Gap-filling material and gap-filling geopolymer hardened body using the same

Abstract

To provide a gap-filling material with which a geopolymer that can replace Portland cement and that reuses industrial waste such as ground granulated blast furnace slag can achieve sufficient high strength even when cured at room temperature under not-so-strong alkaline conditions, and which has required workability regarding fluidity and setting time as well as a reasonable formulation technology.SOLUTION: A gap-filling material comprises: a powder that is a high-reactivity active powder consisting of metakaolin and / or ground granulated blast furnace slag, or a mixed powder of the high-reactivity active powder and a low-activity or inactive powder consisting of fly ash, stone powder, and / or slowly air-cooled blast furnace slag powder; and an alkaline aqueous solution containing sodium metasilicate and / or sodium silicate, or sodium metasilicate and / or sodium silicate and a hydroxide of an alkali metal, or an alkaline aqueous solution containing a carbonate of an alkali metal or a carbonate of an alkali metal and a hydroxide of an alkali metal. The gap-filling material forms a geopolymer in a room-temperature environment by appropriate selection and combination of the type or composition of the powder and the alkaline agent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a gap filling material that uses a geopolymer that is low in carbon and has excellent adhesion to steel materials, acid resistance, fire resistance, and alkali-aggregate reaction resistance, and to a hardened geopolymer for gap filling that uses the same. [Background technology]

[0002] In the construction of new buildings and civil engineering structures, as well as in their reinforcement work, pastes and mortars using Portland cement (PC) are generally used as adhesives to fix and secure anchors such as screw bolts and deformed reinforcing bars in concrete in post-installed anchor construction methods, as fillers to fill cavities behind the lining concrete in tunnel construction, and as grout fillers for the sheath of prestressed concrete manufactured using the post-tensioning method. Anchor adhesives and grout fillers for prestressed concrete generally require high strength. In particular, anchor adhesives must have a strength of at least 80N / mm 2 It must have a compressive strength of at least

[0003] However, when Portland cement clinker is made using raw materials such as limestone and fired at high temperatures, it requires many heat sources such as coal and waste plastic, and the limestone decomposes, generating large amounts of CO2. For this reason, CO2 emissions from the cement industry are said to account for 30% of all construction materials, and about 5% of Japan's total.

[0004] Therefore, in order to achieve carbon neutrality as a countermeasure against global warming, low-carbon binders such as geopolymers have been actively developed as alternatives to Portland cement. Geopolymers do not use cement clinker like Portland cement. Instead, they are inorganic materials that harden through a condensation polymerization reaction of a mixture of amorphous powders (active fillers) containing silicon and aluminum, such as industrial waste materials like granulated blast furnace slag, fly ash, and metakaolin, with an aqueous solution of at least one alkaline substance, such as an alkali metal silicate, carbonate, or hydroxide (hereinafter sometimes referred to as an alkaline solution or hardening liquid). Such geopolymers are environmentally friendly because they do not use cement clinker, which emits large amounts of carbon dioxide, and can reuse industrial waste.

[0005] In recent years, it has become clear that geopolymers can be produced even when some active fillers are replaced with crystalline powders (inert fillers), such as slowly cooled blast furnace slag powder, fluidized bed coal ash, and crushed stone powder. Geopolymer technology using a mixture of active and inert fillers has opened up new avenues for the high-value-added reuse of inert waste.

[0006] When using only granulated blast furnace slag powder or metakaolin as a geopolymer filler, the hardened geopolymer has high strength, but the setting time, which is a key indicator of workability, is short, and there is a risk of the material hardening before construction is complete. Considering typical construction and civil engineering practices, the initial setting time for geopolymer materials is at least 30 minutes. Adding fly ash or an inert filler with low reactivity reduces strength but increases setting time. Geopolymer strength and setting time depend not only on the active filler mixture ratio but also on the alkaline solution. Generally, the more reactive the filler, the higher the strength and shorter the setting time of the geopolymer. Furthermore, the higher the ambient temperature, the shorter the setting time. The hardened strength at room temperature is lower than that achieved with heat curing above 40°C.

[0007] Fluidity is also an important indicator of workability. When filling geopolymer materials into gaps, their fluidity must be particularly high. Increasing the liquid-powder ratio increases fluidity, but this can result in a decrease in strength. While the strength of the geopolymer after hardening is obviously important, its workability is also important. Therefore, achieving both workability and strength is a key issue for realizing the practical application of geopolymers.

[0008] There has been much research around the world into the manufacturing methods and performance of geopolymers, including geopolymers using granulated blast furnace slag and fly ash as activated fillers. However, the know-how required to give geopolymers both the appropriate setting time, fluidity, and high strength has not yet been clearly established. Furthermore, the technology for properly selecting and combining activated fillers and alkaline solutions has not yet been established.

[0009] Patent Document 1 discloses a method for solidifying inactive low-calcium fluidized-bed coal ash, in which low-calcium fluidized-bed coal ash is added to an active filler and an alkaline solution, kneaded, and cured to solidify. Examples of active fillers include blast furnace slag powder, fly ash, high-calcium fluidized-bed coal ash (with a CaO content of over 10% by mass), molten slag powder from municipal waste incineration ash, metakaolin, and molten slag powder from sewage sludge incineration ash. While Patent Document 1 is a representative example of producing a geopolymer using an active filler and an inactive filler, it does not demonstrate the strength of the material cured at room temperature, nor does it propose a formulation for high-strength material cured at elevated temperatures.

[0010] In addition, Patent Document 2 relates to a geopolymer made of granulated blast furnace slag powder and inert crushed stone powder as fillers, but the amount of fine aggregate in the geopolymer is more than twice the powder mass. It does not mention the setting characteristics when there is less fine aggregate, i.e., when there is a lot of geopolymer matrix, and it ... 2 It was less than.

[0011] Conventional geopolymers are made using metakaolin, granulated blast furnace slag, and fly ash as active ingredients (S1 4+ ,Al 3+ ,Ca 2+In order to increase the dissolution rate of silicates (e.g., sodium silicate or potassium silicate) and the reactivity of the silicate, a large amount of strong alkaline NaOH or KOH is mixed. There are safety concerns regarding the manufacturing and construction of geopolymers using strong alkaline aqueous solutions.

[0012] Because gypsum enhances the hydraulic potential of granulated blast furnace slag powder, gypsum-containing granulated blast furnace slag powder is commonly used as an admixture for Portland cement (PC) concrete. However, because gypsum reacts with silicates, shortening the setting time of the geopolymer, gypsum-free granulated blast furnace slag powder is commonly used to prepare geopolymers. As a result, without the use of gypsum, the activation of granulated blast furnace slag powder relies on a stronger alkaline solution. Therefore, in order to achieve both setting time and strength, it is also important to consider how to design geopolymer mixes when using gypsum-containing granulated blast furnace slag powder. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-113730 [Patent Document 2] Patent No. 7041918 Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention has been made to solve the above-mentioned problems, and aims to provide a gap filler that can replace Portland cement through rational blending technology, and that can achieve sufficiently high strength even when cured at room temperature under moderately alkaline conditions using geopolymers made from recycled industrial waste such as blast furnace slag powder, and that has the required workability, such as fluidity and setting time, and a hardened geopolymer for gap filling using the same. [Means for solving the problem]

[0015] The gap filler of the present invention, which has been made to solve the above problems and achieve the above objects, comprises a powder which is at least one type of highly reactive activated powder selected from metakaolin and ground granulated blast furnace slag, or a mixed powder of the highly reactive activated powder and at least one type of low-activity or inactive powder selected from fly ash, stone powder, and slowly cooled ground granulated blast furnace slag; and an alkaline aqueous solution containing at least one of sodium metasilicate and sodium silicate, or at least one of sodium metasilicate and sodium silicate and an alkali metal hydroxide, or containing an alkali metal carbonate or an alkali metal carbonate and an alkali metal hydroxide, It is characterized by being designed to form geopolymers in room temperature environments.

