JP2001253751A - Grout material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grout material which is high in fluidity and from which a hardened body high in toughness and excellent in earthquake resistance can be obtained and to provide a construction method to use this grout material. SOLUTION: This grout material contains at least a hydraulic material, a reinforcing fiber and water. A polyvinyl alcohol-based fiber at least a part of which has 8-270 dtex fineness and 4 cN/dtex or higher tenacity is used as the reinforcing fiber. The standard formed body obtained from the grout material has 45-120 MPa compressive strength and 12 MPa or higher flexural strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grout material having high fluidity, high toughness and excellent seismic resistance, and a method using the grout material.

[0002]

2. Description of the Related Art Conventionally, molded articles made of a hydraulic material such as cement have been widely used.
Attempts have been made to increase toughness.

[0003]

DISCLOSURE OF THE INVENTION The present inventors not only examine the toughness of a molded article, but also reinforce the molded article.
It has been found that it is necessary to impart seismic resistance to grout materials used for repairs and the like. For example, when reinforcing or repairing a pier, a method of installing a formwork on the outer periphery of the pier and pouring grout into the gap between the pier and the formwork to fix the pier is adopted, but the seismic resistance is sufficiently improved For this purpose, it is necessary to consider not only the pier itself but also grout. Until now, grout materials made of cement milk etc. have been widely used, but such grout materials have not been sufficiently studied for seismic resistance etc., and if the amount of water is reduced to improve the performance of hardened grout, The fluidity is reduced, causing a problem in workability. An object of the present invention is to provide a grout material excellent in fluidity and excellent in earthquake resistance and toughness, and a method of using the grout material.

[0004]

According to the present invention, there is provided (1) a grout material containing at least a hydraulic material, a reinforcing fiber and water, wherein at least a part of the reinforcing fiber has a fineness of 8 to 2%.
A grout characterized by being a polyvinyl alcohol-based fiber having a dtex of 70 dtex and a strength of 4 cN / dtex or more, and a compression strength of a standard molded body obtained from the grout material of 45 to 120 MPa, and a bending strength of the standard molded body of 12 MPa or more. (2) A grout material containing at least hydraulic material, reinforcing fiber, aggregate and water, wherein at least a part of the reinforcing fiber is a polyvinyl alcohol fiber having a fineness of 8 to 270 dtex and a strength of 4 cN / dtex or more. And the average particle size of the aggregate is 1000 μm or less,
Further, the compression strength of the standard molded body obtained from the grout material is 45 to 120 MPa, and the bending strength of the standard molded body is 12 M
A grout material characterized by being equal to or higher than Pa, (3)
At least a part of the reinforcing fiber is 55 dtex or more, strength 4
The grout material according to claim 2, wherein the grout material is a polyvinyl alcohol-based fiber having cN / dtex or more and satisfies the following formulas (I) and (II): 2.625-0.0075X≤Y≤3 .375-0.0075X (I) 47Y + 253 ≦ W ≦ 47Y + 293 (II) (where X is the fineness (dtex) of the reinforcing fiber, Y is the hydraulic material / aggregate blending mass ratio (C / S), and W is Unit water volume (kg
/ M ³ ). (4) The hydraulic material is at least one material selected from cement, silica fume, blast furnace slag, fly ash, and metakaolin, and is a hydraulic material mainly composed of cement (1) to (3). (5) A method for reinforcing / repairing a pier using the grout material according to any one of (1) to (4).

[0005]

First, in the present invention, it is necessary to use a specific PVA-based fiber (fiber A) as a reinforcing fiber. If such fibers are not used, it becomes difficult to obtain a cured product having excellent toughness. First, in order to ensure uniform dispersibility of the fibers, the fineness of the fiber A needs to be 8 dtex or more, preferably 10 dtex or more. If the fineness is too small, fiber balls and the like are likely to be generated, and the flowability of the grout material is reduced. Not only does the workability deteriorate, but also the bending strength, toughness, etc. of the cured body become insufficient. In particular, when fibers having a fineness of 55 dtex or more are used, the fluidity of the grout material is unlikely to decrease, so that the same fluidity can be secured even when the water / hydraulic material (mass ratio) is further reduced. When the amount of the water / hydraulic material is reduced, the formation and shrinkage of the cured product are suppressed, and the strength and durability of the cured product are improved. In addition, the workability of the hydraulic material composition is improved, so that a high-performance grout material is used. Is obtained. It is to be noted that, when a reinforcing fiber having a large fineness is used, it is considered that although uniform dispersion is facilitated, "penetration" is likely to occur in the cured product and crack expansion is difficult to suppress, that is, a cured product having high toughness is difficult to obtain. However, by setting the hydraulic material composition to a specific composition, a cured product excellent not only in bending strength but also in toughness can be obtained even when the fineness is relatively large.

