Grout composition, grout mortar, additives for grout composition

Abstract

The present invention provides a grout composition that exhibits good fluidity retention and suppresses bleeding. [Solution] A grout composition containing a binder exhibiting hydraulic properties, wherein the pass-through rate of a sieve with a mesh size of 90 μm is 30 to 60% by mass, the pass-through rate of a sieve with a mesh size of 45 μm is 20 to 50% by mass, and the content of Erimite in the mineral composition of the fine powder that passes through the 45 μm sieve is 0.5 to 5% by mass, or the content of calcium carbonate in the mineral composition of the fine powder that passes through the 45 μm sieve is 2 to 20% by mass.

Description

[Technical Field]

[0001] This invention relates to grout compositions, grout mortar, and additives for grout compositions. [Background technology]

[0002] In the civil engineering and construction fields, cement-based grout compositions generally consist of cement with a water-reducing agent added. To this, ettringite-based expansive agents, lime-based expansive agents, or ettringite-lime composite expansive agents, or foaming agents such as aluminum powder are added as needed to create a non-shrinking material. Fine aggregates such as river sand or silica sand are then mixed in, and this material is widely used to fill small voids in concrete structures, voids in top-down construction methods, repair and reinforcement areas of structures, and under base plates of machinery and under track decks.

[0003] Regarding grout compositions, fast-setting types containing fast-setting materials or fast-setting cement are known, as described in Patent Documents 1 and 2. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2001-97759 [Patent Document 2] Japanese Patent Publication No. 2006-27937 [Overview of the project] [Problems that the invention aims to solve]

[0005] According to Patent Documents 1 and 2, a grout composition with excellent strength development and a certain degree of fluidity can be obtained, but it is unclear whether better fluidity can be ensured and bleeding can be suppressed. In grout compositions, ensuring good fluidity and suppressing bleeding are expected to become important issues in the future, considering workability and post-construction quality.

[0006] Based on the above, the present invention aims to provide a grout composition that has good flow retention properties and can suppress bleeding. [Means for solving the problem]

[0007] As a result of diligent research to solve the above problems, the inventors have come up with the present invention described below and found that it can solve the problems. That is, the present invention is as follows.

[0008] [1] A grout composition comprising a binder exhibiting hydraulic properties, wherein the pass-through rate of a sieve with a mesh size of 90 μm is 30 to 60% by mass, the pass-through rate of a sieve with a mesh size of 45 μm is 20 to 50% by mass, and the content of elymite in the mineral composition of the fine powder that passes through the sieve with a mesh size of 45 μm is 0.5 to 5% by mass. [2] A grout composition comprising a binder exhibiting hydraulic properties, wherein the pass-through rate of a sieve with a mesh size of 90 μm is 30 to 60% by mass, the pass-through rate of a sieve with a mesh size of 45 μm is 20 to 50% by mass, and the calcium carbonate content in the mineral composition of the fine powder that passes through the sieve with a mesh size of 45 μm is 2 to 20% by mass. [3] The grout composition according to [1] or [2], wherein the gypsum content in the mineral composition of the fine powder is 1 to 10% by mass. [4] The BET specific surface area of ​​the fine powder is 0.5 to 2.5 m². 2 A grout composition according to any one of [1] to [3], wherein the amount is / g. [5] A grout composition according to any one of [1] to [4], comprising 90 to 250 parts by mass of fine aggregate per 100 parts by mass of the binder. [6] A grout composition according to any one of [1] to [5], comprising a water-reducing agent. [7] A grout composition according to any one of [1] to [6], comprising a foaming agent. A grout mortar comprising the grout composition described in any one of [1] to [7] and water, wherein the grout mortar contains 30 to 55 parts by mass of water per 100 parts by mass of the binder. [9] An additive for grout compositions having a sieve passage rate of 95% by mass or more with a mesh opening of 45 μm, and containing erythramine, calcium carbonate, and gypsum as mineral components, with the total content of these components being 10% by mass or more. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a grout composition that has good flow retention properties and can suppress bleeding. [Modes for carrying out the invention]

[0010] Hereinafter, one embodiment of the present invention (hereinafter sometimes referred to as "this embodiment") will be described.

[0011] [Grout composition] The grout composition according to this embodiment includes a binder that exhibits hydraulic properties. By including a binder that exhibits hydraulic properties, good hardening properties can be obtained after grouting.

