JP2000240297A - Thickening and reinforcing structure of concrete structure and its construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thickening and reinforcing structure of a concrete structure firmly reinforcing the concrete structure and repairing cracks, etc., and to provide a construction method for the thickening and reinforcing structure of the concrete structure facilitating the construction of the thickening and reinforcing structure for the concrete structure at low cost and being superior in landscape. SOLUTION: This is a thickening and reinforcing structure for a concrete structure having a thickening and reinforcing layer 4 formed at least in a part of a surface of the concrete structure, the thickening and reinforcing layer is constituted of at least either one layer of a layer containing cement, amorphous silica, aggregate, and synthetic resin or a layer containing cement, amorphous silica, aggregate synthetic resin, and fiber material. It is preferably set to three layers or more by using the reinforced fiber layer for an intermediate layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to thickening and reinforcement of a concrete structure, for example, to prevent the strength of a concrete floor slab from being reduced due to an increase in traffic or vehicle load, thereby preventing the concrete slab from being broken. TECHNICAL FIELD The present invention relates to a thickening reinforcement structure for a concrete structure such as a bridge and a construction method thereof.

[0002]

2. Description of the Related Art The design live load of a road bridge was newly reviewed in a road bridge specification revised as of February 1994, and the design live load specified in the previous road bridge specification was revised. The weight and traffic volume of the underlying vehicles have increased significantly.
For this reason, the strength of each part constituting the road bridge is insufficient, and in particular, most of the concrete slabs of the road bridge that directly receive the wheel load of the vehicle are in a state where the thickness and the amount of reinforcing steel are insufficient, and the fatigue of concrete and reinforcing steel is reduced. The degree of damage of the steel has rapidly increased. As a countermeasure, there is a need for a technique for compensating for the insufficient strength of the concrete slab of the bridge without hindering the traffic of vehicles.

Conventionally, the following methods have been known as methods for compensating for insufficient strength of a concrete slab of a bridge without hindering traffic of vehicles.

(1) A hole is made in the lower surface of the concrete slab, a bolt is inserted into the hole and fixed with an adhesive, and a steel plate is secured to the bolt while securing a predetermined gap between the slab and the lower surface of the concrete slab. After mounting and fixing, the gap between the lower surface of the concrete slab and the steel plate is injected and filled with an adhesive, for example, epoxy resin, to bond and integrate the steel plate with the concrete slab.

(2) Drill a hole in the lower surface of the concrete floor slab,
After inserting a bolt into this hole and fixing it with adhesive, attaching a reinforcing bar to this bolt and fixing it, a high-strength mortar such as non-shrink mortar or resin mortar is integrated with this reinforcing bar under the concrete floor slab. A method of thickening the bottom surface of the concrete slab by stacking it on top.

(3) An upper surface thickening method in which a rapidly hardening concrete (SFC) mixed with steel fiber is poured into the upper surface of the floor slab to form a reinforcing layer.

[0007]

However, a hole is made in the existing concrete slab of the above (1), a bolt is inserted into the hole and fixed with an adhesive, and the bolt is used as an anchor with a high-tensile material. According to the conventional method of attaching and fixing a steel plate or a reinforcing steel bar, it is necessary to make a number of bolt holes in a concrete slab. However, drilling a large number of bolt holes in a concrete floor slab partly damages the main body of the floor slab. Drilling holes for bolts may cause water leakage from the bridge surface. In addition, unevenness such as bolts is exposed on the back of the bridge, which hinders the view from the underside of the bridge, such as viaducts, and the use of heavy materials such as steel plates and reinforcing steel bars increases the overall dead load of the bridge. In some cases, the foundation and other parts may be adversely affected. Furthermore, this conventional method often involves work in difficult positions, such as drilling bolts from the underside of the floor slab and attaching and welding steel plates and reinforcing bars, and the work process is complicated, resulting in poor work efficiency. There is also a problem that the construction period is long.

Further, according to the steel plate bonding method (2), the lower surface of the floor slab is covered with the steel plate.
Even if damage to the floor slab progresses due to poor construction or deterioration over time, it is difficult to detect the damage, and it is necessary to periodically apply repair painting to prevent corrosion of the steel sheet, so it takes time to maintain and manage after construction Have issues.

On the other hand, the upper surface thickening method using SFC of the above (3) has the following problems. a) The cured SFC has poor water barrier and, as in recent years,
When a water-permeable pavement is provided so that water does not collect on the road surface in rainy weather, rainwater permeates through the SFC layer and penetrates into the inside to accelerate deterioration of the base. In order to prevent this, a waterproof layer, specifically, a waterproof sheet or a waterproof coating layer is indispensable, and extra work is required.