[0016] This gap filling material is at least one selected from, for example, a post-installed anchor element fixing material, a grout material for post-tensioning, a backfill material for buildings, a filling material for cavities in the ground, and a crack repair material.

[0017] In this gap filling material, the stone powder is, for example, crushed stone powder, or powder of at least one rock selected from limestone and siliceous rocks such as sandstone and slate.

[0018] In this gap filling material, the powder may contain at least one selected from the metakaolin and the ground granulated blast furnace slag, or may contain at least one selected from the metakaolin and the ground granulated blast furnace slag, and at least one selected from the fly ash and the stone powder.

[0019] It is preferable that the powder of this gap filler is made of the ground granulated blast furnace slag, or the ground granulated blast furnace slag and 60% or less of the fly ash and / or stone powder.

[0020] This gap filling material may be the ground granulated blast furnace slag containing or having gypsum added thereto, or may be gypsum-free.

[0021] More specifically, the gap filler is a gap filler in which the alkali metal in the alkaline aqueous solution is sodium, The powder is made of the metakaolin or made of the metakaolin and the stone powder and / or the fly ash, and in the alkaline aqueous solution, the molar ratio of silicon (Si) to sodium (Na) (Si / Na) is 0.853 to 1.097, the molar ratio of sodium to water (H2O) (Na / H2O) is 0.143 to 0.151, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.2, or the powder comprises the ground granulated blast furnace slag and the fly ash, and in the alkaline aqueous solution, the molar ratio of silicon to sodium (Si / Na) is 1.097 to 1.324, and the molar ratio of sodium to water (Na / H2O) is 0.103 to 0.143, preferably 0.139 to 0.143, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0; or the powder comprises the ground granulated blast furnace slag and the stone powder, and in the alkaline aqueous solution, the molar ratio of silicon to sodium (Si / Na) is 0.853 to 1.324, and the molar ratio of sodium to water (Na / H2O) is 0.106 to 0.151, preferably 0.106 to less than 0.143, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0; or The powder is made of the granulated blast furnace slag powder containing or not containing gypsum, and in the alkaline aqueous solution, the molar ratio of silicon to sodium is 1.163 to 1.324, the molar ratio of sodium to water is 0.135 to 0.140, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0; or The powder comprises the blast furnace slag powder, which may or may not contain gypsum, and at least one of the fly ash and the stone powder, to which a setting retarder is added, and in the alkaline aqueous solution, the molar ratio of silicon to sodium is 0.853 to 1.097, the molar ratio of sodium to water is 0.143 to 0.151, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0.

[0022] This gap filler may be obtained by adding the sodium metasilicate or the carbonate of the alkali metal as an alkali powder in a mass ratio of 5 to 20% of the powder to the activated powder or the mixed powder of the activated powder and the low-activity or inactive powder, and may further be mixed with water or a mixed aqueous solution of the hydroxide of the alkali metal having a concentration of 1 mol / L or more.

[0023] The gap filler may be blended with set retarders, surfactants, shrinkage reducing agents, and / or fiber fabrics or fibers.

[0024] The gap filler may include coarse and / or fine aggregates.

[0025] The gap-filling geopolymer hardened body of the present invention, which has been made to solve the above problems and achieve the above objects, is characterized in that it is the gap-filling material that forms the geopolymer in a room temperature environment. [Effects of the Invention]

[0026] The gap filler and hardened geopolymer gap filler of the present invention utilize industrial waste materials, such as blast furnace slag powder, to produce the geopolymer. Compared to conventional pastes and mortars using Portland cement, CO2 emissions can be reduced by up to 80%, resulting in significantly lower CO2 emissions. Furthermore, by optimizing the alkaline solution composition and its combination with powder, the use of an alkaline aqueous solution is eliminated, eliminating the need for a strong alkaline solution containing large amounts of alkali metal hydroxides, such as NaOH. This allows for easy and safe preparation and use at construction sites, even in locations with a safety environment such as a factory. Furthermore, the material achieves the required setting time for construction work without requiring high-temperature curing above 40°C; sufficient strength can be achieved simply by curing at room temperature.

[0027] The obtained hardened geopolymer for gap filling has superior adhesion to steel materials, and resistance to acid, fire, and alkali-aggregate reaction (ASR) compared to hardened Portland cement. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments for carrying out the present invention will be described in detail, but the scope of the present invention is not limited to these embodiments.

[0029] The gap filling material of the present invention comprises at least a powder which is a filler or a powder, an alkaline aqueous solution, and a fine aggregate.

[0030] The powder is at least one selected from the group consisting of metakaolin, ground granulated and slowly cooled blast furnace slag, fly ash, and stone powder, and the alkaline aqueous solution contains at least one of sodium metasilicate and sodium silicate, or at least one of sodium metasilicate and sodium silicate and an alkali metal hydroxide, or an alkaline metal carbonate, or an alkaline metal carbonate and an alkali metal hydroxide. In particular, it is preferable that the alkali metal in the alkaline aqueous solution is sodium.

[0031] Among the powders, metakaolin is an amorphous material obtained by calcining kaolin at a temperature of around 750°C, and is expressed by the chemical formula Al2Si2O7, for example. When exposed to alkaline stimulation, it can harden by producing a condensation polymer of aluminosilicate, which has a structure similar to that of natural zeolite.

[0032] Metakaolin has a specific surface area (Blaine value) of 2000 cm 2 / g or more. The finer the powder, the better the strength expression, so the Blaine value is 4000 cm 2 / g or more is more preferable.

[0033] Blast furnace slag is a by-product of steelworks, an industrial waste product of steelworks blast furnaces. It can be broadly divided into granulated blast furnace slag and air-cooled blast furnace slag. Granulated blast furnace slag powder is an amorphous, active filler produced by blasting molten slag discharged from steelworks blast furnaces with large amounts of water and air at high speed and pressure, rapidly cooling it, and then finely grinding it. It has a network structure with gaps in the -Si-O- structure, and in alkaline aqueous solutions, OH atoms can easily penetrate, destroying the network structure and initiating a hydration reaction, which allows it to harden. However, air-cooled blast furnace slag powder is produced by pouring molten slag discharged from steelworks blast furnaces into a cooling yard and gradually cooling it with natural cooling and moderate water spraying. This crystalline, rock-like slag is then finely ground, and it is classified as an inert powder with extremely low reactivity in alkaline solutions.

[0034] Granulated blast furnace slag powder is specified as 3000, 4000, 6000, and 8000 by the JIS standard (JIS A 6206 Granulated blast furnace slag powder for concrete). Granulated blast furnace slag powder 3000 has a specific surface area of ​​2750 cm 2 / g or more 3500cm 2 / g, and the specific surface area of ​​4000 is 3500 cm 2 / g or more 5000cm 2 / g, and the specific surface area of ​​6000 is 5000 cm 2 / g or more 600cm2 / g, and the specific surface area of ​​8000 is 7000 cm 2 / g or more 10000cm 2 / g. Either can be used, but the finer the particles, the higher the strength development but the faster they set. Therefore, when considering the balance between hardening time and strength after hardening, it is preferable to use 4000.