[0012] Examples of binders exhibiting hydraulic properties include general cement, gypsum, inorganic expansive agents, and sulfoaluminate cement. Gypsum may be included as a constituent material or as part of the mineral composition of inorganic expansive agents.

[0013] Examples of general cements include various types of Portland cement such as ordinary, rapid-hardening, ultra-rapid-hardening, low-heat, and moderate-heat cements; blended cements containing blast furnace slag, fly ash, or silica fume; and eco-cements.

[0014] Inorganic expansive agents play a role in reducing the drying shrinkage of mortar or further suppressing the generation of bleeding water. Examples of inorganic expanding agents include ettringite-based expanding agents, lime-based expanding agents mainly composed of free lime, and ettringite-lime composite expanding agents, with ettringite-based expanding agents and / or ettringite-lime composite expanding agents being preferred. The Blaine specific surface area of ​​inorganic expansive materials is 2000-9000 cm². 2It is preferably within the range of / g.

[0015] The above ettringite-based expansive material is generally produced by blending CaO raw material, Al2O3 raw material, and CaSO4 raw material in a predetermined ratio and performing heat treatment at 1,100 to 1,600 °C using an electric furnace or a rotary kiln.

[0016] Examples of the CaO raw material include limestone and slaked lime, examples of the Al2O3 raw material include bauxite and aluminum residue ash, and examples of the CaSO4 raw material include gypsum dihydrate, hemihydrate gypsum, and anhydrous gypsum.

[0017] The aforementioned ettringite lime composite expansive material is a substance obtained by heat-treating CaO raw material, Al2O3 raw material, Fe2O3 raw material, and CaSO4 raw material, and is an expansive substance containing free lime and anhydrous gypsum.

[0018] When the ettringite-based expansive material and the ettringite lime composite expansive material are used in combination, the mass ratio thereof (ettringite-based expansive material / ettringite lime composite expansive material) is preferably 0.15 to 18, more preferably 0.2 to 16, from the viewpoint of exerting their combined effects.

[0019] The inorganic expansive material is preferably contained in an amount of 0.5 to 9 parts by mass, more preferably 1 to 7 parts by mass, per 100 parts by mass of the binder. By containing 0.5 to 9 parts by mass, the generation of bleeding water can be further suppressed, or the decrease in strength development due to over-expansion can be prevented.

[0020] Sulfoaluminate cement is a hydraulic cement produced by mixing calcia, alumina, sulfur trioxide, etc., and firing it in a kiln or melting and cooling it in an electric furnace to obtain clinker mainly composed of 3CaO·3Al2O3·CaSO4(Yeelimite) and 2CaO·SiO2(Blite). Appropriate amounts of limestone and gypsum are then added and crushed. It is a cement specified in the People's Republic of China National Standard GB20472-2006 "Sulfoaluminate Cement". Sulfoaluminate cement is classified into rapid-hardening sulfoaluminate cement, low-alkali sulfoaluminate cement, and self-stressing sulfoaluminate cement, and commercially available types can generally be used.

[0021] The particle size of sulfoaluminate cement is determined from the perspective of initial strength development by the Blaine specific surface area (Blaine value of 3,000 cm²). 2 Preferably, it is 4,500 to 6,000 cm² or more. 2 It is more preferable that it be / g. In this specification, the Blaine specific surface area can be measured using a Blaine air permeability device in accordance with JIS R 5201 (Physical Testing Methods for Cement).

[0022] The sulfoaluminate cement is preferably present in 1 to 6 parts by mass, and more preferably in 2 to 4 parts by mass, per 100 parts by mass of the binder. Including it within the above range can further suppress the generation of bleeding water or prevent a decrease in strength development.

[0023] In this embodiment, the content of the binder in the grout composition is preferably 28 to 53% by mass, and more preferably 33 to 50% by mass, from the viewpoint of making the binder's effect more effective.

[0024] The grout composition according to this embodiment has a sieve passage rate of 30 to 60% by mass with a mesh opening of 90 μm, preferably 32 to 57% by mass, and more preferably 34 to 55% by mass. If the sieve passage rate is less than 30% by mass, the strength will decrease, and if it exceeds 60% by mass, the fluidity and its retention will decrease.