However, in order to ensure sufficient adhesion to hydraulic material, to efficiently transmit external stress, to obtain a cured product having high toughness, and to fill a desired portion with grout material without voids. Indicates the fineness of fiber A is 270 dtex
Or less, preferably 250 dtex or less. Larger fineness is preferable from the viewpoint of enhancing the uniform dispersibility of the fiber and obtaining a sufficient reinforcing effect.However, if the fineness is too large, it is difficult to sufficiently exert the fiber strength, and cracks are caused in the cured body due to external stress. When this occurs, the bridging (crosslinked) fibers are easily "peeled out", and even when the hydraulic material composition has a specific composition, it is difficult to suppress the expansion of cracks by the bridging fibers. From the above, it is preferable that the fineness of the fiber A be in the above range. In addition, when the injection / filling area is narrow and clogging (clogging) is likely to occur, it is preferable to reduce the fineness of the fiber, and the smaller the fineness, the more effectively the shrinkage that occurs when the grout material is dried and solidified is effectively suppressed. it can. When the grout material largely suppresses shrinkage, the adherend can be fixed and reinforced more stably.

The fiber length of the fiber may be set according to the fineness, the composition of the grout material, and the like. However, the fiber length is 100 in terms of uniform dispersibility and suppressing clogging at the time of grout material injection.
mm or less, particularly preferably 50 mm or less, and from the viewpoint of bridging effect and the like, the fiber length is preferably 3 mm or more, particularly 5 mm or more, and more preferably 8 mm or more.

From the viewpoint of enhancing the reinforcing effect and obtaining a sufficient bridging effect, the strength of the fiber A should be 4 cN / dtex or more.
It is preferably at least 6 cN / dtex, more preferably 8 cN / dtex.
It is necessary to be cN / dtex or more. If the strength of the fiber is too low, not only the bending strength of the obtained cured product becomes small, but also the bridging fiber that suppresses crack expansion easily breaks, resulting in poor toughness. In addition, since the frictional resistance generated when stress is applied to the cured body is generated in proportion to the surface area of the fiber, the tensile force (frictional resistance) applied to the fiber having a smaller fineness increases. Therefore, it is preferable that the thinner the fiber, the higher the strength. The upper limit of the strength of the fiber A is not particularly limited, but is generally 100 cN / dtex or less. In some cases, a hydrophobic substance such as an epoxy resin, a polyolefin-based resin, a polyethylene oxide resin, or a fluorine-based compound may be added or coated to reduce the affinity for the matrix, and PVA modified with a hydrophobic group may be applied to the surface. You may give. At this time, it is preferable that the adhesion rate to the fiber is about 0.1 to 10% by mass.

Of course, a fiber other than the fiber A may be blended as a reinforcing fiber as long as the effects of the present invention are not impaired. For example, PVA fiber other than fiber A, polyolefin fiber (polypropylene fiber, polyethylene fiber, etc.), acrylic fiber, polyamide fiber (including aramid fiber), polyester fiber (molten liquid crystalline polyester, polyethylene Naphthalate)
Polybenzoxazole fibers, rayon fibers (polynosic rayon fibers, solvent-spun rayon fibers, etc.) and inorganic fibers (glass fibers, steel fibers, etc.) can be used.
Wood pulp or the like can also be used. For the purpose of suppressing drying shrinkage cracks, it is preferable to mix fibers (fiber B) other than fiber A. As the fiber B,
Small diameter fibers, specifically 1-25 dtex, especially 1-7 dtex
It is preferable to mix fibers of dtex, and the fiber length is 1 to 20 m from the viewpoint of uniform dispersibility and shrinkage suppressing effect.
m, especially 2 to 10 mm. If such a fine fiber is blended, the fluidity of the graft material is reduced, so it is preferable to blend a small amount of the graft material.
It is preferred to be 1.3 volume%, especially about 0.06 to 0.8 volume%. The type of the fiber is not particularly limited, but a polyvinyl alcohol-based fiber, an acrylic fiber, or a polyolefin-based fiber (polypropylene-based fiber) excellent in affinity and chemical resistance with a hydraulic material and excellent in dispersibility can be preferably used. .

