mm. The measurement results are shown in Table 2.

[0079] (2) Compressive strength Test specimens were prepared using a mold measuring 50 mm in diameter and 100 mm in length, and then sealed and cured at a temperature of 20 ± 2°C until the specified age. Compression tests were conducted in accordance with JIS A1108:2018 at 1 week and 4 weeks of age. The test results are shown in Table 2.

[0080] [Table 2]

[0081] In the example where the fine aggregate is blast furnace slag fine aggregate and contains a chemical admixture having an oxyalkylene group, it was found that the carbonation rate was slow and the compressive strength was high.

[0082] In comparisons of Examples 1-3 and Comparative Examples 3-5, it can be seen that the higher the content of the chemical admixture containing oxyalkylene groups, the slower the neutralization rate, and the lower the content of the chemical admixture containing oxyalkylene groups, the higher the compressive strength.

Claims

1. an active filler, a base, and water; Blast furnace slag fine aggregate, at least one selected from the group consisting of an ester compound having an oxyalkylene group, an ether compound having an oxyalkylene group, and a glycol compound having an oxyalkylene group; 1. A geopolymer composition comprising:

2. The total content of the ester-based compound having an oxyalkylene group, the ether-based compound having an oxyalkylene group, and the glycol-based compound having an oxyalkylene group is 0.5% by mass to 5% by mass relative to the total amount of the active filler. The geopolymer composition according to claim 1.

3. 3. The geopolymer composition of claim 1 or claim 2, wherein the active filler comprises at least one of fly ash and ground granulated blast furnace slag.

4. A hardened geopolymer body which is a hardened product of the geopolymer composition according to any one of claims 1 to 3.