[0025] Furthermore, the grout composition according to the embodiment has a sieve passage rate of 20 to 50% by mass with a mesh size of 45 μm, preferably 25 to 47% by mass, and more preferably 30 to 45% by mass. If the sieve passage rate is less than 20% by mass, bleeding will occur, and if it exceeds 50% by mass, the fluidity and its retention will decrease.

[0026] In this embodiment, the mineral composition of the fine powder that passes through a sieve with a mesh size of 45 μm includes erythramide and / or calcium carbonate. When E-rimite is included, the E-rimite content is preferably 0.5 to 5% by mass, more preferably 0.7 to 4.5% by mass, and more preferably 1 to 4% by mass. If the above content is less than 0.5% by mass, bleeding will occur, and if it exceeds 5% by mass, the flow retention will decrease. In this specification, the mineral composition can be determined, for example, by Rietveld analysis based on powder X-ray diffraction patterns.

[0027] Furthermore, if the fine powder contains calcium carbonate, the calcium carbonate content is preferably 2 to 20% by mass, and more preferably 4 to 15% by mass. A calcium carbonate content of 2 to 20% by mass allows for stable suppression of bleeding.

[0028] Furthermore, the gypsum content in the mineral composition of the fine powder is preferably 1 to 10% by mass, and more preferably 2 to 7% by mass. A calcium carbonate content of 1 to 10% by mass can improve flow retention and strength development.

[0029] Furthermore, the BET specific surface area of ​​the fine powder is 0.5 to 2.5 m². 2 It is preferable that the value be / g, and 0.7 to 2m 2 It is more preferable that the BET specific surface area is 0.5 to 2.5 m². 2 Being at a density of / g provides good fluidity and retention, allowing for stable suppression of bleeding.

[0030] The grout composition of this embodiment preferably contains a foaming agent and / or a water-reducing agent.

[0031] The foaming agent is used to more effectively prevent the grout composition from settling or shrinking due to bleeding while it is still wet after application. Preferably, the foaming agent is a gas-foaming agent that generates gas after being mixed with water.

[0032] Examples of gas-foaming substances include oily substances such as vegetable oils and mineral oils. Examples of gas-foaming substances include powdered substances such as flaky aluminum powder surface-treated with stearic acid and aluminum powder produced by atomization. Examples of gas-foaming substances include nitrogen gas-foaming substances that foam nitrogen gas under an alkaline atmosphere, such as azo compounds, nitroso compounds, and hydrazine derivatives. Examples of gas-foaming substances include percarbonates such as sodium percarbonate, potassium percarbonate, and ammonium percarbonate; perborates such as sodium perborate and potassium perborate; permanganates such as sodium permanganate and potassium permanganate; and peroxides such as hydrogen peroxide.

[0033] As the gas foaming material mentioned above, it is preferable to use aluminum powder that has been surface-treated with stearic acid or the like, as it has a significant effect in suppressing settling.

[0034] From the viewpoint of further suppressing bleeding, the content of the foaming substance in the grout composition is preferably 0.0001 to 1% by mass, and more preferably 0.0005 to 0.5% by mass.

[0035] The water-reducing agent helps to disperse each material and also plays a role in improving the fluidity of the grout mortar, which is formed by adding water to the grout composition.

[0036] The water-reducing agent is not particularly limited, and examples include naphthalene sulfonic acid-based water-reducing agents, lignin-based water-reducing agents, naphthalene-based water-reducing agents, melamine-based water-reducing agents, aminosulfonic acid-based water-reducing agents, and polycarboxylic acid-based water-reducing agents, which can be used individually or in combination.

[0037] From the viewpoint of better fluidity, the water-reducing agent content in the grout composition is preferably 0.05 to 1% by mass, and more preferably 0.1 to 0.7% by mass.

[0038] The grout composition according to this embodiment can be manufactured, for example, by appropriately mixing at least one of general cement, an inorganic expansive agent, and sulfoaluminate cement with gypsum, calcium carbonate, fine aggregate, foaming agent, water-reducing agent, etc., and crushing or otherwise performing other actions as needed. Mixing equipment such as tilting drum mixers, omni mixers, Henschel mixers, V-type mixers, and Nauta mixers can be used for mixing.

[0039] Standard fine aggregates can be used as the aggregate material. Various admixtures can also be mixed in.

[0040] The fine aggregate content is preferably 90 to 250 parts by mass, and more preferably 95 to 220 parts by mass, per 100 parts by mass of binder. Having a fine aggregate content within this range provides good fluidity and retention, stably suppresses bleeding, and allows for better strength development.