However, from the viewpoint of efficiently obtaining the effects of the present invention, it is preferable that the main component of the reinforcing fiber to be blended is the fiber A, specifically, 60% by mass or more, particularly 70% by mass or more, and more preferably 90% by mass. It is preferable that the fiber A is at least mass%. The amount of the reinforcing fiber is not particularly limited, but from the viewpoint of sufficiently obtaining the reinforcing effect, 0.1% by volume or more, particularly 0.5% by volume or more, more preferably 0.8% by volume or more. From the viewpoint of ensuring uniform dispersion of the reinforcing fibers and sufficiently exhibiting the reinforcing effect.
It is preferable that the ratio is not more than 3% by volume / formed body, especially 3% by volume / formed body.

A grout material may be prepared by using at least the reinforcing fiber, hydraulic material and water. However,
In order to obtain a hydraulically hardened body having high toughness as well as bending strength, the compression strength of a standard molded body obtained using the grout material must be 120 MPa or less, preferably 100 MPa or less, and more preferably 90 MPa or less. is there. That is, in the compact having a small compressive strength, the first crack is easily generated by the external stress, but the stress generated when the first crack is generated is small. Therefore, even if a crack occurs, the bridging (cross-linking) effect of the reinforcing fiber is exerted to suppress further expansion of the crack, and external stress is transmitted to other fibers before the bridging fiber breaks. Therefore, it becomes possible to bear external stress by a large number of fibers. Therefore, even after the first crack has occurred, the molded body has excellent toughness and earthquake resistance without significantly lowering toughness.

The above fact can be confirmed from the fact that a large number of cracks (multi-cracks) occur in the fracture surface of the cured product when a bending test is performed on the molded product. When the first crack occurs, a bridging (cross-linking) effect by the reinforcing fiber is exerted to suppress the expansion of the crack. Further, a new crack is generated near the first crack, and the bridging effect by the reinforcing fiber also occurs in the crack. Is played. As described above, one crack induces the occurrence of another crack, and the bridging effect of the reinforcing fiber is exerted at each crack, so that the brittle fracture of the hardened body is suppressed, and the crack is excellent in toughness and earthquake resistance. Become. In the cured product with low compressive strength, the cracks formed are very small in width and do not cause fatal damage to the molded product,
Further, since the stress generated in the crack is reduced, the crack expansion can be suppressed by the reinforcing fiber. Therefore, even when external stress is applied, it is possible to greatly "deflect",
Since the hardened grout material is less likely to break and collapse, excellent fixability is exhibited.

On the other hand, when the compression strength of the molded article is too high,
Although cracks due to external stress are unlikely to occur, a first crack is generated when an external stress of a certain value or more is applied, and the stress generated when the first crack is generated increases. Therefore, the bridging fiber present in the crack portion breaks before transmitting the external stress to other fibers, and therefore, even when the above-described fiber A is used, the toughness after the first crack occurs is significantly reduced. It becomes a molded body with low toughness and earthquake resistance. In such a molded article, the width of the first crack is much larger than that of the above-mentioned molded article, and in the molded article, substantially only the first crack is generated and the above-described multi-crack is not generated. In addition, since the smaller the fineness is, the more easily it is broken by the stress at the time of crack generation, when the fineness is less than 55 dtex, the lower the compressive strength of the standard molded body is, the more preferable it is.
It is preferably 0 MPa or less, particularly preferably 65 MPa or less.

Since fibers other than PVA-based fibers have a low affinity with hydraulic materials, they easily "drop out" and do not exhibit a sufficient bridging effect, and effectively transmit external stress. Can not. In addition, even if the PVA fiber is a fiber other than the fiber A specified above, the surface area per fiber is too large or too small, so that the balance between the adhesive force at the contact interface with the matrix and the frictional resistance is lost. In addition, since the bridging effect is easily broken, the ability to transmit external stress becomes insufficient, and a cured product having high toughness cannot be obtained. Therefore, it is necessary to use the fiber A in order to obtain a cured product having high toughness. Therefore, it is possible to use a reinforcing fiber other than the fiber A in combination for the purpose of increasing the mechanical performance (bending strength and the like) of the cured body and for suppressing the drying shrinkage crack, but it increases the toughness of the molded body. Therefore, it is necessary to use the fiber A.