B) Since the SFC layer has some difficulty in strength, it is necessary to apply a thickness of at least 40 to 50 mm in order to exert a sufficient reinforcing effect. As a general standard, the thickened layer and the pavement road surface are 80 mm in total, so the asphalt layer is 30 to 40 mm,
It is necessary to use an expensive grade in terms of durability, resulting in high cost.

C) SFC itself is expensive, and when combined with the above a) and b), the method becomes expensive as a whole.

D) The composition for construction has a high fluidity and is difficult to construct on the lower surface of the building to be reinforced.

The present invention has been proposed in view of the above-mentioned problems of the conventional construction method, and an object of the present invention is to provide a concrete structure for reinforcing concrete structures and repairing cracks and the like. The purpose of the present invention is to provide a thickening reinforcement structure for a concrete structure, and to easily construct a thickening reinforcement structure for a concrete structure. There is also to provide a construction method of the structure.

[0014]

SUMMARY OF THE INVENTION The present invention relates to a thickening reinforcing structure for a concrete structure having a thickening reinforcing layer formed on at least a part of the surface of the concrete structure, wherein the thickening reinforcing layer comprises cement, It is characterized by comprising at least one of a layer containing amorphous silica, aggregate and synthetic resin, and a layer containing cement, amorphous silica, aggregate, synthetic resin and fiber material.

The portion where the thickening reinforcing layer is provided is, for example, a bridge, an upper surface, a lower surface, a pier and the like of a concrete slab.
The underside of the floor slab and the pier have exposed concrete surfaces and can be constructed as is. The upper surface of the floor slab is paved with asphalt or the like, and at the time of this repair, when the asphalt is removed, or for a newly constructed one, before the pavement, the thickening reinforcement layer of the present invention is applied. . The thickened reinforcing layer may be applied to the entire surface of the reinforcing portion, or may be applied only to a portion that particularly needs to be reinforced. In particular, when constructed on the upper surface of the floor slab, water penetrating the concrete structure from cracks in the paving agent such as asphalt is blocked by a cement, a thickening reinforcing layer formed by a composition including amorphous silica, etc. The life of the structure can be greatly extended.

[0016] Amorphous silica is amorphous silica, which is produced by extracting and processing silica from 80% (average approximate value) contained in volcanic minerals, or pulverizing or refining minerals. It is a compound produced as a by-product such as silica fume at the time, and also reacts with a reactive inorganic compound such as cement under alkaline conditions to produce ettrine guides (needle crystals). These crystals penetrate into the micropores of the substrate by a synergistic effect with the specially modified polymer to form a tough film, and also chemically react with and bond with concrete, improving the adhesive strength with the substrate and improving the adhesion of the substrate. It is said to have the effect of exerting the effect of reinforcing physical strength.

The thickening reinforcing layer according to the present invention comprises cement,
A layer containing amorphous silica, aggregate, and synthetic resin, or at least one layer of cement, amorphous silica, aggregate, synthetic resin, and a layer containing fiber material. It is possible to form a thickened reinforcing layer having no water permeability due to the effect presumed to be a composite effect including the effect.

That is, the thickened reinforcing layer of the present invention can be firmly integrated with a concrete structure without using other adhesives due to the above excellent adhesive strength and physical strength exhibited by the composition. It has the effect of enhancing the bending stress and the punching shear stress of the concrete structure, and also has waterproofness.

Although cement itself hardens and exhibits a reinforcing effect, the cement exhibits more excellent adhesive strength and reinforcing properties due to the reaction with the amorphous silica as described above.

The aggregate increases the strength of the thickened reinforcing layer, reduces distortion due to curing shrinkage, and contributes to prevention of cracks. The synthetic resin is a resin component of the synthetic resin emulsion, and is presumed to exhibit an effect of increasing the flexibility and strength of the thickened reinforcing layer.

The thickening reinforcing layer of the present invention has high strength,
A sufficient reinforcing effect is exhibited even when the construction thickness is reduced by about 10 mm from the above known SFC to 30 to 40 mm. Therefore, the thickness of asphalt pavement is
mm can be set to 40 to 50 mm, and low-cost asphalt can be used. Furthermore, the thickening reinforcement layer itself of the present invention is also relatively inexpensive, and even when the thickening reinforcement layer is provided on the upper surface of the concrete slab, the construction of a waterproof layer is not required unlike SFC, and the thickening reinforcement structure is not required. As a whole, a lower price than before can be realized.