[0041] Furthermore, from the viewpoint of efficiently exhibiting its function, the content of the fine powder is preferably 10 to 80% by mass, and more preferably 20 to 70% by mass, in the grout composition.

[0042] The coarse powder that does not pass through a sieve with a mesh size of 90 μm preferably accounts for 40 to 70% by mass of the grout composition, and more preferably 43 to 68%. It is preferable that the coarse powder completely passes through a sieve with a mesh size of 5 mm. Furthermore, the amount of powder that passes through a sieve with a mesh size of 90 μm but does not pass through a sieve with a mesh size of 45 μm is preferably 3 to 40% by mass, and more preferably 5 to 30% by mass, in the grout composition.

[0043] [Grout mortar] The grout mortar according to this embodiment contains the grout composition of the present invention described above and water, with 30 to 55 parts by mass of water per 100 parts by mass of binder in the grout mortar composition. In other words, the grout mortar of this embodiment can be manufactured by mixing the grout composition and water. By using 30 to 55 parts by mass of water in the mixing process, good fluidity and strength can be ensured. Preferably, the amount of water is 35 to 50 parts by mass per 100 parts by mass of binder.

[0044] The method of mixing the grout composition with water is not particularly limited, but it is preferable to use a hand mixer with a rotation speed of 900 rpm or higher, a normal high-speed grout mixer, or a twin-screw forced mixer.

[0045] When mixing with a hand mixer or high-speed grout mixer, it is preferable to first put a predetermined amount of water into a container such as a pail or mixer, and then add the grout mortar composition while rotating the mixer, and mix for 3 minutes or more.

[0046] Furthermore, when mixing with a forced mixer, it is preferable to, for example, put the grout composition into the mixer beforehand, add a predetermined amount of water while the mixer is rotating, and mix for at least 4 minutes.

[0047] The mixed grout composition is typically pumped to the application site using a manual injection gun, a diaphragm-type hand pump, or a squeeze-type mortar pump, and then filled in, becoming a hardened body.

[0048] [Additives for grout compositions] The additive for the grout composition according to this embodiment has a sieve passage rate of 95% by mass or more with a mesh opening of 45 μm, and its mineral composition includes erythramine, calcium carbonate, and gypsum, with the total content of these being 10% by mass or more. The above-mentioned additive for grout compositions can be mixed, for example, with a grout composition (preferably the grout composition of the present invention) to obtain a grout composition that has good flow retention and can suppress bleeding. Furthermore, it is preferable that the additive for the grout composition passes through a sieve with a mesh size of 90 μm.

[0049] In the additives for the grout composition, the amount of E-rimite is preferably 0.5 to 5% by mass, and more preferably 1 to 4% by mass. In the additives for the grout composition, calcium carbonate is preferably present in an amount of 1 to 10% by mass, and more preferably in an amount of 2 to 7% by mass. In the additives for the grout composition, gypsum is preferably present in an amount of 1 to 10% by mass, and more preferably in an amount of 2 to 7% by mass. In addition to erymite, calcium carbonate, and gypsum, other mineral compositions include alite, belite, aluminate, and ferrite.

[0050] The additive for the grout composition according to this embodiment can be manufactured by appropriately mixing at least one of general cement, an inorganic expansive agent, and sulfoaluminate cement with gypsum, calcium carbonate, fine aggregate, foaming agent, water-reducing agent, etc., and crushing or otherwise performing other actions as necessary. [Examples]

[0051] <Material> • General cement: Ordinary Portland cement (commercially available, Blaine value 3,500 cm²) 2 / g) · Special cement: Sulfoaluminate cement (commercial product, free lime 0 parts by mass, Yeelimite 50 parts by mass, C2S 10 parts by mass, anhydrous gypsum 10 parts by mass, calcium carbonate 25 parts by mass, Blaine value 5,000 cm 2 / g)) · Expansive agent A: Ettringite-based expansive agent (commercial product, free lime 20 parts by mass, Yeelimite 30 parts by mass, anhydrous gypsum 45 parts by mass, Blaine value 6,000 cm 2 / g) · Expansive agent B: Ettringite-lime composite expansive agent (commercial product, Blaine value 3,700 cm 2 / g) · Limestone fine powder: Calcium carbonate (commercial product, Blaine value 5,000 cm 2 / g) · Water reducing agent: Naphthalene sulfonate-based water reducing agent (commercial product) · Foaming agent: Aluminum powder (commercial product) · Water: Tap water · Fine aggregate: Lime sand (commercial product)