However, if the compressive strength is too low, the matrix itself breaks before the bridging effect is exerted by the reinforcing fibers, so that a molded article having high toughness cannot be obtained. Therefore, the compression strength of the standard molded body needs to be 45 MPa or more, preferably 50 MPa or more, and more preferably 60 MPa or more. The compressive strength of the standard molded body according to the present invention refers to the compressive strength of a hydraulic molded body obtained by a method described in the examples using a grout material. Excellent effects can be obtained by using a grout material in which the compressive strength of the standard molded body falls within the above range. The compression strength of the standard molded body is as follows: hydraulic material, water, reinforcing fiber, aggregate,
It can be adjusted by changing the type and amount of other additives. Further, from the viewpoint of making it difficult to suppress the occurrence of the first crack, the bending strength (MOR) of the standard molded body is set to 12 MPa.
Or more, preferably 13 MPa or more, more preferably 1 MPa or more.
It is necessary to be at least 4 MPa.

The grout material of the present invention can be prepared by kneading at least a hard material, reinforcing fibers and water.
The hydraulic material that can be used in the present invention is not particularly limited,
One or more materials selected from cement, silica fume, blast furnace slag, fly ash, metakaolin,
Further, it is preferably a hydraulic material mainly composed of cement. From the viewpoint of obtaining a cured product having excellent mechanical performance, it is preferable to use cement as a main component, and specifically, Portland cement, particularly ordinary Portland cement, can be suitably used. Above all, those having a lower C ₃ A (calcium aluminate) content are preferred from the viewpoint of increasing the fluidity of the grout material. Of course, sulfate-resistant cement or early-strength cement can be used, but it is preferable to take measures such as increasing the amount of the high-performance AE water reducing agent used since the fluidity of the grout material is reduced.

Further, in the present invention, as a hydraulic material, a part of cement is replaced with at least one material selected from silica fume, blast furnace slag, fly ash and metakaolin, thereby reducing the amount of C ₃ A and reducing the grout material. Fluidity can be increased. In addition, since a pozzolanic reaction occurs instead of the hydration reaction, a decrease in mechanical performance of the cured product can be suppressed, and the corrosion resistance (chlorine, carbonic acid, hydrochloric acid, etc.) of the cured product can be improved. From the point that the hydration reaction proceeds sufficiently to obtain a cured product with excellent toughness, silica fume,
5 to 40% by mass of the total amount of one or more pozzolanic substances selected from blast furnace slag, fly ash and metakaolin
/ Hydraulic material, particularly preferably 5 to 20% by mass / hydraulic material. The amount of the hydraulic material is 750 kg / g in the grout material from the viewpoint of enhancing the mechanical performance of the cured product.
m ³ or more, particularly preferably 800 kg / m ³ or more. From the viewpoint of appropriately reducing the flowability of the grout and the compressive strength of the cured product, it is 1500 kg / m ³ or less, particularly 1400 kg / m ³ or less. It is preferred to be 1300 kg / m ³ or less.

As the water used in the present invention, for example, tap water, river water or the like may be used, and the unit water amount in the grout material is 270 kg / m ³ or more, further 300 kg / m ^3.
As described above, it is particularly preferable to be 320 kg / m ³ or more.
By increasing the unit water amount, the flowability and workability of the grout material can be improved. In general, it is considered that increasing the unit water amount of the grout material is not preferable because the strength of the hydraulic hardened body is reduced.
Even if the unit water amount is increased, sufficient mechanical performance is exhibited because it is reinforced, and since the compressive strength of the cured body is appropriately reduced by increasing the unit water amount, a favorable effect from the viewpoint of toughness is also obtained. can get. However, the preferred unit water amount varies depending on the configuration of the hydraulic material, the reinforcing fibers, and the like constituting the grout material. Therefore, it is preferable to appropriately set the unit water amount according to the compressive strength and the fluidity of the standard molded body. From the viewpoint of workability, the flow value of the grout material is 130 mm or more, further 140 mm or more, and further 150 mm or more, further preferably 160 mm or more, particularly preferably 170 mm or more, and from the viewpoint of the cured body performance, it is 200 mm or less. preferable. By increasing the flow value, the grout material can be injected into a desired site without any gap.