The thickness of the thickened reinforcing layer is arbitrarily set according to the required reinforcing performance, but can be made thinner than when SFC is used.

As the material constituting the thickening reinforcing layer of the present invention, it is preferable to use a fiber material in addition to cement, amorphous silica, aggregate, and synthetic resin. The physical strength, especially the tensile strength, of the reinforcing layer can be greatly improved, and a stronger reinforcing effect can be obtained. The same reinforcing effect can be obtained by designing the thickness of the thickened reinforcing layer to be thin.

The thickening reinforcing layer in the thickening reinforcing structure of the present invention may be a single layer or a laminate of two or more layers. In the case of lamination, cement, amorphous silica, aggregate, and even a layer of a layer that does not contain a fiber material in a component containing a synthetic resin, even a layer of a layer that does not contain a fiber material, It may be a laminate of layers including a fiber material. These are determined in consideration of the place where the thickened reinforcing layer is constructed, the required strength, and the like.

When two or more layers are laminated, the thickening reinforcing layer further provided with a reinforcing fiber layer as an intermediate layer means that the physical strength of the thickening reinforcing layer is greatly improved and the reinforcing effect of the base is improved. Is large, which is a particularly preferable embodiment. Two or more reinforcing fiber layers are provided as necessary.

The present invention is a method for constructing a thickening reinforcing structure for a concrete structure, wherein the thickening reinforcing layer is formed on at least a part of the surface of the concrete structure, wherein the thickening reinforcing layer is made of cement, amorphous silica, or the like. , Aggregate, and a composition including a synthetic resin emulsion, cement, amorphous silica, aggregate, synthetic resin emulsion, and at least one of a composition including a fiber material, is applied to the surface of the concrete structure. is there. Each of the layers may be formed first. In the present construction method, a base treatment such as a primer treatment is not particularly required.

[0027] In the method of constructing the thickening reinforcement structure,
The thickening reinforcing layer, cement, amorphous silica, aggregate, and a composition containing a synthetic resin emulsion, cement, amorphous silica, aggregate, synthetic resin emulsion, and a composition containing a fiber material, alternately applied It is preferable to form at least a two-layer structure.

In the above-described method of applying the thickening reinforcing layer,
It is preferable to form a thickened reinforcing layer having at least a three-layer structure by further applying a reinforcing fiber layer as an intermediate layer.

The material used for the reinforcing fiber layer is a woven or non-woven fabric made of the same long fiber material as the above-mentioned fiber material, and may be a coarse-grained material such as gauze. By providing such a reinforcing fiber layer between the thickened reinforcing layers formed by the composition containing amorphous silica as a main component, the same or more than the case where the fiber material is mixed into the composition, sufficient A reinforcing effect can be obtained.
The reinforcing fiber layer may be manufactured using either a monofilament or a multifilament.

As the fiber material to be mixed into the composition containing the cement or the like for forming the thickened reinforcing layer, inorganic fibers, metal fibers, carbon fibers, and organic fibers can be used. When such a fiber material is used by being mixed with a composition containing cement, amorphous silica, aggregate or the like to be applied, in order to obtain a sufficient effect of addition, the average fiber length is 0.03 mm or more and the aspect ratio is Use 5 or more.

The above composition is mixed and mixed with an aggregate such as cement, amorphous silica and silica sand, a synthetic resin emulsion, a fibrous material to be used as required, and a solvent such as water for imparting fluidity. It is obtained as a paint-like or putty-like construction composition, and is sprayed onto the surface of a concrete structure, applied by a general painting method such as ironing, construction, drying, reaction, and curing. By doing so, the thickened reinforcing layer of the present invention is obtained.

In particular, the construction composition for forming the thickened reinforcing layer of the present invention may be produced by a method involving collision such as spraying or a method of applying an impact external force such as rolling pressure or vibration during finishing after ironing or pouring. It is particularly preferable from the viewpoints of rapid curing and development of strength.

Another feature of the present invention is that the above-mentioned construction composition is used for a thickening reinforcement structure of a concrete structure, and the main work on site at the time of construction is to spray the construction composition as a paint. In this case, only construction work by attaching or ironing is performed, and construction in a severe environment such as when thickening reinforcement is applied to the lower surface of a concrete floor slab of a bridge can be easily and simply performed.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION The embodiment of the present invention will be described below with reference to a case in which thickening reinforcement is applied to the lower surface of a concrete slab of a general bridge such as a highway.

