JP2022111343A - grout - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grout composition and grout that can sufficiently secure a serviceable time period even under a high temperature environment and is excellent in an initial expansion property during curing.

SOLUTION: Grout includes: a grout composition including a cement component, an expansive material, a foaming agent, a water-reducing agent, and a thickener; and water. In the cement component, a content ratio of at least one cement selected from a group consisting of normal Portland cement, moderate-heat Portland cement, low-heat Portland cement, mixed cement, and ecological cement is 85 mass% or more based on the total mass of the cement component, and a content ratio of early-strength cement, ultra-high-early-strength cement, fast-hardening cement, and/or alumina cement is 10 mass% or less based on the total mass of the cement component. The cement component is contained 90-98 mass% based on the total mass of the grout composition. The foaming agent is contained 0.0001-0.005 pt.mass relative to 100 pts.mass of the cement component. Aggregate is contained 10 pts.mass or less relative to 100 pts.mass of the cement component. Water is contained 28-40 pts.mass relative to 100 pts.mass of the cement component. In the grout, a settling flow 60 minutes after being kneaded is 212 mm or longer under an environment at 30°C according to 12. Flow Test, "Physical Test Method of Cement" in JIS R 5201:2015, and a difference in flow value between at a time immediately after being kneaded and at a time 60 minutes after being kneaded is 50 mm or shorter.

SELECTED DRAWING: None

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to grout compositions and grouts.

BACKGROUND ART In the fields of civil engineering and construction, gaps in structures are filled with a cement-based grout material such as grout mortar, which has good fluidity. At this time, the fluidity required for the grout material differs depending on the size of the gap to be filled.

For example, when filling a wide gap of 10 cm or more with grout material, some fluidity (for example, J14 funnel specified in JSCE-F 541-1999 "Filling mortar fluidity test method" Flow time using 6 ~ 10 seconds) can be filled. On the other hand, when filling a narrower gap, for example, a gap of 3 cm or less, a grout material having higher fluidity than the grout material described above is used (for example, Patent Documents 1 and 2).

JP 2012-051741 A JP 2012-136403 A

By the way, since grout materials mainly composed of cement are easily affected by the characteristics of cement, depending on the quality of cement, when used in a high temperature environment of 25 ° C or higher, it becomes easy to tighten, and it is difficult to secure a pot life. was there. In addition, since the grout material is sometimes used for gaps, it is also required to have initial expansibility so that gaps do not form after hardening.

Accordingly, it is an object of the present invention to provide a grout composition and a grout that can ensure a sufficient pot life even in a high-temperature environment and have excellent initial expansion properties when cured.

As a result of intensive studies on the above problems, the present inventors have found that by adjusting the content of specific cement and foaming agent, a grout composition that is excellent in initial expansion during hardening while ensuring a sufficient pot life. It has been found that a material and grout can be obtained.

That is, the present invention is, for example, as follows.
[1] A cement component, an expansive agent, and a foaming agent, wherein the cement component is at least one cement selected from the group consisting of ordinary Portland cement, moderate heat Portland cement, low heat Portland cement, mixed cement, and ecocement. The grout composition has a content of 85% by mass or more based on the total mass of the cement component, and a foaming agent content of 0.0001 to 0.005 parts by mass based on 100 parts by mass of the cement component. .
[2] The grout composition of [1], wherein the aggregate content is 10 parts by mass or less per 100 parts by mass of the cement component.
[3] The grout composition of [1] or [2], wherein the cement component content is 90 to 98% by mass based on the total mass of the grout composition.
[4] The grout of any one of [1] to [3], further comprising a thickening agent, and the content of the thickening agent is 0.01 to 0.1 parts by mass relative to 100 parts by mass of the cement component. Composition.
[5] The grout of any one of [1] to [4], which further contains an antifoaming agent, and the content of the antifoaming agent is 0.001 to 0.08 parts by mass relative to 100 parts by mass of the cement component. Composition.
[6] A grout containing the grout composition according to any one of [1] to [5] and water, wherein the water content is 28 to 40 parts by mass based on 100 parts by mass of the cement component.

ADVANTAGE OF THE INVENTION According to this invention, the grout composition and grout which can ensure sufficient pot life even in a high temperature environment and are excellent in initial expansion property at the time of hardening can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.

The grout composition of this embodiment includes a cement component, an expanding material, and a foaming agent.

Various cement components can be used, for example, various Portland cements such as normal, high early strength, ultra high early strength, low heat and moderate heat; mixed cement containing blast furnace slag, fly ash or silica fume; ecocement; A rapid hardening cement etc. are mentioned. One type of cement component may be used alone, or two or more types may be used in combination.

In the cement component of the present embodiment, the content of at least one cement selected from the group consisting of ordinary Portland cement, moderate heat Portland cement, low heat Portland cement, mixed cement and ecocement is based on the total mass of the cement component It is 85% by mass or more. If the content of the cements is outside the above range, it becomes difficult to ensure the pot life under high temperature conditions of 25° C. or higher. The content of the cements may be 90% by mass or more, 95% by mass or more, or 98% by mass, based on the total mass of cement components, from the viewpoint of making it easier to secure a pot life. % or more, or 100% by mass.