[0035] The ground granulated blast furnace slag may not contain gypsum, but gypsum may be mixed in advance, or gypsum may be added when preparing the gap filler, in which case the mass ratio of the ground granulated blast furnace slag to gypsum is, for example, 0.01 to 0.1, preferably 0.03 to 0.07.

[0036] Fly ash is a by-product emitted from coal-fired power plants, and is collected by electrically adsorbing the ash that melts during coal combustion and cools to form spherical particles. The main chemical components of fly ash are silicon dioxide (SiO2) and aluminum oxide (Al2O3), which account for 70-80%, with other components being ferric oxide (Fe2O3), calcium oxide (CaO), and magnesium oxide (MgO). Fly ash is classified into types I to IV according to the JIS standard (JIS A 6201 Fly Ash for Concrete). Type I fly ash has a 45μm sieve residue (wire sieve method) of 10% or less and a specific surface area (Blaine method) of 5000cm. 2 / g or more, and the flow value ratio is 105% or more. Fly ash type II is also a sieve residue of 40% or less, and a specific surface area of ​​2500 cm 2 / g or more, and the flow value ratio is 95% or more. Fly ash type III is also a sieve residue of 40% or less, and a specific surface area of ​​2500 cm 2 / g or more, and the flow value ratio is 85% or more. Fly ash type IV is also a sieve residue of 70% or less, and a specific surface area of ​​1500 cm 2 / g or more and a flow value ratio of 75% or more. Any standard fly ash may be used, and among them, it is preferable to use type I or type II in consideration of reactivity.

[0037] The stone powder may be crushed stone powder classified and discharged during the production of crushed stone, or may be powder obtained by crushing at least one rock selected from limestone and siliceous rocks such as sandstone or slate. Examples of stone powder include Calfinder (a trade name manufactured by Omi Mining Co., Ltd.), which is made by crushing and pulverizing amorphous limestone. The stone powder is a powder of 1500 cm 2 It is preferable that the fineness of the sand be 0.075 mm or less, and the maximum particle size be 0.075 mm or less. If the sand is coarser than this, it falls into the category of crushed sand, and it becomes difficult to form a geopolymer with good performance.

[0038] Such powder preferably contains metakaolin and / or ground granulated blast furnace slag, or preferably contains metakaolin and / or the ground granulated blast furnace slag, and the fly ash and / or stone powder.

[0039] The alkaline aqueous solution may be an aqueous solution containing, as the alkaline component, either sodium metasilicate (Na2SiO3: sodium metasilicate, or Na4SiO4: sodium orthosilicate, powder form) or sodium silicate (generally expressed by the composition formula Na2O·nSiO2·mH2O, where the coefficient n indicates the molar ratio of SiO2 / Na2O; liquid or gel form; also known as sodium silicate or water glass), or a mixture thereof; an aqueous solution containing at least one of sodium metasilicate and sodium silicate and an alkali metal hydroxide; or an alkaline aqueous solution containing an alkali metal carbonate or an alkali metal carbonate and an alkali metal hydroxide.

[0040] There are several types of sodium silicate depending on the SiO2 / Na2O molar ratio n. Any sodium silicate with n in the range of 2.0 to 4.0 can be used. Preferably, the molar ratio n is 2.0 to 3.0 (JIS No. 1 and No. 2 water glass).

[0041] Examples of such alkali metal hydroxides include sodium hydroxide (caustic soda) and potassium hydroxide, and examples of alkali metal carbonates include sodium carbonate and potassium carbonate. Among these, the alkali metal in the alkali metal hydroxide or alkali metal carbonate in the alkaline aqueous solution is preferably sodium.

[0042] These alkaline aqueous solutions preferably have the Si / Na molar ratio and Na / H2O molar ratio described above, with the sodium silicate and sodium hydroxide mixture ratio adjusted according to the powder used. The mass concentration of sodium hydroxide in these alkaline aqueous solutions is reduced from 20-50% in conventional geopolymers to 10% or less (5% or less when the WG:NH ratio is 18:1 or less). This is not as strong as a deleterious substance (corrosive to the skin, serious eye damage, or similar irritation). Therefore, under relatively mild alkaline conditions, these solutions can be handled relatively safely as gap fillers and used to form hardened geopolymer gap-filling bodies.

[0043] By using this gap filling material, there is no need to prepare the gap filling material in a safe environment such as a factory where strong alkaline conditions can be used, and to manufacture a hardened geopolymer for gap filling.The gap filling material can be prepared and filled into gaps at the gap filling construction site, which not only makes it safer, but also improves construction efficiency and contributes to an improved working environment.

[0044] Furthermore, since this gap filler is made by appropriately mixing powder and an alkaline aqueous solution, it can form a geopolymer by curing it at room temperature, for example, 0 to 40°C, preferably 5 to 35°C, without having to be heated and cured.

[0045] A preferred condition for the powder and alkaline aqueous solution in this gap filling material is, for example, that the alkali metal in the alkali metal hydroxide or alkali metal carbonate in the alkaline aqueous solution is sodium. More specifically, when the powder is made of metakaolin or metakaolin and stone powder or fly ash, the molar ratio of silicon to sodium in the alkaline aqueous solution is 0.853 to 1.097 by appropriately mixing at least one of sodium metasilicate and sodium silicate with the sodium hydroxide, the molar ratio of sodium to water is 0.143 to 0.151, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.2, more preferably 0.8 to 1.1.

[0046] Another preferred condition for the powder and alkaline aqueous solution in this gap filling material is, for example, when the powder consists of ground blast furnace slag and fly ash, the molar ratio of silicon to sodium in the alkaline aqueous solution is 1.097 to 1.324 by appropriately mixing at least one of sodium metasilicate and sodium silicate with sodium hydroxide, and the molar ratio of sodium to water is 0.103 to 0.143, preferably 0.139 to 0.143, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0, more preferably 0.5 to 0.6.

[0047] Another preferred condition for the powder and alkaline aqueous solution in this gap filler is that when the powder consists of ground blast furnace slag and stone powder, the molar ratio of silicon to sodium in the alkaline aqueous solution is 0.853 to 1.324 by appropriately mixing at least one of sodium metasilicate and sodium silicate with sodium hydroxide, and the molar ratio of sodium to water is 0.106 to 0.151, preferably less than 0.106 to 0.143, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0, more preferably 0.5 to 0.6.

[0048] Another preferred condition for the powder and alkaline aqueous solution in this gap filling material is that the powder is made of the blast furnace slag powder containing or not containing gypsum, and in the alkaline aqueous solution, at least one of the sodium metasilicate and the sodium silicate is appropriately mixed with the sodium hydroxide to make the molar ratio of silicon to sodium 1.163 to 1.324, the molar ratio of sodium to water is 0.135 to 0.140, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0, more preferably 0.5 to 0.6.