FIG. 1 is a sectional view showing the structure of a general bridge such as an expressway. A plurality of steel bridge girders 1 are constructed on a pier 6 via a shoe 5 and a concrete slab 2 and The pavement 3 is constructed and configured. The pavement layer 3 becomes the road surface of the road, and vehicles and the like pass through. The wheel load of the passing vehicle is loaded on the concrete slab 2 via the pavement 3. The concrete slab 2 constitutes a beam structure supported by a plurality of steel bridge girders 1, and generates various stresses such as bending and punching shear due to wheel loads.

In the embodiment of the present invention, as shown in FIG. 1, a thickening reinforcement layer 4 shown in FIGS. Thus, the lower surface of the concrete floor slab 2 is thickened and reinforced.

The thickening reinforcing layer 4 shown in FIGS. 2 to 8 will be described below.

The thickening reinforcing layer 4 shown in FIG. 2 is formed by the coating a of the working composition, and is about 20 m as an example.
m thickness.

The thickening reinforcing layer 4 shown in FIG. 3 is formed by a coating film b of a working composition containing carbon fibers.
As a specific example, the thickened reinforcing layer 4 having a thickness of about 30 mm is used for the concrete floor slab 2 without using an adhesive due to its adhesion strength and tensile strength reinforced by carbon fiber.
And the strength of the concrete floor slab 2 is sufficiently enhanced even with this thickness.

The thickening reinforcing layer 4 shown in FIG. 4 is made of a coating c of a working composition mixed with a metal fiber, micro steel fiber or the like.
And is constructed to a thickness of about 30 mm as an example. Even with this thickness, the bending strength and the punching shear strength of the concrete slab 2 are sufficiently enhanced as in the case of FIG.

The thickening reinforcing layer 4 shown in FIG. 5 is formed into a two-layer structure by applying a coating a of the working composition containing no fiber material and a coating b of the working composition mixed with carbon fibers. And each layer thickness is about 15mm and total about 30m
An example in which the thickness is m is shown. FIG. 6 shows a thickening reinforcing layer having a two-layer structure in which a coating a of the construction composition containing no fiber material and a coating c of the construction composition mixed with metal fibers are each applied to a thickness of 15 mm. Was. In the thickening reinforcing layer 4 shown in FIGS. 5 and 6, a coating a of the construction composition containing no fiber material and a coating b or c of the construction composition mixed with the fiber material are formed in reverse order. The same effect can be obtained in this case. A, b, c
May be applied in a thickness of 10 mm each to form a three-layer structure.

The thickening reinforcing layer 4 shown in FIG. 7 has a three-layer structure in which a reinforcing fiber layer d such as a nonwoven fabric using carbon fibers is sandwiched between upper and lower coating films a of the working composition containing no fiber material. The upper and lower coatings a are formed to a total thickness of about 30 mm by about 15 mm each. Due to the adhesive strength of the construction composition and the physical strength enhanced by the reinforcing fiber layer d using carbon fibers provided in the middle, the concrete composition is firmly integrated with the concrete floor slab 2 without using an adhesive. The bending strength and the punching shear strength of the floor slab 2 are reinforced and strengthened.

The thickening reinforcing layer 4 shown in FIG.
Is formed in a three-layer structure with a reinforcing fiber layer e of a nonwoven fabric or the like made of a fiber material interposed therebetween, and the upper and lower coatings a are formed to a total thickness of about 30 mm by about 15 mm each. .

FIG. 9 shows an example in which a thickening reinforcing layer 4 is provided on the upper surface of the concrete floor slab 2. Also in this example, the bending strength and the punching shear strength of the concrete floor slab 2 are reinforced and strengthened. Assuming that the thickening reinforcing layer 4 is 40 mm, the construction of a 40 mm general low-cost asphalt layer is sufficient, and a low-cost reinforcing road surface is formed as a whole.

Next, a method of constructing the thickening reinforcement structure of the present invention applied to the concrete floor slab 2 of a general bridge such as a highway will be described with reference to FIGS.

[Working method 1] FIG. 2 shows a single or composite formed by a working composition containing no fiber material or a working composition in which carbon fibers or metal fibers are mixed.
First, the work scaffold 7 is constructed by the scaffold pipe 8, the scaffold plate 9, the suspension chain 10 and the like prior to the execution of the thickening reinforcement layer 4 shown in FIGS. Between the upper surface and the lower surface of the concrete floor slab 2 of the bridge, a protective sheet 11 for preventing scattering of the thickening reinforcing material and curing the thickening reinforcing layer 4 is provided. And
Dirt, dust, free lime and the like attached to the lower surface of the concrete floor slab 2 of the bridge are removed by sand blasting, CO ₂ blasting, wire brush, or the like, and the cracking or unevenness of the concrete, preferably containing no fiber material, is a construction composition. It is repaired by, for example, to prepare for the construction of the thickened reinforcing layer 4.

