JP2014129209A - Grout composition and grout material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grout composition, especially a grout composition for seismic strengthening, which is excellent in fluidity and hardly causes material separation regardless of high content of a fine aggregate, and to provide a grout material, especially a grout material for seismic strengthening, which is excellent in fluidity and hardly causes material separation regardless of high content of a fine aggregate.SOLUTION: Cement and a fine aggregate of a specific grain size are contained at a specific ratio. It is desirable that one or two or more selected from a powder thickener, a powder water reducing agent, an expanding material, a foaming agent, and an antifoaming agent are contained by specific amounts. It is desirable that a specific amount and ratio of water is kneaded.

Description

  The present invention relates to a grout composition and a grout material for seismic reinforcement. More specifically, the present invention relates to a grout composition and a grout material that are excellent in fluidity and hardly cause material separation despite a high content of fine aggregate, and more particularly, to a grout composition for earthquake resistance reinforcement and a grout material for earthquake resistance reinforcement.

  There are various seismic reinforcement methods for reinforced concrete structures such as brace method, additional wall method, and winding method. Grout mortar (see, for example, Patent Documents 1 to 3) is used for these seismic reinforcement methods. In the part filled with grout mortar, in order to integrate existing reinforced concrete members such as pillars and beams with steel braces and reinforced concrete extension walls (bearing walls), reinforcing bars such as anchor bars and spiral bars are used. Many are installed and the volume of grout mortar to be filled is relatively large. For this reason, the grout mortar used for the seismic reinforcement method needs to have excellent fluidity and low exothermicity. In order to obtain low exothermicity, the content of fine aggregate in the grout mortar composition (content of the grout mortar excluding water) is increased to 60% by mass or more, that is, the content of the binder. Must be 40% by mass or less. The binder in the present invention refers to hydraulic substances such as hydraulic cement and blast furnace slag powder, and pozzolans such as activated silica.

  In addition, in the seismic reinforcement method, the mold is often filled with grout mortar after being pumped by a grout pump. When grout mortar with a high content of fine aggregate is pumped with a grout pump, the fluidity of the grout mortar changes greatly before and after pumping, which causes material separation and poor surface condition when the formwork is removed. There was a thing.

JP 2000-086320 A JP 2000-044308 A JP 2008-230890 A

  The present invention provides a solution to the above-mentioned problem, that is, the present invention provides a grout composition that is excellent in fluidity and hardly separates in spite of a high content of fine aggregates, particularly a grout composition for seismic reinforcement. The purpose is to do. Another object of the present invention is to provide a grout material that is excellent in fluidity and hardly separates in spite of a high content of fine aggregates, particularly a seismic reinforcing grout material.

As a result of intensive studies for solving the above problems, the present inventor has found that the above problems can be solved by containing cement and fine aggregates having a specific particle size in a specific ratio, and completed the present invention. That is, the present invention provides a grout composition represented by the following (1) to (3), a grout composition for earthquake-resistant reinforcement represented by (4), a grout material represented by (5), and a grout for earthquake-resistant reinforcement represented by (6) It is a material.
(1) 25 to 45% by mass of powder containing cement and 75 to 55% by mass of aggregate, and the aggregate is less than 1% by mass of particles exceeding 2.5 mm, exceeding 1.2 mm and 2.5 mm The following particles are 30 to 40% by mass, particles exceeding 0.6 mm to 1.2 mm are 23 to 40% by mass, particles exceeding 0.3 mm to 0.6 mm are 15 to 20% by mass, and 0.15 mm. A grout composition in which particles of more than 0.3 mm are 5 to 15% by mass.
(2) 0.001 to 0.005 parts by weight of powder thickener, 0.5 to 1.5 parts by weight of powder water reducing agent, with respect to 100 parts by weight of the inorganic binder containing cement. The above (1) or 2 or more types selected from -12 parts by mass of an expanding material, 0.0005 to 0.01 parts by mass of a foaming agent, and 0.01 to 0.05 parts by mass of an antifoaming agent ( The grout composition of 1).
(3) The grout composition according to the above (1) or (2), wherein 12 to 20 parts by mass of water is kneaded with 100 parts by mass of the grout composition.
(4) A grouting composition for seismic reinforcement comprising the grouting composition according to any one of the above (1) to (3), which is used by kneading an amount of water in an amount of 32 to 45%.
(5) A grout material containing the grout composition according to any one of (1) to (3) above and 12 to 20 parts by mass of water with respect to 100 parts by mass of the grout composition.
(6) A grouting material for seismic reinforcement comprising the grouting composition for seismic reinforcement of (4) above and an amount of water in an amount of 32 to 45% of the water binder ratio.