[0049] Another preferred condition for the powder and alkaline aqueous solution in this gap filling material is that the powder consists of blast furnace slag powder, which may or may not contain gypsum, and at least one of fly ash and stone powder, and contains a setting retarder whose main component is a tartrate or the like, the alkaline aqueous solution contains an appropriate blend of at least one of sodium metasilicate and sodium silicate and sodium hydroxide to give a molar ratio of silicon to sodium of 0.853 to 1.097, the molar ratio of sodium to water is 0.143 to 0.151, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0, more preferably 0.5 to 0.6.

[0050] In this gap filler, sodium metasilicate or an alkali metal carbonate is contained in an amount of 5 to 20% by mass of the powder, and is added to an active powder or a mixed powder of an active powder and a low-activity or inactive powder, and the above composition may be further mixed with water or a mixed aqueous solution of the alkali metal hydroxide having a concentration of 1 mol / L or more.

[0051] This gap filler is useful as a fixing material for post-installed anchor elements, a grout material for post-tensioning, a backfill material for buildings, and a filling material for cavities in the ground, and is also useful as a crack repair material if no coarse or fine aggregate for concrete is added.

[0052] Use of this gap filler eliminates the need for the troublesome process of heating and curing the filled areas at construction sites where post-installed anchor elements are fixed, post-tensioning grout is filled, building backfilling is performed, and cavities in the ground are filled, which contributes to improving productivity and work efficiency, reducing manufacturing costs, and saving energy.

[0053] Gap-filling geopolymer hardened bodies made with this gap filler are less susceptible to deterioration than Portland cement concrete, even in acidic environments. As a result, they are highly durable against acid rain and other conditions. Furthermore, such hardened geopolymer bodies show less deterioration in performance during fires than Portland cement concrete, and are also superior in heat and fire resistance.

[0054] Furthermore, even if Portland cement concrete uses alkali-aggregate-reactive aggregate, the hardened geopolymer gap filler made with this gap filler will not deteriorate because the geopolymer that comes into contact with the concrete will not undergo alkali-silica reaction (ASR), a type of alkali-aggregate reaction in which minerals in the aggregate react with alkaline components, causing deterioration. Furthermore, because it does not contain calcium hydroxide, a Portland cement hydrate, it will not produce the efflorescence that occurs in Portland cement mortar, where calcium hydroxide dissolves in rainwater and reacts with carbon dioxide in the air to produce calcium carbonate.

[0055] The hardened geopolymer gap-filling material obtained by the technology of this invention has high adhesive strength with steel materials. Although the mechanism is unclear, it is suitable for fixing post-installed anchor elements using steel materials and for filling grout for post-tensioning.

[0056] Generally, in the civil engineering field, the compressive strength is 60N / mm 2 Concrete with a compressive strength of over 60N / mm is called high-strength concrete. 2When the strength exceeds this, it is called ultra-high strength concrete. When the hardened geopolymer gap filling material using this gap filling material is used as a post-installed anchor element fixing material or a grout material for post-tensioning, especially when used as a post-installed anchor element fixing material, it is required to be able to harden in a room temperature environment, to ensure sufficient usable time, i.e., construction time, and to have extremely excellent strength development. For example, considering the situation at a construction site for post-installed anchor element fixing, the hardened geopolymer gap filling material using this gap filling material has a compressive strength of 80 N / mm at 28 days of age. 2 As mentioned above, the initial setting time must be 30 minutes or more, and this requirement is met.

[0057] If existing fillers such as ground granulated blast furnace slag, metakaolin, fly ash, and / or stone powder are used as gap fillers, and in particular ground granulated blast furnace slag and / or metakaolin, and fly ash and / or stone powder are selected and used, the strength development of the geopolymer at room temperature will be excellent, and the hardened body will have high strength. Ground granulated blast furnace slag is a by-product of steel production and is an industrial waste, fly ash is a by-product of power generation at coal-fired power plants and is also an industrial waste, and stone powder is a waste product from the production of crushed stone and crushed sand, so using them as powders is environmentally friendly and is preferable from the perspective of recycling industrial waste.

[0058] Furthermore, by incorporating or adding gypsum to ground granulated blast furnace slag powder to form a gap filler containing calcium-rich ground granulated blast furnace slag powder in the powder, it is possible to easily and simply prepare a high-strength or ultra-high-strength hardened geopolymer gap filler. The weight ratio of ground granulated blast furnace slag powder to the powder may be 0.3 to 1.0, but from the perspective of achieving high or ultra-high strength, a ratio of 0.6 to 1.0 is preferred.

[0059] However, by increasing the amount and fineness of the granulated blast furnace slag powder used in the gap filling material, the hardened geopolymer gap filling material formed using it has excellent strength, but it hardens quickly and may not have a sufficient usable time for construction work. However, the setting time of such gap fillers depends not only on the type, quality, and mixing ratio of the powders used, as mentioned above, but also on the addition ratio of the alkaline powder (sodium metasilicate powder or alkali metal carbonate powder), and the type and concentration of the alkaline aqueous solution (setting liquid). If an alkaline solution or alkaline powder characterized by the above-mentioned numerical limitations (Si / Na ratio, Na / H2O ratio, sodium metasilicate addition ratio, sodium carbonate addition ratio) is used, a sufficient usable time can be achieved.

[0060] On the other hand, a setting retarder may be added to increase the usable life of the gap filler. However, in this case, the strength of the gap filler after room temperature curing may be lower than the strength after curing without the setting retarder, although this is not always the case. The required strength can be achieved by adjusting the mixing ratio of the active filler and the composition of the alkaline solution.

[0061] To achieve a good balance of the following characteristics for a gap-filling geopolymer hardened body, it must be able to be formed by curing in a room temperature environment, achieve sufficient strength to withstand practical use, have appropriate setting characteristics so that it does not begin setting during normal work by the worker but begins setting about 30 minutes after the work is finished, and have sufficient fluidity for filling, it is important to optimize the type of powder, the composition of the alkaline aqueous solution, and their quantitative ratios.

[0062] In order to prevent the gap filler from coagulating into a geopolymer during the gap filling process, the setting time is delayed and extended so that it does not coagulate for more than about 30 minutes from the time of mixing the powder with the alkaline aqueous solution, ensuring sufficient working time. In addition to the tartrate salts listed above, hydroxycarboxylic acids such as citric acid, gluconic acid, malic acid, salicylic acid, m-hydroxybenzoic acid, and p-hydroxybenzoic acid, as well as their salts, inorganic carbonates, lignosulfonic acid, or their salts may also be added to the gap filler. These may be mixed in an amount of 0.1 to 10% by mass of the powder in the gap filler. In the case of tartrate salts, a 5.0% mass mixture of the powder is preferred. If necessary, a shrinkage reducing agent containing a polyester polymer or a polyether polymer, which is an organic chemical admixture that reduces shrinkage due to drying during curing and prevents cracking, may be mixed into the gap filler in an amount of 0.1 to 5.0 mass % of the powder. And / or, to prevent cracking, improve strength, prevent explosion, etc., 0.1 to 10 mass % of fiber fabric or fiber made from a fiber raw material such as steel fiber, glass fiber, polypropylene fiber, carbon fiber, aramid fiber, polyolefin fiber, vinylon fiber, and cellulose fiber may be mixed into the gap filler. And / or, 0.25 to 2.0 mass % of the powder may be added as an (AE) water-reducing agent, a high-performance (AE) water-reducing agent, or a fluidizing agent containing a polycarboxylic acid, alkyl aryl sulfonate, or melamine sulfonate as a component.