[0052] <Preparation of grout composition> Cement, expansive agents A and B were mixed in the proportions shown in Table 1 below to prepare a binder. To this binder, a water reducing agent, a foaming agent, and a fine aggregate were mixed in the proportions shown in Table 1 below, and then a grout composition with a sieve passing rate of 90 μm and a sieve passing rate of 45 μm, as shown in Table 1 below, was prepared. Also, the mineral composition in the fine powder passing through the 45 μm sieve is shown in Table 1.

[0053] <Preparation of grout mortar> Water was added to the prepared grout mortar composition and kneaded with a hand mixer for 120 seconds to prepare grout mortar. The water / binder ratio was 36%.

[0054] <Evaluation of grout mortar> The following evaluations (a) to (d) were carried out. The results are shown in Table 1. (a) Consistency (seconds): The J14 funnel flow value was measured immediately after the preparation of the grout mortar and 30 minutes after the preparation in accordance with the "Test Method for Fluidity of Filling Mortar" in the Standard Specification of the Japan Society of Civil Engineers (JSCE-F541-1999). Good fluidity retention can be indicated by consistency of 4 to 12 seconds (preferably 4 to 10 seconds) immediately after mixing, and 20 seconds or less after 30 minutes. (b) Bleeding rate (%): The bleeding rate of the prepared grout mortar was measured in accordance with the Japan Society of Civil Engineers Standard Specifications (JSCE-F542-1999) "Test Method for Bleeding Rate and Expansion Rate of Filling Mortar". (c) Setting time: The initial and final setting times of the prepared grout mortar were measured in accordance with JIS A 1147 "Test method for setting time of concrete". Preferably, the condensation time is 1 hour or more from the start of condensation to 15 hours or less from the end of condensation. (d) Compressive strength (N / mm 2 ): In accordance with the Japan Society of Civil Engineers Standard Specifications (JSCE-G541-1999) "Method for Testing the Compressive Strength of Filling Mortar," grout mortar was cast into formwork in a constant temperature and humidity chamber at 20°C and 80%RH, and the compressive strength at 1 day of age was measured.

[0055] [Table 1] [Industrial applicability]

[0056] The grout composition of the present invention can be suitably used for various grouting operations, such as filling in small voids in concrete structures, voids in top-down construction methods, repair and reinforcement areas of structures, and under base plates of machinery and under track decks.

Claims

1. It contains a binder that exhibits hydraulic properties. The sieve passage rate for a mesh opening of 90 μm is 30 to 60 mass%, A grout composition having a sieve passage rate of 20 to 50% by mass through a sieve with a mesh size of 45 μm, and the content of elymite in the mineral composition of the fine powder that passes through the sieve with a mesh size of 45 μm is 0.5 to 5% by mass.

2. It contains a binder that exhibits hydraulic properties. The sieve passage rate for a mesh opening of 90 μm is 30 to 60 mass%, A grout composition having a sieve passage rate of 20 to 50% by mass through a sieve with a mesh size of 45 μm, and a calcium carbonate content in the mineral composition of the fine powder passing through the sieve with a mesh size of 45 μm being 2 to 20% by mass.

3. The grout composition according to claim 1 or 2, wherein the gypsum content in the mineral composition of the fine powder is 1 to 10% by mass.

4. The BET specific surface area of ​​the aforementioned fine powder is 0.5 to 2.5 m². ２ The grout composition according to claim 1 or 2, wherein the amount is / g.

5. The grout composition according to claim 1 or 2, comprising 90 to 250 parts by mass of fine aggregate per 100 parts by mass of the binder.

6. A grout composition according to claim 1 or 2, comprising a water-reducing agent.

7. A grout composition according to claim 1 or 2, comprising a foaming agent.

8. A grout mortar comprising the grout composition according to claim 1 or 2 and water, wherein the amount of water is 30 to 55 parts by mass per 100 parts by mass of the binder.

9. The sieve passage rate for a mesh opening of 45 μm is 95% by mass or more. An additive for grout compositions, comprising elymite, calcium carbonate, and gypsum as mineral components, with the total content of these components being 10% by mass or more.

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