From the viewpoint that the compressive strength and bending strength of the cured product are not unnecessarily reduced, the unit water amount of the grout material is 600 kg / m ³ or less, particularly 500 kg / m ³ or less.
450 kg / m ³ or less, and 420 kg / m ³ or less
m ³ or less. From the same point, it is preferable to set the water / hydraulic material ratio (mass ratio) in the grout material. From the viewpoint of appropriately reducing the compressive strength of the cured product and increasing the fluidity of the grout material, it is preferable to set the ratio to 0.1. It is preferably at least 28, and from the viewpoint that the compressive strength, flexural strength and the like of the cured product are not reduced more than necessary, it is at most 0.42, especially 0.1.
It is preferably set to 40 or less.

Further, an aggregate may be further added. However, it is not preferable to mix coarse aggregate from the viewpoint of effectively transmitting the stress by the reinforcing fiber to obtain a hardened body having high toughness, and an aggregate having an average particle diameter of 1000 μm or less, particularly 500 μm or less, and further 400 μm or less. It is preferable to use (fine aggregate). When an aggregate having a large average particle size is used, defects tend to occur in a transition zone between the aggregate and the hydraulic material, which may cause stress concentration at the time of applying a stress and may cause early fracture. Also, if the diameter of the aggregate is too large, the bridging fiber is likely to `` fall out '', and the hardness of the cured body increases, so that the stress at the time of crack generation increases and the bridging fiber easily breaks, It becomes difficult to obtain a cured product having high toughness. From the viewpoint of improving the mechanical performance of the cured product and the fluidity of the composition, the average particle diameter of the aggregate is preferably 10 μm or more, particularly preferably 20 μm or more.

The type of the aggregate is not particularly limited, but silica sand is preferably used from the viewpoint of chemical and mechanical stability in the hydraulic hardened material. As described above, when the proportion of water in the paste is increased, the fluidity is improved, and the compressive strength of the cured body tends to be reduced. However, the decrease in the compressive strength is suppressed while improving the fluidity by adding silica sand. And an excellent effect can be obtained. Among them, it is preferable to use powdered silica sand having a small average particle diameter or silica sand of No. 5 or more. As the diameter of the silica sand to be compounded increases, the bending strength of the cured body increases and the fluidity of the slurry also improves.However, from the viewpoint of stress transferability, it is preferable to use such minute silica sand, particularly silica sand having a particle size distribution. preferable. In addition,
Silica sand is silicon dioxide 90-97%, aluminum oxide 1-
Those containing 3% and further containing a trace amount of a mineral substance and having a certain degree of particle size distribution are preferably used. The blending amount of the aggregate is preferably about 10 to 50% by mass of the hydraulic material, particularly preferably 20 to 40% by mass. Specifically, in the grout material, 100 kg / m ³ or more, further 200 kg / m ³ or more, In particular, it is preferably at least 300 kg / m ^3, more preferably at least 400 kg / m ^3, and from the viewpoint of fluidity and the like, it is at most 1300 kg / m ³ , especially 110
It is preferably at most 0 kg / m ³ .