[0063] The gap filler is manufactured as follows. Powders containing at least one selected from metakaolin having a predetermined particle size, ground granulated blast furnace slag, fly ash, ground slowly cooled blast furnace slag, and stone powder are mixed until homogeneous. On the other hand, an alkaline aqueous solution containing at least one of sodium metasilicate and sodium silicate, or at least one of sodium metasilicate and sodium silicate and an alkali metal hydroxide, such as sodium hydroxide, or an alkali metal carbonate, such as sodium carbonate, or an alkali metal carbonate and an alkali metal hydroxide, such as sodium hydroxide, dissolved in water to a predetermined concentration is prepared to form a homogeneous solution.

[0064] The gap filler is used to prepare a hardened gap-filling geopolymer body, which is used as follows: The specified amounts of powder and aggregate, such as sand, are weighed out and thoroughly mixed to form a uniform mixture. The alkaline aqueous solution required for pouring the gap filler is then weighed out and added to the powder-aggregate mixture, followed by kneading. The mixture is then filled / molded into a gap or formwork and cured at room temperature for a specified period, such as 7 to 28 days, preferably 28 days (approximately one month), to obtain a hardened geopolymer gap filler.

[0065] The detailed procedures for preparing such hardened geopolymers for gap filling vary depending on the application.

[0066] For example, when using the gap filler as a fixing material for post-installed anchor elements, a vertical hole is drilled into the building to which the gap filler will be post-installed, and a predetermined amount of powder from the gap filler and aggregate such as sand are thoroughly stirred and mixed uniformly in advance to form a powder-aggregate mixture, to which a predetermined amount of alkaline aqueous solution is added for pouring the gap filler into.If the mixture is sufficiently mixed, it is left as is, but if it is not, it is mixed before being poured into the vertical hole, and anchor elements are hammered into the mixture to pierce and fix it, and then cured at room temperature to obtain a hardened geopolymer gap filler body with the anchor elements fixed in place. Alternatively, a predetermined amount of powder and aggregate mixture is wrapped in paper or the like to form a columnar capsule, and the capsule is then inserted into a vertical hole, after which a predetermined amount of alkaline aqueous solution is poured in, or the capsule is immersed in an alkaline aqueous solution and allowed to penetrate by a predetermined amount, and the capsule is then inserted into the vertical hole, and anchor elements are hammered in and pierced to fix them, and the mixture is cured at room temperature to obtain a hardened geopolymer for gap filling with the anchor elements fixed in place.

[0067] When using the gap filler as a grout for post-tensioning, first assemble the rebars and attach a sheath so that it penetrates the gaps between the rebars; before pouring the concrete, install the rebars and sheath, pour the concrete, and then insert post-tensioning steel into the sheath; after the concrete has hardened, set anchors / jacks on both ends of the post-tensioning steel to tension it; while it is still tensioned, inject the gap filler as grout into the sheath, fix it in place, and cure at room temperature to obtain a hardened geopolymer gap-filling body with the post-tensioning steel tightened.

[0068] When the gap filling material is used as a backfill material for buildings and a filler for cavities in the ground, a predetermined amount of the powder of the gap filling material, an alkaline aqueous solution, and a predetermined amount of aggregate are thoroughly stirred in advance at the time of use to mix uniformly, and the mixture is filled into gaps such as backfill cavities in buildings or cavities in the ground to be filled, and then cured at room temperature to obtain a hardened geopolymer for gap filling. [Example]

[0069] Examples and reference examples to which the present invention is applied will be described in detail below.

[0070] The raw materials used in the Examples and Reference Examples and their physical properties are shown in the following Table 1. The abbreviations for each raw material in Tables 2 to 7 are also listed.

[0071] The raw materials for the gap filling material were powders (abbreviated as P in the table): ground granulated blast furnace slag with gypsum (BFSg), ground granulated blast furnace slag without gypsum (BFS), metakaolin (MK), fly ash (FA), crushed sandstone powder (Si-SP), and limestone powder (Ca-SP). Silica sand (S) was used as fine aggregate for the hardened geopolymer gap filling material. The analysis results (metal oxides) of these raw materials by X-ray fluorescence analysis (XRF) are shown in Table 2. As is clear from Table 2, the main components of the ground granulated blast furnace slag, fly ash, and crushed stone powder with and without gypsum addition are CaO, SiO2, and Al2O3, the main component of limestone powder is CaO, the main component of silica sand is SiO2, and the main components of crushed sandstone powder are SiO2 and Al2O3. In the alkaline aqueous solution, JIS No. 2 sodium silicate (JIS No. WG) or a 10 mol / L sodium hydroxide aqueous solution (JIS No. NH) was used as the alkaline solution, or sodium metasilicate or sodium carbonate was used as the alkaline powder. Although sodium hydroxide is used as the alkali metal hydroxide in this example, potassium hydroxide may also be used. Furthermore, although sodium carbonate is used as the alkali metal carbonate in this example, potassium carbonate may also be used.

[0072] [Table 1]

[0073] The XRF analysis results for each raw material are shown in Table 2.

[0074] [Table 2]

[0075] (Examples 1 to 4 and Reference Example 1: Prototype of test samples of gap filling material and hardened geopolymer for gap filling) The formulations of the raw materials for the gap fillers of Examples 1 to 4 and Reference Example 1 are shown in Table 3. Metakaolin (MK) alone or metakaolin (MK) and crushed stone powder (Si-SP) were used as the powder (P), and these powder raw materials for the gap filler were weighed out. Silica sand (S) was also used as the fine aggregate. The powder and fine aggregate were placed in a plastic bag and aerated. The bag was then shaken and mixed for 2 to 3 minutes. The mixed raw materials were weighed and placed in a plastic beaker. Next, an alkaline aqueous solution (AS) containing sodium silicate (WG) and sodium hydroxide solution (NH) was added, or sodium silicate (WG), sodium hydroxide, and water were added, as shown in Table 3, and the mixture was kneaded for 2 minutes using a metal spatula to prepare the gap filler.

[0076] (Setting test of gap filling material) A stopwatch was started when the alkaline aqueous solution (AS) was poured into the solid raw materials (powder and silica sand), and mixing was continued. The geopolymer mortar mixed with the alkaline aqueous solution (AS) was poured into a φ50mm x H15mm formwork with a base plate at least 2.5mm thick. A setting test was conducted using a setting tester (JIS R 5201 compliant) and standard needles (for initial and final setting) (JIS R 5201 compliant). The initial setting time was the time when the Vigar setting tester reached 1mm above the base plate, and the final setting time was confirmed using the final setting needle. This test was conducted in an environment with a temperature of 20±3°C and a relative humidity of 60±5%.

[0077] (Preparation of strength specimens of geopolymer for gap filling and compression tests) The geopolymer mortar prepared as described above was poured into a cylindrical formwork measuring φ30 × 60 mm, and strength specimens of the gap-filling geopolymer were prepared in accordance with JIS A1108 (2018). All strength specimens were sealed with plastic wrap and left to cure in a thermo-hygrostat at 20°C and a relative humidity of 85%. After 1 day, 3 days, and 28 days of curing, compressive strength tests were conducted on the strength specimens of the gap-filling geopolymer in accordance with the same standard, and the compressive strength (N / mm 2 ) was measured.

[0078] The test results for setting time and compressive strength are summarized in Table 3.