When the preparation is completed, the construction of the thickening reinforcing layer 4 is started. That is, after the construction composition containing no fiber material or the construction composition obtained by mixing the carbon fiber with the composition is mixed and stirred on the ground or the like, as shown in FIG. It is used to pressurize it to an enforcement place, spray it to a predetermined portion with a spray gun 13, and, as shown in FIG. The reinforcing layer 4 is formed.

However, the thickened reinforcing layer 4 formed in a two-layer structure shown in FIG. 5 or FIG. 6 has an adhesion area between each coating by a spiral roller or the like before the composition of each coating is dried. Rolling is performed while increasing the size, and the final film is flattened by rolling with a flat roller or the like before the composition is dried.

[Working method 2] Thickened reinforcing layers 4 shown in FIG. 7 or FIG. 8 formed in at least three layers with a cloth using carbon fibers or reinforcing fibers sandwiched between upper and lower working compositions. First, prior to the application of the thickening reinforcement layer 4, the work scaffold 7 is constructed with the scaffold pipe 8, the scaffold plate 9, the suspension chain 10, etc., and the upper surface of the work scaffold 7 and the lower surface of the concrete floor slab 2 of the bridge are constructed. In between, a protective sheet 11 for preventing scattering of the thickening reinforcing material and curing the thickening reinforcing layer 4 is provided. And
Adhering to the lower surface of the concrete slab 2 of a bridge dirt and dust and free lime and removed by sandblasting or CO ₂ blasting and wire brush, increasing to repair cracks and unevenness of the concrete as in the case of construction methods 1 Prepare for the construction of the thick reinforcing layer 4.

When the preparation is completed, the construction of the thickening reinforcing layer 4 is started. That is, after the composition for construction containing no fiber material is mixed and agitated on the ground or the like, as shown in FIG. As shown in FIG. 10, before the composition for construction is dried, a reinforcing fiber layer using a fiber such as carbon fiber is rolled by a rolling roller 14 and shaped while being bonded. Thereafter, the application composition is sprayed again with the spray gun 13 so as to sandwich the reinforcing fiber layer d, and the composition is flattened by rolling with the roller 14 before the application composition is dried. The thickening reinforcing layer 4 is formed.

In the above-mentioned construction methods 1 and 2, the composition for construction is sprayed on a predetermined portion with the spray gun 13, but it is also possible to apply iron on a predetermined portion with an iron.

Although the present invention has been described with reference to the case where the thickening reinforcement is applied to the lower surface of the concrete floor slab 2 of the bridge shown in FIG. 1, the present invention is applied to each of the bridges other than the bridge shown in FIG. Can be applied to the upper surface of the concrete floor slab 2 of the bridge, and can also be applied to the reinforcement of the beams, piers, wall surfaces, etc. of concrete structures other than the bridge. For example, when constructing on the upper surface of a concrete floor slab, a fluid of the composition for construction may be poured on the floor, spread with a scraper or the like, and shaped with a compaction roller.

In the present invention, as the cement used as the component for forming the thickening reinforcing layer, cements such as air-hardened cement, hydraulic cement and the like (Kyoritsu Kagaku Dictionary) can be used. In particular, generally used cements such as Portland cement and alumina cement can be used. In consideration of the appearance, it is particularly preferable to use white cement because it can be colored freely.

As the amorphous silica used in the present invention, activated shirasu produced by the method described in JP-A-4-182338, silica fume generated in the step of refining minerals, and the like can be used without limitation. .

As the aggregate, natural stone powder, porcelain sand, quartz sand,
Sand or the like can be used, and fine particles having a roughness of 10 mesh or more are suitable. It is also a preferred embodiment to use a mixture of coarse and fine materials. Specifically, 10
The use of a mixture of 20 mesh coarse, medium coarse of about 20 to 60 mesh, and fine to fine powder of 60 mesh or more is excellent in reinforcement performance and ease of construction. Particularly preferred is that a composition can be obtained.

The silica sand containing at least 90% of SiO ₂ may be any of those generally called silica sand.