Further, other additives may be added.
From the viewpoint of increasing the mechanical performance of the hydraulic molded body without impairing the fluidity of the slurry, it is preferable to add a water reducing agent, particularly a high-performance AE water reducing agent. The applicable water reducing agent is not particularly limited, and examples thereof include high-performance AE water reducing agents such as polycarboxylic acid type, lignin sulfonic acid type, naphthalene sulfonic acid type, and melamine sulfonic acid type. When the amount of water is increased in order to reduce the compressive strength of the cured product or increase the fluidity, a remarkable effect can be obtained by adding such a high-performance AE water reducing agent. Among them, when a polycarboxylic acid-based high-performance AE water reducing agent is used, the dispersibility of the fiber A is remarkably improved, so that the fiber A can be used more preferably. Although the reason for improving the dispersibility of the fiber A is not clear, it is presumed that the linear structure of the water reducing agent improves the dispersion state by bonding the water reducing agent and the fibers by hydrogen bonding of the PVA-based fibers. Specific examples of the polycarboxylic acid-based high-performance AE water reducing agent include, for example, “Tupole” manufactured by Takemoto Yushi, “Darlex Super” manufactured by Denka Grace,
"Leobuild" manufactured by NMB, "Palic" manufactured by Fujisawa Pharmaceutical, "Mighty" manufactured by Kao, "Sunflow" manufactured by Sunflow, and the like. The addition amount of the water reducing agent may be appropriately set depending on other compounding materials and the like. Usually, about 0.5 to 1% by mass is required for the hydraulic material, but an excess of about 2 times or more is added. Specifically, it is preferable to add about 1 to 3% by mass. Specifically, 1 kg / m ³ or more, especially 10 kg / m ³
It is preferably formulated kg / m ³ or more, preferably set to 50 kg / m ³ or less from the viewpoint of the cured product performance.

It is preferable to add a viscosity agent from the viewpoint of uniformly dispersing the components and suppressing the breathing. By adding such a viscosity agent, the viscosity of the grout material increases, and the shearing force between the fibers or between the fibers and the matrix increases, so that the fibers tend to be separated into single fibers, so that an excellent effect is obtained. . In particular, when the amount of water is increased in order to reduce the compressive strength of the molded body, the dispersibility of each material is increased, but the fibers are difficult to be formed into a single fiber. Dispersibility can be significantly improved. Usable viscosity agents are not particularly limited, cellulosic compounds,
Particularly, a cellulose compound having an alkoxy group (at least one or more cellulose compounds selected from methylcellulose, propylmethylcellulose, and hydroxyethylmethylcellulose) is preferably used. Above all,
Cellulose compounds in which a part of the hydroxyl group is substituted with one or more alkoxy groups selected from methoxy, ethoxy, propoxy, hydroxypropoxy, and hydroxyethoxy groups are preferably used, and 1.5 to 1.5 per glucose ring unit. Those obtained by substituting up to 2.5 OH groups with alkoxy groups can be more suitably used.

The amount of the thickening agent to be added may be appropriately determined depending on the fluidity of the grout material, the dispersibility of the fiber, and the like. In general, the viscosity of the grout material increases with a small amount of addition as the degree of polymerization of the viscosity agent increases.
Approximately 000 mPa · s is widely used. In the present invention, it is possible to use such a thickening agent, but in the present invention, it is 2,000 to 8000 mPa · s.
s, especially 3000 to 5000 mPa · s, a more excellent effect is obtained when a viscosity agent is used. Further, the addition amount is preferably about 0.1 to 1% by mass, particularly preferably about 0.3 to 0.5% by mass with respect to the water constituting the grout material. Specifically, it is preferable to add about 0.1 to 10 kg / m ³ .

Such a material may be uniformly mixed to prepare a hydraulic grout material. Method of adding the material, order of addition,
The kneading method is not particularly limited. In addition, fineness 55dtex
When the fiber A is used as a reinforcing material, it is difficult to obtain a hardened body having excellent fluidity and toughness as described above. Therefore, it is preferable to use a grout material having a specific composition. Specifically, it is preferable to use a grout material satisfying the following formula. 2.625-0.0075X ≦ Y ≦ 3.375-0.0075X (I) 47Y + 253 ≦ W ≦ 47Y + 293 (II) In the formula, X is the fineness (dtex) of the reinforcing fiber, and Y is the hydraulic material / aggregate Compounding mass ratio (C / S), W is unit water amount (k
g / m ³ ). Conventionally, the higher the fineness of the fiber, the higher the uniform dispersibility, but the effect of suppressing "cracking" and the expansion of cracks (bridging effect)
However, by adopting the above specific composition, a cured product excellent in bending strength and toughness can be obtained even when the fineness is relatively large. Specifically, since the fluidity of the composition, the mechanical performance, and the adhesiveness and stress conductivity of the fiber and the matrix greatly vary depending on the fineness of the reinforcing fiber, the mixing ratio of the hydraulic material and the aggregate is changed by the reinforcing fiber. It is preferable to determine, and it is more preferable to determine the unit water amount based on the mixing ratio (see FIGS. 1 and 2). In the case where a plurality of reinforcing fibers are used, the composition may be determined using the fineness of the fiber that is the main component of the reinforcing fiber as the fineness of the reinforcing fiber.