In the cement component of the present embodiment, the content of high-early-strength cement, ultra-early-strength cement, rapid-hardening cement, and/or alumina cement may be less than 15% by mass, based on the total mass of the cement component, or 10 mass % or less, 5 mass % or less, 2 mass % or less, or 0 mass %. If the content of the high-early-strength cement, ultra-high-early-strength cement, rapid-hardening cement, and/or alumina cement is within the above range, it tends to be easier to secure a pot life under high-temperature conditions of 25° C. or higher.

The cement component is preferably 90 to 98% by mass, more preferably 92 to 98% by mass, and even more preferably 95 to 98% by mass, based on the total mass of the grout composition. If the content of the cement component is within the above range, it becomes easier to obtain better fluidity.

Any expansive material may be used as long as it is a JIS-compliant expansive material (JIS A 6202:2008) generally used as an expansive material for concrete. Examples of the expansive material include an expansive material mainly composed of free quicklime (quicklime-based expansive material), an expansive material mainly composed of erwin (ettringite-based expansive material), and a composite expansive material of free quicklime and an ettringite-forming substance. mentioned. One type of the expanding material may be used alone, or two or more types may be used in combination. It is preferable to use an expanding material having a Blaine specific surface area of 2000 to 6000 cm ² /g.

The content of the expanding material is preferably 1 to 4.5 parts by mass, preferably 1.2 to 4 parts by mass, and 1.5 to 3 parts by mass with respect to 100 parts by mass of the cement component. is more preferred. If the content of the expansive agent is within the above range, cracks tend to occur less easily after curing while ensuring the pot life.

The foaming agent is not particularly limited, and may be, for example, a substance that generates gas after kneading with water. Examples of foaming agents include powders of amphoteric metals such as aluminum and zinc, and peroxides. As the foaming agent, aluminum powder is preferable from the viewpoint of effectively foaming and being able to further exhibit the expansion effect.

The content of the foaming agent is 0.0001 to 0.005 parts by mass with respect to 100 parts by mass of the cement component. If the content of the foaming agent is outside the above range, there is a risk that the initial expandability at the time of curing will be poor, or that excessive expansion will lead to a decrease in strength. The content of the foaming agent is preferably 0.0002 to 0.002 parts by mass relative to 100 parts by mass of the cement component, from the viewpoint of making it easier to exhibit more appropriate expansion performance during curing, and 0.0003 More preferably, it is up to 0.001 part by mass.

The grout composition of this embodiment may contain an antifoaming agent. The antifoaming agent is not particularly limited as long as it is an antifoaming agent used in general concrete. Ether-based antifoaming agents and silicon-based antifoaming agents can be mentioned.

The content of the antifoaming agent is preferably 0.001 to 0.08 parts by mass, more preferably 0.002 to 0.05 parts by mass, more preferably 0.003 parts by mass, based on 100 parts by mass of the cement component. More preferably, it is up to 0.02 parts by mass. If the content of the antifoaming agent is within the above range, better fluidity is likely to be obtained, and strength development during curing is likely to be excellent.

The grout composition of this embodiment may contain a thickening agent. The type of thickener is not particularly limited, and examples thereof include cellulose-based thickeners, acrylic thickeners, and guar gum-based thickeners. A cellulose-based thickener is preferred as the thickener. Cellulosic thickeners include, for example, carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose. A thickener may be used individually by 1 type, and may be used in combination of 2 or more types.

The content of the thickener is preferably 0.01 to 0.1 parts by mass, more preferably 0.015 to 0.08 parts by mass, more preferably 0.02 parts by mass with respect to 100 parts by mass of the cement component. More preferably, it is up to 0.06 parts by mass. If the content of the thickener is within the above range, better fluidity is likely to be obtained, and bleeding tends to occur less.

The grout composition of the present embodiment may contain fine aggregate within a range that does not impair the effects of the present invention. Examples of fine aggregates include river sand, silica sand, crushed sand, cold water stone, limestone sand, and slag aggregate. Fine aggregates may be used singly or in combination of two or more.

The content of the fine aggregate is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 2 parts by mass or less with respect to 100 parts by mass of the cement component. Further, the grout composition of the present embodiment may not substantially contain fine aggregate. In the present specification, "substantially free of fine aggregates" refers to 0 to 0.5 parts by mass with respect to 100 parts by mass of cement components. If the content of the fine aggregate is within the above range, the filling properties for smaller gaps are likely to be improved.

Various admixtures (materials) may be added to the grout composition of the present embodiment as long as the effects of the present invention are not impaired. Examples of admixtures (materials) include firming agents, waterproof agents, rust inhibitors, shrinkage reducing agents, water retention agents, pigments, water repellent agents, anti-efflorescence agents, fibers, and polymers.

The grout composition of the present embodiment can be prepared by mixing the above components with a kneading device that is commonly used, and the device is not particularly limited. Examples of kneading tools include hand mixers, tilting mixers, and twin-screw mixers.