As the fiber material to be mixed into the working composition of the present invention, fibers having a relatively short fiber length (including whiskers) having a reinforcing effect can be used. For example, fibers such as polyester and nylon, and organic fibers such as aramid fiber can be used. Fibers of inorganic materials such as short fibers, potassium titanate whiskers (trade name: Tismo Otsuka Chemical Co., Ltd.), glass fibers, wollastonite, and metal fibers, such as brass and iron produced by chatter vibration cutting And short fibers (made by Tokyo Steel) of aluminum, stainless steel, etc. can be used. Also, short carbon fibers (chop strand, milled fiber) can be used, and PAN-based carbon fibers and pitch-based carbon fibers obtained by treating fibers such as acrylonitrile fibers can be used. The use of pitch-based carbon fibers is preferred from the viewpoint of cost. As is known in the art of composite materials, these fibers can have an aspect ratio of 5 or more and a fiber length of 0.3 mm or more. In consideration of reinforcing properties and workability, the fiber diameter is preferably 10-500μ
m, average fiber length is 0.5 to 100 mm.

The synthetic resin material added in the present invention is added in a small amount as long as it does not affect the weather resistance. Materials that can be used are aqueous solutions or aqueous dispersions (generally called resin emulsions), for example, latexes such as acrylic / styrene copolymer emulsions, acrylic resin emulsions, polyurethane emulsions, and natural rubber latex. Particularly, a reactive epoxy emulsion, an acrylic resin emulsion, an acrylic / silicone emulsion and the like are preferable. Mixing two or more of these can be used without any problem. In particular, the minimum film formation temperature is 5 ° C or higher,
More preferably, an acrylic / styrene copolymer emulsion at room temperature or higher, or another modified acrylic resin emulsion, which is a self-crosslinking resin emulsion, has a strong effect of increasing the strength of the thickened reinforcing layer, and is therefore preferable.

The mixing ratio of these materials is expressed by weight ratio:
When the cement is 100, the aggregate is 800 to 240.
0, amorphous silica is preferably in the range of 5 to 50, and synthetic resin emulsion is in the range of about 40 to 400 in terms of resin. The amount of the synthetic resin as the organic binder is preferably 20% by weight or less as a solid content based on the total inorganic content including fibers. If it is more than this, the weather resistance decreases and the adhesive strength also decreases.

The fibrous material is preferably added in a range of 200 parts by weight or less based on 100 parts by weight of cement.

When these materials are mixed, various dispersants, wetting agents, surfactants,
In addition, the viscosity of the paint, a water reducing agent for adjusting the solid content concentration,
There is no problem in adding a thickener and an antifoaming agent. Examples of the thickener include, for example, High Metros (Shin-Etsu Chemical Co., Ltd.)
Inorganic materials such as hydroxyethylcellulose (manufactured by Daicel Chemical Industries, Ltd.) and carboxymethylcellulose (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

The working composition is a mixture of all the components, but in the distribution stage, the first composition in which an aggregate such as cement, amorphous silica, silica sand or the like is mixed as an essential component in order to suppress the reaction. Product and an organic binder, a two-component system comprising a necessary additive as an essential component, and mixed using a stirrer such as a hand mixer before use,
It is preferable to construct. In this case, water may be added within 100 parts depending on workability.

When the composition for application is applied as a paint, it is preferable to apply a commonly used mortar gun or ricin gun, and use a multi-head gun of two or more guns and discharge another material from each gun head. Is also good. For example, the two components can be discharged from different gun heads and adhered while mixing.

[0064]

The following is a description of the compounding and manufacturing method of the working composition used in the present invention. [Example 1] (The compounding amount is shown in parts by weight.) Compositions 1A and 1B having the compositions shown in Tables 1 and 2 below were prepared.

[Table 1]

[Table 2] As the styrene acrylic emulsion, a self-crosslinking emulsion having an MFT of 30 ° C. and a glass transition temperature of a resin of 10 ° C. was used.

[Evaluation] (Preparation of Sample) [1] Coating Method The composition 1A and the composition 1B were simultaneously sprayed using a multi-head gun to form a thickened reinforcing layer as a coating layer. The nozzle diameter of the gun was 8 mm, the spray pressure was 392 kPa, the spray amount was 2.3 kg / m ² , and the predetermined thickness was obtained by recoating.

[2] Sample of Thickening Reinforcement Layer itself A coating film layer of about 5 mm was formed on a 5 mm thick polypropylene plate, and after curing, peeled off to obtain a sample of the thickening reinforcement layer itself. Using this sample, specific gravity, bending strength, compression strength, and tensile strength were measured.

[3] Preparation of Reinforcement Sample A JIS A 5304 (1988) pavement concrete flat plate N-300 (300 × 300 × t60) was used as a substrate.
mm) under the above-mentioned conditions three times to form a thickened reinforcing layer having a thickness of about 7 mm.