Next, the obtained grout material may be injected into a desired portion and cured. The cured product obtained by the present invention is excellent in toughness. For example, when a bending test is performed on a standard molded product obtained from the grout material of the present invention, the deflection at the time of exhibiting bending strength is 10 mm or more, and further 11 mm.
Above, especially 13 mm or more. This is equivalent to several tens of times when reinforced with steel fibers. By using a grout material having a deflection of 10 mm or more, more preferably 11 mm or more, particularly 13 mm or more when the bending strength of the standard molded body is used, the earthquake resistance can be remarkably improved.

The grout material of the present invention can be used in various applications, and can be widely applied, for example, as a grout material for rock, a grout material for concrete repair, a grout material for anchoring method and the like. Above all, it has excellent performance as a grout material for reinforcement and repair of structures requiring earthquake resistance. Above all, structures composed of hydraulic materials, especially piers, columns, beams (large beams, small beams), structural joints, pillars, balcony columns, quays, grout materials for reinforcement and repair of piers, especially reinforcement of piers It is suitable as a grout material for repair. For example, a method may be adopted in which a form is installed on the outer periphery of a structure such as a pier, and a grout material is poured into a gap between the structure and the form to fix the structure.

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to the examples.

[0029]

[Example] [Fineness dtex] The apparent fineness was measured at n = 5 or more by measuring the weight of a given test length of the obtained fibrous material.
The average was determined. In addition, the fineness could not be measured by measuring the weight of a certain yarn length (fine denier fiber) was measured by a vibroscope.

[Fiber strength cN / dtex]
The fibers were allowed to stand for 24 hours in an atmosphere of 65 ° C. and a relative humidity of 65% to adjust the humidity.
The fiber strength was measured in cm / min using an Instron tester “Autograph manufactured by Shimadzu Corporation”. The fiber length is 20
If it is shorter than cm, the maximum length of the sample within the possible range is measured as the grip length. [Average particle size μm] The sieves having smaller mesh sizes were sequentially sieved, and the opening size of the sieve having an integrated passage amount of 50% by mass was defined as the average particle size.

[Flow value mm] A cast iron cylinder having an upper side diameter of 7 cm, a lower side diameter of 10 cm, and a height of 6 cm was used.
cm of the cast iron disk, the cylinder was filled with hydraulic grout, and then the cylinder was gently removed vertically and the grout was allowed to flow onto the disk. Next, after the disk is hit 15 times, the diameter of the grout material spread by the hit or the like is measured in mm. If the spread does not become circular, the average value of the maximum diameter and the minimum diameter is used as the flow value.

[Standard molded body] Hydraulic grout material having a thickness of 1
Pour it into a rectangular mold of 0 mm, 60 mm in width and 240 mm in length and lightly lighten the surface 4-5 times with a hand.
After wrapped in polyethylene sheet at RH and left for 24 hours,
It was demolded and cured in water at 20 ± 1 ° C. for 28 days to produce a standard specimen. [Compressive strength MPa] A cylinder having a diameter of 5 cm and a height of 10 cm was cut out to obtain a sample, which was measured according to JIS A1108-1993 while applying a load at an increasing rate of 0.25 N / mm ² per second. [Bending strength MPa, deflection mm] A three-point bending test was performed under the following conditions, and the bending stress when the maximum load was generated was defined as the bending strength, and the deflection when the bending strength was developed was evaluated by reading. Equipment Shimadzu Autograph AG5000-B Sample Width 60mm, Thickness 10mm, Length 240mm Test speed 0.5mm / min Three-point bending full span 180mm