[0079] [Table 3]

[0080] As shown in Table 3, the hardened geopolymer gap-filling materials produced using metakaolin (MK) powder alone or a combination of metakaolin and crushed stone powder (Si-SP) had a setting time of 30 minutes or more and a compressive strength of 80 MPa or more after 28 days of curing. After examining the appropriate type and amount of powder and the type and concentration of alkaline aqueous solution, the gap-filling materials of Examples 1 to 4 and the hardened geopolymer gap-filling materials produced using them satisfied the high strength and required setting time (30 minutes or more). On the other hand, the reference example, in which the two molar ratios, Na / H2O and Si / Na, were outside the ranges of the examples, had a long setting time, but the strength was 25 N / mm 2 It was low.

[0081] (Examples 5 to 11 and Reference Examples 2 to 13: Prototype production of test samples of gap filling material and hardened geopolymer for gap filling) The formulations of the raw materials for the gap fillers of Examples 5 to 11 and Reference Examples 2 to 13 are shown in Table 4. As shown in Table 4, gap fillers were produced in the same manner as in Examples 1 to 4, using gypsum-containing granulated blast furnace slag powder (BFSg) and fly ash (FA) as the powder (P) and a hardening liquid prepared from a mixed aqueous solution of JIS No. 2 water glass (WG) and 10 M sodium hydroxide (NH) as the alkaline aqueous solution (AS). In addition, in the same manner as in Examples 1 to 4, a setting test of the gap filling material was conducted, and strength specimens of the hardened geopolymer for gap filling were prepared and compression tests were conducted. The results are summarized in Table 4.

[0082] [Table 4]

[0083] As shown in Table 4, the gap-filling geopolymer hardened compacts produced using a combination of gypsum-containing granulated blast furnace slag (BFSg) and fly ash (FA) had a setting time of 30 minutes or more and a compressive strength of 80 MPa or more after 28 days of curing. After investigating the appropriate type and amount of gap-filling powder and the type and concentration of the alkaline aqueous solution, the gap-filling geopolymer hardened compacts produced using Examples 5-11 and their corresponding gap-filling geopolymer hardened compacts satisfied the required setting time (30 minutes or more). In contrast, Reference Examples 2-13, in which the molar ratios of Na / H2O and Si / Na were outside the ranges of the examples, did not achieve the required setting time (30 minutes or more), and some Reference Examples had lower strength after 28 days of curing than Examples 5-9.

[0084] (Examples 12 to 34 and Reference Examples 14 to 16: Prototype production of test samples of gap filling material and hardened geopolymer for gap filling) The formulations of the raw materials for the gap fillers of Examples 12 to 34 and Reference Examples 14 to 16 are shown in Table 5. As shown in Table 5, gap fillers were produced in the same manner as in Examples 1 to 4, using gypsum-containing granulated blast furnace slag powder (BFSg) and limestone powder (Ca-SP) or crushed sandstone powder (Si-SP) as the powder (P) and an alkaline aqueous solution (AS) consisting of a mixed aqueous solution of JIS No. 2 water glass (WG) and 10 M sodium hydroxide (NH). In addition, in the same manner as in Examples 1 to 4, a setting test of the gap filling material was conducted, and strength specimens of the hardened geopolymer for gap filling were prepared and compression tests were conducted. The results are summarized in Table 5.

[0085] [Table 5]

[0086] As shown in Table 5, the hardened geopolymer gap-filling compacts produced using a combination of gypsum-containing granulated blast furnace slag powder (BFSg) and stone powder (limestone Ca-SP or sandstone Si-SP powder) had a setting time of 30 minutes or more and a compressive strength of 80 MPa or more after 28 days of curing. After investigating the appropriate type and amount of gap-filling powder and the type and concentration of alkaline aqueous solution, the gap-filling compacts of Examples 12 to 34 and the hardened geopolymer gap-filling compacts produced using them satisfied both high strength and the required setting time (30 minutes or more). On the other hand, in Reference Examples 14 to 16, where the Si / Na ratio of the two molar ratios, Na / H2O and Si / Na, was outside the range of the examples, the required setting time (30 minutes or more) was not achieved.

[0087] (Examples 35 to 40 and Reference Examples 17 to 23: Prototype production of test samples of gap filling material and hardened geopolymer for gap filling) The formulations of the raw materials for the gap fillers of Examples 35 to 40 and Reference Examples 17 to 23 are shown in Table 6. As shown in Table 6, gap fillers were produced in the same manner as in Examples 1 to 4, using ground granulated blast furnace slag with gypsum (BFSg) or ground granulated blast furnace slag without gypsum (BFS) as the powder (P), and an alkaline aqueous solution (AS) consisting of a mixed aqueous solution of JIS No. 2 water glass (WG) and 10 M sodium hydroxide (NH). In addition, in the same manner as in Examples 1 to 4, a setting test of the gap filling material was conducted, and strength specimens of the hardened geopolymer for gap filling were prepared and compression tests were conducted. The results are summarized in Table 6.

[0088] [Table 6]

[0089] As shown in Table 6, the gap-filling geopolymer hardened compacts produced using only gypsum-containing granulated blast furnace slag powder (BFSg) or gypsum-free granulated blast furnace slag powder (BFSg) had a setting time of 30 minutes or more and a compressive strength of 80 MPa or more after 28 days of curing. After investigating the appropriate type and amount of gap-filling powder and the type and concentration of alkaline aqueous solution, the gap-filling geopolymer hardened compacts produced using these gap-filling materials in Examples 35-40 satisfied the required setting time (30 minutes or more). On the other hand, in Reference Examples 17-23, where the Si / Na ratio of the two molar ratios, Na / H2O and Si / Na, was outside the range of the examples, the required setting time (30 minutes or more) was not achieved.

[0090] (Examples 41 to 44: Prototype production of test samples of gap filling material and hardened geopolymer for gap filling) The formulations of the raw materials for the gap fillers of Examples 41 to 44 are shown in Table 7. As shown in Table 7, gap fillers were produced in the same manner as in Examples 1 to 4, using gypsum-containing granulated blast furnace slag powder (BFSg), limestone powder (Ca-SP) and / or crushed sandstone powder (Si-SP) as the powder (P), a setting retarder (TP) containing tartrate as the main component, and an alkaline aqueous solution (AS) prepared from a mixed aqueous solution of JIS No. 2 water glass (WG) and 10 M sodium hydroxide (NH). In addition, in the same manner as in Examples 1 to 4, a setting test of the gap filling material was conducted, and strength specimens of the hardened geopolymer for gap filling were prepared and compression tests were conducted. The results are summarized in Table 7.

[0091] [Table 7]

[0092] As shown in Table 6, the addition of a set retarder to gap-filling geopolymer hardened compacts produced using only gypsum-containing granulated blast furnace slag powder (BFSg) or gypsum-free granulated blast furnace slag powder (BFSg) as the powder resulted in a setting time of 30 minutes or more and a compressive strength of 80 MPa or more after 28 days of curing. The appropriate type and amount of gap-filling powder, as well as the type and concentration of the alkaline aqueous solution, were investigated, and the gap-filling geopolymer hardened compacts produced using these gap-filling materials in Examples 41 to 44 satisfied the required setting time (30 minutes or more).