The acid resistance evaluation sample for steel was
A similar sample was made using a 300 × 300 × t5 mm steel plate.

Curing conditions are as follows: 20 ° C. ± 2 ° C., humidity 65 ± 1.
0% for 7 days. The reinforced sample was used for evaluations other than the above items.

[4] Measurement ・ Bending strength: JIS A 6909 (1995) conformity ・ Compression strength: JIS A 6909 (1995) conformity ・ Tensile strength: JIS A 6909 (1995) conformity ・ Adhesive strength to concrete: JIS A 6909 ( 1
995) Evaluation of acid resistance: The coating film surface was brought into contact with diluted sulfuric acid having a pH of 1 and the state after 2500 hours was visually observed.

Accelerated weather resistance: Irradiation was performed for 4000 hours using a carbon arc sunshine weather meter, and the surface after the test was visually evaluated.

-Neutralization inhibitory property: Using a CO ₂ environmental tester, a CO ₂ concentration of 5%, 20 ° C. and 60% RH conditions are 30
A day accelerated neutralization test was performed. After the test period, the sample is taken out of the CO ₂ environmental testing machine, and the center is split. A 1% phenolphthalein solution is sprayed on the split surface, neutralization is determined by the color reaction, and the depth of six neutralized portions of one sample is measured with a vernier caliper to 0.5 mm. The average of the 12 measurements of the two samples was taken as the neutralization depth.

Water permeability: JIS A 6909 (199
5) Compliant ・ Impact resistance: The sample is held horizontally by the whole surface support method on sand specified in JIS A1421 (1981).
Spherical weight W ₂ -1000 (1042g) on the surface of the thickened reinforcing layer
Was repeatedly dropped from the height of 2 m to the same place, and evaluated by the number of times cracks occurred.

[0074]

[Table 3] The evaluation of the impact resistance was carried out for five samples of Example 1, and for comparison, three paving concrete plates N-300 without the thickening reinforcing layer were also measured for comparison. The evaluation results show that the sample of Example 1 has an average of 1
At 2.2 (max. 14, min. 10) times, cracks were observed in the thickened reinforcing layer. On the other hand, in the comparative sample, cracks occurred on the substrate at an average of 3.7 (max. 4, min. 3).

From Table 3 and the results of the impact resistance test, the compressive strength, adhesion strength, tensile strength, impact resistance, etc., of the construction composition required for the upper or lower thickened reinforcing structure of the concrete floor slab 2 of the bridge are shown. It can be seen that is excellent in the physical properties of. Accordingly, by using the construction composition as the thickening reinforcement layer 4 for reinforcing the concrete floor slab 2 of the bridge on the lower surface, the adhesive is used due to the adhesive strength and tensile strength of the construction composition as its characteristics. , The thickening reinforcing layer 4 can be firmly integrated with the concrete slab 2 and the bending strength and the punching shear strength of the concrete slab 2 are enhanced. Also accelerated weather resistance,
It is also excellent in acid resistance, neutralization inhibiting properties and water permeability, and also provides protection performance of the substrate.

Example 2 Composition A of Example 1 was combined with carbon fiber having a fiber length of 5 mm (Donacarbo S-230,
(Donack Co., Ltd.) was added and mixed to obtain a composition having the same composition as in Example 1 except that a mixture was used, and used as a paint-like construction composition.

When the concrete layer was applied to a concrete plate and evaluated, a reinforcing effect equivalent to that of Example 1 was obtained even with a reinforcing layer thinner than that of Example 1.

[0078]

As described above, according to the present invention,
By increasing and reinforcing the surface of concrete structures such as bridges with the construction composition, ethrin guides (needle-shaped crystals) generated by the reaction of cement and amorphous silica with the alkali of existing concrete It penetrates into the fine pores of concrete and causes a chemical reaction with concrete to form a tough coating, so it has excellent adhesive strength to concrete structures and increases the physical strength of concrete structures. A thickened reinforcing layer with characteristics can be obtained, and it is possible to strongly reinforce concrete structures without using heavy materials such as steel plates and reinforcing bars as in the past, and with existing concrete without using an adhesive. Since the thickened reinforcing layer is structurally firmly integrated, there is no aging.

Further, by using a construction composition containing no fiber material or a construction composition mixed with a fiber material to increase the thickness of the surface of a concrete structure, a main work at the site is performed by the above construction work. Only construction work such as spraying or troweling of the composition can be performed easily and easily in a severe environment such as when thickening reinforcement is applied to the lower surface of a concrete floor slab of a bridge. In addition, work efficiency can be improved and the construction period can be shortened.