  According to the present invention, despite the high content of fine aggregates, a grout composition that is excellent in fluidity, hardly separates in material, and has an excellent surface condition when the formwork is removed, particularly a seismic reinforcing grout. A composition is obtained. Further, according to the present invention, it is possible to obtain a grout material which is excellent in fluidity and hardly separates in spite of a high content of fine aggregates, particularly a seismic reinforcing grout material.

  The powder used for the grout composition of the present invention contains an inorganic binder, and the inorganic binder contains cement. The cement in the present invention may be a hydraulic cement. For example, various ordinary Portland cements, eco-cements, low-temperature and moderate-heated portland cements, eco-cements, and fly ash, blast furnaces. Various mixed cements mixed with slag powder, silica fume, fine limestone powder, etc., super fast cement such as “Super Jet Cement” (trade name) manufactured by Taiheiyo Cement Co., Ltd. and “Jet Cement” (trade name) manufactured by Sumitomo Osaka Cement Co., Alumina A cement etc. are mentioned, These 1 type (s) or 2 or more types can be used. It is preferable to use one or two or more selected from various Portland cements, eco-cements, and various mixed cements because it is difficult to impair the workability and it is easy to ensure a long pot life. In addition, in the present invention, the inorganic binder includes, in addition to cement, pozzolanes such as fly ash and silica fume, latent hydraulic materials and expansion materials represented by blast furnace slag powder, but pozzolans and latent hydraulic materials are added separately. Even if it is, it is considered part of the mixed cement. It is preferable to contain 88 to 97 parts by mass of cement with respect to 100 parts by mass of the inorganic binder.

  Moreover, it is preferable to use a powdery admixture for the powder used for this invention, 0.001-0.005 mass part powder thickener with respect to 100 mass parts of said inorganic binders, 0.5-1 1 type selected from 5 parts by mass of powder water reducing agent, 3 to 12 parts by mass of expansion material, 0.0005 to 0.01 parts by mass of foaming agent, and 0.01 to 0.05 parts by mass of antifoaming agent It is more preferable to contain 2 or more types. Grout mortar was prepared by adding 0.001 to 0.005 parts by mass of a powder thickener or / and 0.5 to 1.5 parts by mass of a powder water reducing agent with respect to 100 parts by mass of the inorganic binder. Sometimes it can be pumped with a mortar pump and material separation after pumping can be suppressed. More preferably, 0.001 to 0.003 parts by mass of a powder thickener or / and 0.5 to 1.5 parts by mass of a powder water reducing agent are added to 100 parts by mass of the inorganic binder. Particularly preferably, a powder thickener and a powder water reducing agent are used in combination.

  Examples of the powder thickener used in the present invention include hydroxyalkylcelluloses such as hydroxyethylcellulose (HEC) and hydroxypropylcellulose (HPC), or hydroxyethylmethylcellulose (HEMC), hydroxypropylmethylcellulose (HPMC), hydroxyethylethylcellulose ( HEEC) and other water-soluble celluloses such as hydroxyalkylalkyl celluloses; polysaccharides such as alginic acid, β-1,3 glucan, pullulan and welan gum; polyvinyl compounds such as acrylic resins and polyvinyl alcohol; methyl starch, ethyl starch, propyl starch or Alkyl starch such as methylpropyl starch, hydroxyalkyl starch such as hydroxyethyl starch or hydroxypropyl starch, or hydride Hydroxyalkyl alkyl starch such as starch ethers such as hydroxypropyl starch and the like, it is possible to use alone or in combination.

Further, the powder water reducing agent used in the present invention is not particularly limited, and examples thereof include polycarboxylate-based powder water reducing agents, naphthalene sulfonate-based powder water reducing agents, melamine sulfonate-based powder water reducing agents, and lignin sulfonates. System powder water reducing agent is mentioned, These 1 type (s) or 2 or more types can be used. As the powder water reducing agent to be used, it is preferable to use a powdery high performance water reducing agent or a powdery high performance AE water reducing agent because the compressive strength of the grout mortar at the age of 28 days is easily 45 N / mm ² or more.