The grout composition of the present embodiment can be prepared as a grout by mixing with water, and the water content may be appropriately adjusted according to the application. The content of water is preferably 28 to 40 parts by mass, more preferably 30 to 38 parts by mass, even more preferably 32 to 36 parts by mass based on 100 parts by mass of the cement component. If the water content is within the above range, it is easier to ensure fluidity, and it is easier to suppress the occurrence of material separation, an increase in shrinkage of the cured product, and a decrease in initial strength development.

The grout of the present embodiment can be prepared using the same kneading equipment as for ordinary grout, and is not particularly limited. As the kneading device, for example, those described above can be used.

The grout composition and grout of the present embodiment can ensure a sufficient pot life even in a high-temperature environment of 25° C. or higher, and are excellent in initial expansion property during curing. Therefore, the grout composition and grout of the present embodiment can be used as a gap-filling grout as a material for repairing, reinforcing, and filling narrow gaps and cavities. Since it can be secured, it is also suitable for use in high-temperature environments such as tunnels. The method of using the grout of the present embodiment can be selected as appropriate, and for example, a method of pouring and filling the gap can be selected.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited thereto.

Materials used in Examples are as follows.
・Cement Ordinary Portland cement High-early-strength cement ・Expansive material (quicklime-based expansive material)
・Tightening material (calcium aluminate type)
・Water reducing agent (melamine water reducing agent)
・Antifoaming agent (polyether antifoaming agent)
・Blowing agent (aluminum powder)

[Preparation of grout]
A grout composition was formulated and designed with the proportions of each material shown in Table 1. In an environment of 30° C. or 25° C., each material of the grout composition blended and designed in Table 1 and water were added to a cylindrical container and kneaded with a hand mixer for 90 seconds to prepare about 13 L of grout. Water was added in an amount of 34 parts by mass (30° C. environment product) or 35 parts by mass (25° C. environment product) with respect to 100 parts by mass of cement.

[Evaluation method]
・Fluidity retention property confirmation test JIS R 5201: 2015 “Physical test method for cement” 12. In the flow test, static flow (0 stroke) without falling motion was measured 15 times. Measurements were made at 30°C or 25°C. The difference in flow value between immediately after kneading and 60 minutes after kneading was determined, and a difference of 50 mm or less was evaluated as good. The mixture was stirred for 5 seconds with a hand mixer every 15 minutes after kneading.
Table 2 shows the test results.
・ Compressive strength The compressive strength of the hardened grout at an age of 8 hours was measured according to the Japan Society of Civil Engineers standard JSCE-G 505-2010 "Compressive strength test method for mortar or cement paste using a cylindrical specimen (draft)". . The dimensions of the specimen were 50 mm in diameter and 100 mm in height. Preparation and curing were always carried out in a constant temperature bath at 30°C or 25°C. Table 3 shows the test results.
・Initial expansion test The initial expansion rate of the cured body was measured at 30 ° C. or 25 ° C. in accordance with JSCE-F-533-2013 "PC grout bleeding rate and expansion rate test method" of the Japan Society of Civil Engineers standard. Table 4 shows the test results.

Claims (7)

a grout composition comprising a cement component, an expanding agent, a foaming agent, a water reducing agent, and a thickening agent; and water;
In the cement component, the content of at least one cement selected from the group consisting of ordinary Portland cement, moderate heat Portland cement, low heat Portland cement, mixed cement and ecocement is 85 mass based on the total mass of the cement component. % or more, and the content of high-early-strength cement, ultra-early-strength cement, rapid-hardening cement, and/or alumina cement is 10% by mass or less based on the total mass of cement components,
The content of the cement component is 90 to 98% by mass based on the total mass of the grout composition,
The content of the foaming agent is 0.0001 to 0.005 parts by mass with respect to 100 parts by mass of the cement component,
The aggregate content is 10 parts by mass or less with respect to 100 parts by mass of the cement component,
The water content is 28 to 40 parts by mass with respect to 100 parts by mass of the cement component,
JIS R 5201: 2015 "Physical Test Method for Cement"12. A grout having a static flow of 212 mm or more 60 minutes after kneading based on a flow test, and a difference in flow value between immediately after kneading and 60 minutes after kneading within 50 mm. The grout according to claim 1, wherein the expansive material is a quicklime-based expansive material, and the content of the expansive material is 1 to 4.5 parts by mass with respect to 100 parts by mass of the cement. The grout according to claim 1 or 2, wherein the water reducing agent is a melamine-based water reducing agent, and the content of the water reducing agent is 0.11 to 0.97 parts by mass with respect to 100 parts by mass of the cement. 4. Any one of claims 1 to 3, wherein the thickener is a cellulose-based thickener, and the content of the thickener is 0.01 to 0.1 parts by mass with respect to 100 parts by mass of the cement. grout as described above. The grout according to any one of claims 1 to 4, further comprising an antifoaming agent, the content of the antifoaming agent being 0.001 to 0.08 parts by mass with respect to 100 parts by mass of the cement. The grout of any one of claims 1-5, further comprising a binding material. The grout according to any one of claims 1 to 6, which is for gap filling.