Further, by increasing and reinforcing the surface of a concrete structure such as a bridge with the construction composition, construction can be performed in consideration of the scenery of the surface of the concrete structure.

Further, the fibrous material is more flexible than the concrete, and therefore the paint containing the same has a shock absorbing property and a property of following the deformation of the base material. The coating does not crack even if the concrete itself is deformed and cracks due to deformation.

The thickened reinforcing layer formed by the construction composition is excellent in waterproof performance,
Since it also has the effect of protecting pipes and the like, the life of the concrete structure can be extended, and the number of repairs can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a general bridge such as a highway to which a reinforcing structure for a concrete structure according to the present invention is applied.

FIG. 2 is an enlarged cross-sectional view of a part of a concrete slab of a bridge showing an embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a part of a concrete slab of a bridge showing an embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a part of a concrete slab of a bridge showing an embodiment of the present invention.

FIG. 5 is an enlarged sectional view of a part of a concrete slab of a bridge showing an embodiment of the present invention.

FIG. 6 is an enlarged sectional view of a part of a concrete slab of a bridge showing an embodiment of the present invention.

FIG. 7 is an enlarged sectional view of a part of a concrete slab of a bridge showing an embodiment of the present invention.

FIG. 8 is an enlarged sectional view of a part of a concrete floor slab of a bridge showing an embodiment of the present invention.

FIG. 9 is a sectional view showing an example in which a thickening reinforcing layer is provided on the upper surface of a concrete floor slab.

FIG. 10 is a construction drawing of a thickening reinforcement structure for a concrete structure according to the present invention.

FIG. 11 is a construction diagram of a thickening reinforcement structure for a concrete structure according to the present invention.

FIG. 12 is a cross-sectional view showing another example of a bridge capable of forming a thickening reinforcing layer.

[Explanation of symbols]

 2 Concrete floor slab 4 Thickening reinforcement layer a Coating of the composition for construction b Coating of the composition in which carbon fibers are mixed with the composition for construction c Coating of the composition in which metal fibers are mixed with the composition for construction d Carbon fibers Reinforcement fiber layer used e Reinforcement fiber layer using reinforcement fiber 13 Spray gun

Continuation of the front page (72) Inventor Goro Wakisaka 1-8-24 Nakazaki Nishi, Kita-ku, Osaka-shi, Osaka Prefecture Kabeichinai F-term (reference) 2D059 AA14 GG01 GG40 2E176 AA03 BB29 4G028 DA01 DB01 DB11 DB12

Claims (6)

[Claims] 1. A thickening reinforcing structure for a concrete structure having a thickening reinforcing layer formed on at least a part of a surface of the concrete structure, wherein the thickening reinforcing layer is made of cement, amorphous silica, aggregate, and synthetic material. A thickened reinforcing structure for a concrete structure, comprising at least one of a layer containing a resin, a layer containing cement, amorphous silica, an aggregate, a synthetic resin, and a fiber material. 2. A method according to claim 1, wherein said thickening reinforcing layer is formed of a component containing cement, amorphous silica, aggregate, and synthetic resin, and cement, amorphous silica, aggregate,
The thickening reinforcement structure for a concrete structure according to claim 1, wherein the structure is constituted by at least two layers including a layer formed of a component including a synthetic resin and a fiber material. 3. The reinforcing structure for a concrete structure according to claim 1, wherein the reinforcing layer has at least a three-layer structure further including a reinforcing fiber layer as an intermediate layer. 4. A method for constructing a thickening reinforcement structure for a concrete structure, wherein the thickening reinforcement layer is formed on at least a part of the surface of the concrete structure, wherein the thickening reinforcement layer comprises cement, amorphous silica, bone, At least one of a construction composition containing a material and a synthetic resin emulsion, cement, amorphous silica, aggregate, a synthetic resin emulsion, and a construction material containing a fiber material is constructed on the surface of a concrete structure. Construction method of thickening reinforcement structure of concrete structure. 5. The construction composition comprising a cement, an amorphous silica, an aggregate, and a synthetic resin emulsion, and a construction composition comprising a cement, an amorphous silica, an aggregate, a synthetic resin emulsion, and a fiber material. The method of claim 4, wherein the composition is alternately applied to form at least a two-layer structure. 6. The reinforcing reinforcement of a concrete structure according to claim 4, wherein a reinforcing fiber layer having at least a three-layer structure is formed by further applying a reinforcing fiber layer as an intermediate layer. Construction method of the structure.