  Moreover, 3 to 12 parts by mass of an expanding material, 0.0005 to 0.01 parts by mass of a foaming agent or / and 0.01 to 0.05 parts by mass of a powder antifoaming agent with respect to 100 parts by mass of the inorganic binder. By containing grouting mortar for seismic reinforcement, members such as existing walls and pillars and newly installed members can be more integrated. More preferably, with respect to 100 parts by mass of the inorganic binder, 5 to 9 parts by mass of an expanding material, 0.001 to 0.004 parts by mass of a foaming agent, and / or 0.01 to 0.03 parts by mass of defoaming are used. An agent is included.

  As the expansion material used in the present invention, any material may be used as long as a hydrated crystal such as calcium hydroxide or ettringite grows by hydration and a substance having a large bulk volume is used as a main component. Specifically, quick lime, calcium sulfoaluminate, anhydrous gypsum, magnesia, lime-based expansive material, ettringite-based expansive material and the like are preferable examples, and one or two or more of these or similar substances are used. It is possible. As the expansion material to be used, an expansion material that conforms to JIS A 6202 “Expansion material for concrete” is particularly preferable because the expansion coefficient relative to the amount of mixing is stable. The mixing amount of the expansion material is preferably 3 to 12 parts by mass with respect to 100 parts by mass of the inorganic binder. If the amount is less than 3 parts by mass, it is difficult to obtain the effect of the expanding material. If the amount exceeds 12 parts by mass, the strength of the unconstrained portion may be insufficient. A more preferable mixing amount of the expansion material is 5 to 9 parts by mass with respect to 100 parts by mass of the inorganic binder.

  The foaming agent used in the present invention is not particularly limited as long as it is a powder foaming agent. Specifically, it may be any powder that generates gas after being kneaded with water. This foaming action prevents the grouting mortar from sinking and can be integrated with existing members such as walls and pillars and newly installed members. Integrate with. Specific examples thereof include amphoteric metal powders such as aluminum and zinc, and powdered peroxides. Among these, aluminum powder is preferable because it can effectively foam. The blending amount of the foaming agent is preferably 0.0005 to 0.01 parts by mass with respect to 100 parts by mass of the inorganic binder. If it is less than 0.0005 part by mass, the effect of the foaming agent is difficult to obtain, and if it exceeds 0.01 part by mass, the strength may be insufficient. A more preferable blending amount of the blowing agent is 0.001 to 0.004 parts by mass with respect to 100 parts by mass of the inorganic binder.

  As the powder antifoaming agent used in the present invention, in addition to a commercially available powder antifoaming agent for cement, a commercially available powder antifoaming agent for cement mortar, or a commercially available powder antifoaming agent for concrete, mineral oil-based, ether-based, silicone-based A liquid antifoaming agent such as tributyl phosphate, polydimethylsiloxane or polyoxyalkylene alkyl ether nonionic surfactant supported on an inorganic powder, or a powder antifoaming agent for other uses may be used. The mixing amount of the powder antifoaming agent is preferably 0.01 to 0.05 parts by mass with respect to 100 parts by mass of the inorganic binder. If it is less than 0.01 part by mass, the effect of the powder antifoaming agent is difficult to obtain, and if it exceeds 0.05 part by mass, the strength may be insufficient. A more preferable mixing amount of the powder antifoaming agent is 0.01 to 0.03 parts by mass with respect to 100 parts by mass of the inorganic binder.