[0093] (Examples 45-46: Prototype of test samples of gap filling material and gap filling geopolymer hardened body) Next, as shown in Table 8, gypsum-containing blast furnace water granulated powder (BFSg), limestone powder (Ca-SP), and crushed sandstone powder (Si-SP) were used as the powder (P), and sodium metasilicate, or sodium metasilicate and sodium hydroxide aqueous solution was used as the alkali hardener. In order to investigate rational formulations, gap fillers were produced in the same manner as in Examples 1 to 4. In addition, in the same manner as in Examples 1 to 4, a setting test of the gap filling material was conducted, and a test sample of the hardened geopolymer for gap filling was produced and a compression test was conducted. The results are summarized in Table 8.

[0094] [Table 8]

[0095] As shown in Table 8, the gap-filling geopolymer hardened bodies produced using gypsum-containing blast furnace water-granulated powder (BFSg), limestone powder (Ca-SP), and crushed sandstone powder (Si-SP) as powders, sodium metasilicate (17% by mass of powder) and water alone, or sodium metasilicate (17% by mass of powder) and 1M sodium hydroxide aqueous solution, had a setting time of 30 minutes or more and a compressive strength of 80 MPa or more after 28 days of curing. After investigating the appropriate type and amount of gap-filling powder and the composition of the alkaline curing agent, the gap-filling geopolymer hardened bodies produced using them, as in Examples 45-46, satisfied the high strength and required setting time (30 minutes or more).

[0096] (Examples 47-48: Prototype of test samples of gap filling material and gap filling geopolymer hardened body) Next, as shown in Table 8, gap fillers were prepared in the same manner as in Examples 1 to 4, using gypsum-containing granulated blast furnace powder (BFSg), limestone powder (Ca-SP), and crushed sandstone powder (Si-SP) as the powder (P), and sodium carbonate (17% by mass of the powder), or sodium carbonate (17% by mass of the powder) and sodium hydroxide as the alkali hardener. In addition, in the same manner as in Examples 1 to 4, a setting test of the gap filling material was conducted, and strength specimens of the hardened geopolymer for gap filling were prepared and compression tests were conducted. The results are summarized in Table 9.

[0097] [Table 9]

[0098] As shown in Table 9, Example 47, which used only gypsum-containing granulated blast furnace powder (BFSg), limestone powder (Ca-SP), and crushed sandstone powder (Si-SP) as powders, and sodium carbonate water, had a lower compressive strength at 3 days (3D) and a longer setting time than Example 48, in which 10% of the water was replaced with 10 mol / L sodium hydroxide solution. These results suggest that the gap filler of Example 48 has high reactivity and good strength development. However, the compressive strength of Example 48 at 28 days (28D) was lower than that of Example 47. This is likely due to errors in specimen preparation and strength measurement. However, the compressive strength of the hardened geopolymer gap filler of Examples 47-48 was approximately 60 MPa, making it suitable for use in typical civil engineering and construction projects. By appropriately selecting the type and amount of gap filler powder and the composition of the alkaline hardener (BFS or BFSg is 70% or more, and the Na / H2O molar ratio is 0.1361 or more), it is possible to obtain a formulation that satisfies the requirements of a setting time of 30 minutes or more and a compressive strength of 80 MPa or more after 28 days of curing.

[0099] (Adhesion test of hardened geopolymer for gap filling) Next, adhesion tests were conducted on the gap-filling geopolymer hardened body to measure the adhesion strength to anchor elements, which were deformed steel bars and fully threaded bolts, when used as post-installed anchor fixing materials. The specific method of the adhesion test is as follows. (1) Anchor element The deformed steel bar is type: SD345, tip shape: cut to size, size: D16, or The fully threaded bolt is made of SNB7 material, has a cut tip, and is M16 in size. (2) Object to which the anchor element is attached The base material is concrete, and its compressive strength is 24N / mm 2 It was. (3) Manufacturing of hardened geopolymer for gap filling A hammer drill was used to drill holes (hole diameter φ20 mm × drilling depth 80 mm) in the base concrete. Next, as shown in Table 10, gypsum-containing blast furnace water granulated powder (BFSg), limestone powder (Ca-SP), crushed sandstone powder (Si-SP) and / or fly ash (FA) were used as the powder (P), a mixed aqueous solution of sodium silicate and sodium hydroxide was used as the alkaline aqueous solution (AS), and a shrinkage reducing agent (SR) shown in Table 1 was added or not. Except for this, gap fillers were prepared in the same manner as in Examples 1 to 4. The mixed gap filler was attached to a special injection gun and injected into the holes. After that, deformed steel bars and fully threaded bolts were inserted and fixed in place. After curing in a room at 20±3°C and 60±5% RH until the specified age, an adhesion strength test was conducted. (4) Adhesion strength test The adhesive strength test was carried out as follows. A bond strength test jig was assembled for deformed steel bars or fully threaded bolts anchored in the base concrete. The bond strength test jig consisted of a reaction plate with a 24mm inner diameter hole placed on the base concrete, through which the deformed steel bars or fully threaded bolts protruded. A non-deformable reaction table was placed on the reaction plate, and the deformed steel bars or fully threaded bolts were gripped with a center hole jack fixed to the reaction table. The center hole jack was connected to an electric hydraulic pump, and was operated in the direction of pulling the deformed steel bars or fully threaded bolts out of the concrete using hydraulic pressure generated by the hydraulic pump. A load meter and a displacement meter were also attached to the center hole jack, measuring the load generated by the hydraulic jack and the displacement, respectively, and the load and displacement were measured until the maximum load was reached. The adhesive strength was calculated as follows: Adhesion strength = Maximum load / adhesion area Adhesion area = nominal diameter of deformed steel bar or effective diameter of fully threaded bolt x π x drilling depth (actual value) The results are summarized in Tables 10 and 11.

[0100] [Table 10]

[0101] [Table 11]

[0102] As is clear from Tables 10 and 11, when the gap filler is used as a post-installed anchor element fixing material and fixed to each anchor element of deformed steel bars and fully threaded bolts with a gap-filling geopolymer hardener, the bond strength is approximately 17 to 31 N / mm 2 This adhesive strength is comparable to that of conventional Portland cement anchors, making it highly practical.

[0103] From the results of the above examples, the gap filling material of the present invention and the hardened geopolymer for gap filling using the same can be summarized as follows.

[0104] Regarding hardened geopolymer for gap filling, (a) In order to manufacture a concrete with a setting time of 30 minutes or more and a compressive strength of 80 MPa or more after 28 days of curing, 40 to 50% of the total powder (filler) should be granulated blast furnace slag powder (BFSg) or gypsum-free granulated blast furnace slag powder (BFS). (b) It is preferable that 60% or more but less than 100% of the total powder is made of ground granulated blast furnace slag (BFSg, BFS) with or without added gypsum, and that the Si / Na molar ratio and Na / H2O molar ratio of the alkaline aqueous solution, which is the hardening liquid, are 1.097 to 1.324 and 0.103 to 0.143 when fly ash (FA) is mixed, and 0.853 to 1.324 and 0.106 to 0.151 when stone powder (SP) is mixed. Or, (c) When all of the powder is ground granulated blast furnace slag (BFS) without gypsum addition or ground granulated blast furnace slag (BFSg) with gypsum added, it is preferable that the Si / Na molar ratio and Na / H2O molar ratio of the alkaline aqueous solution serving as the hardening liquid be set to (Si / Na) 1.163 to 1.324 and (Na / H2O) 0.135 to 0.140 when BFS is used, and (Si / Na) 1.192 to 1.324 and (Na / H2O) 0.135 to 0.139 when BFSg is used.