[Examples 1 to 6, Comparative Examples 1 to 6] Ordinary Portland cement (manufactured by Taiheiyo Cement), silica sand, and methylcellulose ("High-Metroze 90SH4000" manufactured by Shin-Etsu Chemical Co., Ltd.) were added to an omni mixer. The mixture was kneaded for 1 minute, and water and a high-performance AE water reducing agent (“Reobuild SP-8N” manufactured by NMB) were added and kneaded for 30 seconds. Then, after kneading, kneading was further performed for 90 seconds, reinforcing fibers were added, and kneading was performed for 30 seconds. After kneading, kneading was further performed for 90 seconds to prepare a hydraulic grout material having the composition shown in Table 1. A standard molded body was manufactured from the obtained hydraulic grout material, and the performance was evaluated. Table 1 shows the results. The silica sand used was “Toyosilica Sand” manufactured by Toyo Materan Co., Ltd., with SiO ₂ = 93.7% and Al ₂ O ₃ = 1.8.
%, Fe ₂ O ₃ = 0.5%. The average particle size of No. 7 silica sand is 69 μm, the average particle size of No. 6.5 silica sand is 180 μm, the average particle size of No. 6 silica sand is 188 μm,
The average particle size of No. 5 silica sand is 300 μm. Further, silica fume is manufactured by Union Chemical Co., Ltd., fly ash is manufactured by Kandenka Kogyo Co., Ltd., SiO ₂ = 53.4%, Al ₂ O
₃ = 26.0% and a specific surface area of 3000 cm ² / g were used. In addition, the compounding amount of each material other than the fibers in Table 1 is the compounding kg per 1 m ³ .

[0034]

[Table 1]

[Examples 7 to 12] When a mold was formed around an existing concrete pillar using plywood with a clearance of 2 cm, and the grout material obtained in Examples 1 to 6 was injected, it was uniformly filled in the voids. The grout material could be filled, and the cured product had excellent bending strength and toughness.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a preferred range of hydraulic material / aggregate (C / S) with respect to the fineness of reinforcing fibers in a grout material of the present invention.

FIG. 2 is a schematic diagram showing a preferable range of a unit water amount (Kg / m ³ ) with respect to a hydraulic material / aggregate (C / S) in the grout material of the present invention.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C04B 16:06 C04B 16:06 B 22:06 22:06 A 18:14 18:14 C 18:08 18 : 08 Z 14:10) 14:10) Z 103: 30 103: 30 111: 70 111: 70 C09K 103: 00 C09K 103: 00 (72) Inventor Hisashi Suemori 1-2-1 Kaigandori, Okayama City, Okayama Prefecture No. Kuraray Co., Ltd. (72) Inventor Hideki Hojo 1-12-39 Umeda, Kita-ku, Osaka F-term in Kuraray Co., Ltd. 4G012 PA06 PA24 PA27 PA29 PB03 PB04 PC01 PC12 4H026 CA01 CA05 CA06 CB08 CC06

Claims (5)

[Claims] 1. A grout material containing at least a hydraulic material, reinforcing fibers and water, wherein at least a part of the reinforcing fibers has a fineness of 8 to 270 dtex and a strength of 4 cN / dte.
x or more, and the standard molded body obtained from the grout material has a compressive strength of 45 to 1
A grout material characterized by having a bending strength of 20 MPa and a standard molded body of 12 MPa or more. 2. A grout material containing at least hydraulic material, reinforcing fiber, aggregate and water, wherein at least a part of the reinforcing fiber has a fineness of 8 to 270 dtex and a strength of 4 cN /
dtex or more polyvinyl alcohol-based fiber, and the average particle size of the aggregate is 1000 μm or less, and the standard molded body obtained from the grout material has a compressive strength of 45 to 45.
A grout material characterized by having a bending strength of 120 MPa and a standard molded body of 12 MPa or more. 3. A method in which at least a part of the reinforcing fibers is 55 dte.
The grout material according to claim 2, wherein the grout material is a polyvinyl alcohol-based fiber having a strength of at least x and a strength of at least 4 cN / dtex, and satisfying the following formulas (I) and (II). 2.625-0.0075X ≦ Y ≦ 3.375-0.0075X (I) 47Y + 253 ≦ W ≦ 47Y + 293 (II) (where X is the fineness (dtex) of the reinforcing fiber, and Y is the hydraulic material / aggregate) Compounding mass ratio (C / S), W is unit water volume (kg
/ M ³ ). ) 4. The hydraulic material is at least one material selected from cement, silica fume, blast furnace slag, fly ash, and metakaolin, and is a hydraulic material containing cement as a main component. The grout material according to any one of the above. 5. A method for reinforcing and repairing a pier, comprising using the grout material according to any one of claims 1 to 4.