  Moreover, as an aggregate used for this invention, the particle | grains exceeding 2.5 mm are 1 mass% or less, the particle | grains exceeding 1.2 mm and 2.5 mm or less are 30-40 mass%, exceeding 0.6 mm and 1.2 mm or less. In the fine aggregate, the particle size is 23 to 40% by mass, the particle size exceeding 0.3 mm and 0.6 mm or less is 15 to 20% by mass, and the particle size exceeding 0.15 mm and 0.3 mm or less is 5 to 15% by mass. I just need it. The material of the aggregate used in the present invention is not particularly limited, and for example, river sand, land sand, sea sand, crushed sand, quartz sand, artificial aggregate, slag aggregate and the like can be used. In the present invention, particles exceeding 2.5 mm refer to particles that remain on a sieve having a nominal nominal size (hereinafter referred to as “mesh”) of 2.5 mm. Moreover, the particle | grains exceeding 1.2 mm and 2.5 mm or less mean the particle | grains which remain on the sieve with a mesh opening of 1.2 mm, and pass a sieve with a mesh opening of 2.5 mm. Similarly, particles exceeding 0.6 mm and not more than 1.2 mm mean particles that remain on the sieve having an aperture of 0.6 mm and pass through the sieve having an aperture of 1.2 mm, exceeding 0.3 mm and not more than 0.6 mm Means particles that remain on a sieve having an aperture of 0.3 mm and pass through a sieve having an aperture of 0.6 mm, and particles having a size exceeding 0.15 mm and not more than 0.3 mm are sieves having an aperture of 0.15 mm. And particles passing through a sieve having a mesh size of 0.3 mm, and particles having a size of 0.15 mm or less mean particles passing through a sieve having a mesh size of 0.15 mm. When the aggregate particle size is out of the above range, material separation is likely to occur.When grout mortar is pumped with a grout pump, the fluidity of the grout mortar changes greatly before and after pump pumping, or the surface condition when the mold is removed. The problem of bad arises.

  In addition to the inorganic binder, powder thickener, powder water reducing agent, expansion agent, foaming agent, powder thickener, aggregate and powder antifoaming agent, the grout composition of the present invention is selected from other admixtures. One or two or more of them can be used in combination as long as the effects of the present invention are not substantially impaired. Examples of such admixtures include polymers for cement, waterproofing materials, rust preventives, shrinkage reducing agents, water retention agents, pigments, fibers, water repellents, whitening prevention agents, quick setting agents (materials), and hardeners (materials). ), A setting retarder, an air entraining agent, a surface curing agent, and the like. In addition, the admixture used in the present invention can be used in the form of powder or aqueous solution, but it does not require a complicated measuring operation etc. at the construction site, and it is just necessary to measure and knead a predetermined amount of water. The so-called “premix product” in which all the ingredients of the grout composition of the present invention are premixed and in powder form is more workable at the construction site. It is preferable that all are powdery or granular.

  In the grout composition of the present invention, the content of the powder containing cement is 25 to 45 mass% and the content of the aggregate is 75 to 55 mass%. When the powder content is less than 25% by mass and the aggregate content exceeds 75% by mass, it is difficult to ensure fluidity as a grout material while suppressing material separation. Moreover, when the content rate of powder exceeds 45 mass% and the content rate of aggregate is less than 55 mass%, since the amount of temperature rise of the grout mortar hardened | cured material by a heat | fever of hydration is large, it is difficult to use for a grout material for seismic reinforcement.

  In the grout composition of the present invention, it is more preferable that a predetermined amount of each of the above materials is mixed in advance using a gravity mixer such as a V-type mixer or a tiltable concrete mixer, a Henschel mixer, a ribbon mixer or the like. In this grout composition, the uneven distribution of the material can be suppressed, which is preferable. The mixer used at this time may be a continuous mixer or a batch mixer. The order in which each material is charged into the mixer is not particularly limited. One by one may be added, or part or all may be added simultaneously. Moreover, the grout composition of this invention can also be manufactured by the method of measuring and throwing each material into containers, such as a bag and a polyethylene container.

  The grout composition of the present invention is used by kneading with 12 to 20 parts by mass of water with respect to 100 parts by mass of the grout composition. The amount of water at this time also takes into account the amount of water contained in the aqueous liquid admixture added to the grout composition when an aqueous liquid admixture (for example, a liquid water reducing agent or rubber latex) is added. If it is less than 12 parts by mass, it is difficult to obtain fluidity, and if it exceeds 20 parts by mass, material separation may occur. From the viewpoint of higher fluidity and difficulty in material separation, 13 to 18 parts by mass is preferable. When the grout composition of the present invention is used for seismic reinforcement, it is preferable to knead and use an amount of water that makes the water binder ratio 32 to 45%.