[0105] In this case, the above conditions (a) to (c) are met regardless of whether gypsum is contained in or added to the ground granulated blast furnace slag. Therefore, when using ground granulated blast furnace slag that does not contain gypsum, gypsum may be added from the outside as necessary.

[0106] Furthermore, even if a surfactant (water-reducing agent, high-performance water-reducing agent, or superplasticizer) and / or a shrinkage-reducing agent is added, the above conditions (a) to (c) are met, because the surfactant and / or the shrinkage-reducing agent do not affect the Ca elution from the ground granulated blast furnace slag.

[0107] Furthermore, by using a combination of ground granulated blast furnace slag (BFS) or ground granulated blast furnace slag containing gypsum (BFSg) and stone powder (SP) as the powder, with at least 40% of the total powder being BFS or BFSg, and adding a setting retarder whose main component is tartrate, even if the proportion of NH in the alkaline solution used is high, it is possible to produce a gap-filling geopolymer hardened body that is useful as an anchor adhesive or grout filler with a setting time of 30 minutes or more and a compressive strength of 80 MPa or more at 28 days.

[0108] Furthermore, by using metakaolin powder alone as the powder, or by combining metakaolin powder with stone powder (SP), such as crushed sandstone powder (Si-SP) or fly ash, it is possible to produce a geopolymer with a setting time of 30 minutes or more and a compressive strength of 80 MPa or more after 28 days. However, it is preferable that the Si / Na molar ratio and Na / H2O molar ratio of the alkaline aqueous solution used as the hardening liquid be (Si / Na) 0.853 to 1.097 and (Na / H2O) 0.143 to 0.151.

[0109] Furthermore, if gypsum-free / containing granulated blast furnace slag powder (BFS or BFSg), or metakaolin (MK) and fly ash (FA) or stone powder (SP) are used as the filler, and metasilicate sota powder is mixed with the powder as a hardener, and then water or a sodium hydroxide solution of 1 mol / L or more is mixed, a geopolymer with a setting time of 30 minutes or more and a 28-day compressive strength of 80 MPa or more can be produced. However, when mixing sodium hydroxide solution, it is preferable to set the Si / Na molar ratio to 0.471 or less and the Na / H2O molar ratio to 0.0605 or more.

[0110] Furthermore, by powdering gypsum-free / containing granulated blast furnace slag (BFS or BFSg), or metakaolin (MK) with fly ash (FA) or stone powder (SP), mixing sodium carbonate powder with the powder as a hardener, and then mixing in 1 mol / L or more of sodium hydroxide aqueous solution (Na / H2O molar ratio of 0.136 or more), it is possible to create a geopolymer with a setting time of 30 minutes or more and a 28-day compressive strength of 80 MPa or more.

[0111] The addition of fiber fabric or fiber, or the use of fine aggregate other than silica sand, does not affect the above conclusion, as it does not affect the reactivity of the powder (active filler). [Industrial Applicability]

[0112] The gap filling material of the present invention and the gap filling geopolymer hardened body formed using it can be used as a fixing material for post-installed anchor elements, as a grout material for post-tensioning, as a backfill material for buildings, as a filler for cavities in the ground, or as a crack repair material, and can be used to fill a variety of gaps, from small cracks to holes for medium-sized post-installed anchors, sheaths for post-tensioning, as well as the backs of large buildings and cavities in the ground.

Claims

1. a powder which is at least one type of highly reactive active powder selected from metakaolin and ground granulated blast furnace slag, or a mixed powder of the highly reactive active powder and at least one type of low-activity or inactive powder selected from fly ash, stone powder, and slowly cooled ground granulated blast furnace slag; and an alkaline aqueous solution containing at least one of sodium metasilicate and sodium silicate, or at least one of sodium metasilicate and sodium silicate and an alkali metal hydroxide, or containing an alkali metal carbonate or an alkali metal carbonate and an alkali metal hydroxide, A gap filler characterized by being intended to form a geopolymer in a room temperature environment.

2. The gap filler according to claim 1, characterized in that it is at least one selected from the group consisting of a post-installed anchor element fixing material, a grout material for post-tensioning, a backfill material for buildings, a filling material for cavities in the ground, and a crack repair material.

3. 2. The gap filling material according to claim 1, wherein the stone powder is crushed stone powder or powder of at least one rock selected from limestone and siliceous rocks such as sandstone and slate.

4. The gap filling material according to claim 1, characterized in that the powder contains at least one selected from the metakaolin and the ground granulated blast furnace slag, or contains at least one selected from the metakaolin and the ground granulated blast furnace slag and at least one selected from the fly ash and the stone powder.

5. The gap filling material according to claim 1, characterized in that the powder consists of the ground granulated blast furnace slag, or the ground granulated blast furnace slag and 60% or less of the fly ash and / or crushed stone powder in the powder.

6. 2. The gap filling material according to claim 1, wherein the ground granulated blast furnace slag contains or has added thereto gypsum, or does not contain gypsum.

7. This gap filler is such that the alkali metal in the alkaline aqueous solution is sodium, The powder is made of the metakaolin or made of the metakaolin and the stone powder and / or the fly ash, and the molar ratio (Si / Na) of silicon (Si) to sodium (Na) in the alkaline aqueous solution is 0.853 to 1.097, and the water (H 2 The molar ratio of sodium to H 2 O) is 0.143 to 0.151, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.2; or The powder comprises the ground granulated blast furnace slag and the fly ash, and in the alkaline aqueous solution, the molar ratio of silicon to sodium (Si / Na) is 1.097 to 1.324, and the molar ratio of sodium to water (Na / H 2 O) is 0.103 to 0.143, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0; or The powder comprises the ground granulated blast furnace slag and the stone powder, and in the alkaline aqueous solution, the molar ratio of silicon to sodium (Si / Na) is 0.853 to 1.324, and the molar ratio of sodium to water (Na / H 2 O) is 0.106 to 0.151, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0; or The powder is made of the granulated blast furnace slag powder containing or not containing gypsum, and in the alkaline aqueous solution, the molar ratio of silicon to sodium is 1.163 to 1.324, the molar ratio of sodium to water is 0.135 to 0.140, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.0; or The powder is composed of the blast furnace slag powder containing or not containing gypsum, and at least one of the fly ash and the stone powder, and a setting retarder is added, and in the alkaline aqueous solution, the molar ratio of silicon to sodium is 0.853 to 1.097, and the molar ratio of sodium to water is 0.143 to 0.151, and the weight ratio of the alkaline aqueous solution to the powder is 0.3 to 1.

0. Gap filler according to claim 1.

8. The gap filler according to claim 1, characterized in that the sodium metasilicate or the carbonate of the alkali metal is added as an alkali powder to the active powder or the mixed powder of the active powder and the low-activity or inactive powder in a mass ratio of 5 to 20% of the powder, and is further mixed with water or a mixed aqueous solution of the hydroxide of the alkali metal having a concentration of 1 mol / L or more.

9. 10. The gap filler of claim 1, further comprising a set retarder, a surfactant, a shrinkage reducing agent, and / or a fiber fabric or fiber admixed therewith.

10. 2. The gap filler according to claim 1, further comprising coarse aggregate and / or fine aggregate.

11. A gap filling geopolymer hardened body, characterized in that the gap filling material according to any one of claims 1 to 10 forms the geopolymer in a room temperature environment.

Images