  Moreover, the grout material of this invention kneads said grout composition and 12-20 mass parts water with respect to 100 mass parts of grout compositions. In the grout material of the present invention, one or two or more selected from the above-mentioned admixtures can be mixed and contained within a range that does not substantially impair the effects of the present invention. At this time, when the aqueous liquid admixture is mixed, the amount of water contained in the aqueous liquid admixture should be taken into account, and it should be 12 to 20 parts by mass with respect to 100 parts by mass of the grout composition. is there. When the grout material of the present invention is used for seismic reinforcement, it is preferable to knead and use an amount of water that makes the water binder ratio 32 to 45%. The method of kneading is not particularly limited, for example, a method of adding and kneading the whole amount of the above grout composition to water, a method of adding and kneading the above grout composition to water while further kneading, the whole amount of water to the above grout composition A method of adding and kneading, a method of adding and kneading water to the above grout composition while further kneading, a method of further kneading a mixture of water and part of each of the above grout compositions divided into two or more , A method of adding and kneading the entire amount of the above grout composition to a combination of water and an aqueous admixture, a method of adding and further kneading the above grout composition to a mixture of water and an aqueous admixture, A method of adding and kneading all the mixture of water and an aqueous admixture to the above grout composition, while kneading a mixture of water and an aqueous admixture to the above grout composition For example the method further kneaded, a method for each further kneaded together those kneaded separately in portions into two or more in to the combined admixture of water and an aqueous and the grout composition and the like. When mixing an admixture other than the above grout composition and water, it may be added to the above grout composition, to water, or to both, and to the above grout composition and water. May be added to the kneaded mixture. Moreover, although the apparatus and kneading apparatus used for kneading are not particularly limited, it is preferable to use a mixer because a large amount can be kneaded. The mixer that can be used may be a continuous mixer or a batch mixer, such as a pan concrete mixer, a pug mill concrete mixer, a gravity concrete mixer, a grout mixer, a hand mixer, and a plaster mixer.

[Example 1]
A grout composition was prepared by putting each material of the blending ratio shown in Table 1 into a Henschel mixer and mixing for 5 minutes. The materials used at this time are shown below. The prepared grout composition and the amount of water shown in Table 1 were put into a grout mixer and then kneaded for 90 seconds to prepare a grout material. The production of the grout material was performed in a constant temperature room at 20 ± 3 ° C. and a humidity of 80% or more.
<Materials used>
Cement: Ordinary Portland cement (manufactured by Taiheiyo Cement)
Foaming agent: Aluminum powder (Toyo Aluminum Co., Ltd.)
Fine aggregate: Silica sand powder water reducing agent: Naphthalenesulfonate-based high-performance water reducing agent (manufactured by Kao Corporation)
Powder water reducing agent 2: Lignin sulfonate-based high-performance water reducing agent (manufactured by Nippon Paper Chemicals)
Powder thickener: Water-soluble cellulose thickener (manufactured by Shin-Etsu Chemical Co., Ltd.)
Expansion material: Lime-based expansion material (manufactured by Taiheiyo Materials Co., Ltd.) conforming to JIS A 6202 “Expansion material for concrete”
Antifoaming agent: Sannopco antifoaming agent (trade name “SN Deformer 55P”, powder)

Water: Sakura City water

After the produced grout material was allowed to stand for 20 minutes, the inside of an injection hose (inner diameter: 2 inches) having a length of 20 m was pumped and the grout material discharged from the tip of the hose was subjected to a fluidity test as shown below as a quality test. , Bleeding test, aggregate sedimentation confirmation test, compressive strength test, and temperature rise measurement. The presence or absence of aggregate sedimentation immediately after kneading, that is, the presence or absence of material separation was confirmed by touch. These results are shown in Table 2. In addition, all quality tests other than the compressive strength test were performed in a temperature-controlled room at 20 ± 3 ° C. and a humidity of 80% or more.
<Quality test method>
According & fluidity test Civil Engineering standard JSCE-F 541 "Test Method of Flowability for Filling Mortar" _was measured flow time by _{J 14} funnel. The flow time was evaluated as ◯ (good) when the flow time was in the range of 6 seconds to 10 seconds, and x (unsuitable) when the value was outside the range.
-Bleeding test Bleeding was measured according to Japan Society of Civil Engineers standard JSCE-F 522 "Testing method for bleeding rate and expansion rate of mortar of prepacked concrete". The grout material discharged from the tip of the hose was put in a polyethylene bag, and bleeding was measured after 2 hours. The case where no bleeding was observed was evaluated as ◯ (good), and the case where bleeding was observed was evaluated as × (bad).
・ Aggregate sedimentation confirmation test (confirmation of inseparability)
In the same manner as the bleeding test, the grout material was put in a polyethylene bag, and after 20 minutes, it was judged by touching whether or not fine aggregates were accumulated on the bottom portion of the plastic bag. The case where fine aggregates settled and collected at the bottom of the plastic bag was evaluated as x (defect), and the case where aggregates did not accumulate was evaluated as good (good).
-Compressive strength test The compressive strength of 28 days of age was measured according to JSCE-G 505 "Method of testing compressive strength of mortar or cement paste using a cylindrical specimen". At this time, the specimen was demolded at the age of 1 day, and then cured in water at 20 ° C. until just before the test. A material having a compressive strength of 45 N / mm ² or more at a material age of 28 days was evaluated as ◯ (good) and a material having a compressive strength of less than 45 N / mm ² was evaluated as x (defective).
-Measurement of temperature rise A specimen with a side of 30 cm was made of a grout material, the center temperature of the specimen was measured, and the maximum temperature and the time from the start of kneading until the maximum temperature was reached were obtained.

Grout striking the embodiment of the present invention (No.1~4) are all just after kneading is in the range flow time of 8 ± 2 seconds using both J ₁₄ funnel after pumping, pumping excellent fluidity The change in fluidity before and after was small. In comparison, the formulation no. In the grout material of No. 5, the flow-down time that was in the range of 8 ± 2 seconds immediately after the kneading was out of the range of 8 ± 2 seconds.

  In addition, the grout materials (Nos. 1 to 4) corresponding to the examples of the present invention did not show bleeding, the fine aggregates did not settle and the material separation was not observed, but the grout materials corresponding to the comparative examples. In (No. 5-6), at least fine aggregate sedimentation was observed after pumping, causing material separation.

In addition, the grout materials (Nos. 1 to 4) corresponding to the examples of the present invention were both excellent in strength with a compressive strength of 45 N / mm ² or more at the age of 28 days. In addition, the grout materials (Nos. 1 to 4) corresponding to the examples of the present invention all had a low exotherm with a maximum temperature of 50 ° C. or less, that is, a temperature increase amount of 30 ° C. or less. From these things, all the grout materials (No. 1-4) which correspond to the Example of this invention had sufficient performance as a grout material for earthquake-proof reinforcement.

  According to the present invention, fluidity, compressive strength, material non-separability and low heat build-up are excellent even after pumping, and it can be used as a grout material for seismic reinforcement. In addition to seismic reinforcement work, it can be used for grout filling work that requires low heat generation, high fluidity and high strength.

Claims (6)

Powder comprising 25 to 45% by mass of cement-containing powder and 75 to 55% by mass of aggregate, and particles having an aggregate exceeding 2.5 mm are 1% by mass or less, and particles exceeding 1.2 mm and not more than 2.5 mm Is 30 to 40% by mass, particles having a diameter of more than 0.6 mm and not more than 1.2 mm are 23 to 40% by mass, particles having a diameter of not less than 0.3 mm and not more than 0.6 mm are 15 to 20% by mass, exceeding 0.15 mm. A grout composition in which particles of 3 mm or less are 5 to 15% by mass. The powder is 0.001 to 0.005 parts by mass of powder thickener, 0.5 to 1.5 parts by mass of powder water reducing agent, 3 to 12 parts by mass with respect to 100 parts by mass of the inorganic binder containing cement. 2 or more types selected from the foaming agent of a part, 0.0005-0.01 mass part foaming agent, and 0.01-0.05 mass part antifoamer. Grout composition. The grout composition according to claim 1 or 2, wherein 12 to 20 parts by mass of water is kneaded and used with respect to 100 parts by mass of the grout composition. A grouting composition for seismic reinforcement comprising the grouting composition according to any one of claims 1 to 3, wherein water is mixed and used in an amount of 32 to 45%. A grout material containing the grout composition according to any one of claims 1 to 3 and 12 to 20 parts by mass of water with respect to 100 parts by mass of the grout composition. A grouting material for seismic strengthening comprising the grouting composition for seismic strengthening according to claim 4 and water in an amount of 32 to 45% of the water binder ratio.