JP4392415B2 - Reinforcement method for reinforced concrete buildings - Google Patents

Description

The present invention applies a simple construction to a reinforced concrete building such as a reinforced concrete (RC) building or a steel encased reinforced concrete (SRC) building, for example, before the revision of the Building Standard Law. on the reinforcement method of construction has been reinforced concrete-based building strength to raise Ru iron muscle concrete-based buildings equal to or greater than the reference strength of the current law of.

  The building is constructed with the reference strength specified in the Building Standards Act as the minimum reference value. On July 1, 2005, the Building Standards Law was enacted, and the “Act on Partial Revision of the Building Standards Law for Building Safety and Disaster Prevention Functions in Urban Areas” was enforced. A revision was made to raise the standard strength to improve seismic resistance and durability at the binding site. In buildings, reinforcement measures for improving the earthquake resistance and durability of properties built before the revision of the Building Standards Law are extremely important issues. In addition, the building is appropriately reinforced in order to restore the initial strength against deterioration with time.

In reinforced concrete buildings, tensile forces, compressive forces, bending moments, and shearing forces are applied to columns and beams due to earthquakes and the like, and these acting forces are countered by the reinforcing bars embedded in the concrete frame. In a reinforced concrete building, the reinforcing bar embedded in the concrete frame is composed of a main bar and a band bar (bark bar) that is combined with the main bar at a predetermined interval, and is caused by a bending moment. The main bars are the load-bearing elements exclusively for the force, and the strips are the load-bearing elements exclusively for the shearing force to maintain a predetermined seismic strength.

  In a reinforced concrete building, reinforcement work is generally performed by a reinforced concrete winding method or a reinforcing steel plate affixing method. However, the reinforcement work of such reinforced concrete buildings has problems such as an increase in weight and cross-sectional area, a longer construction period, and a higher cost. For this reason, in the reinforcement work of reinforced concrete buildings, the reinforcement fiber body is wrapped around the column to be reinforced, and the reinforcement fiber body is hardened with an adhesive to suppress an increase in weight and cross-sectional area. Reinforcement construction methods that aim at construction and cost reduction have been proposed (see, for example, Patent Document 1 to Patent Document 3).

JP-A-8-120948 JP 2000-54561 A JP 2000-314236 A JP 2004-44322 A

In the reinforcing method using the reinforcing fiber body and the adhesive described above, the base fiber of the reinforcing fiber body includes carbon fiber, glass fiber, metal fiber or aramid fiber, polyester fiber, etc., and the epoxy adhesive as the adhesive And various adhesives such as urethane adhesives, silicone adhesives, rubber adhesives, acrylic adhesives, and polyester adhesives. In such reinforcing construction method, it is integrated by a physical bonding by mechanical coupling and intermolecular attraction by an anchor effect by an adhesive between the base fiber of the reinforcing fiber material is cured by impregnating, the reinforcing fiber material The structural member is reinforced by the mechanical strength and bonded to the structural member by the adhesive force of the adhesive.

  However, such a reinforcing method is characterized in that carbon fibers, aramid fibers and the like used as reinforcing fiber bodies are expensive and have a large fiber diameter and a small adhesive impregnation efficiency. In such a reinforcement method, since the mechanical strength of the structural member is held by the reinforcing fiber body bonded to the structural member by the adhesive, the reinforcing strength is also determined by the characteristics of the reinforcing fiber body. In such a reinforcement method, it is difficult to obtain sufficient reinforcement strength as compared with the conventional method described above, and mechanical strength is exhibited only in the fiber arrangement direction.

  Further, in such a reinforcement method, when reinforcing the above-described reinforcing fiber body, for example, a carbon fiber body having a large mechanical strength, around the outer periphery of a column body having a rectangular, polygonal, or concavo-convex shape, carbon is used. It is difficult to wind the carbon fiber body while bending the carbon fiber body substantially at right angles along the ridgeline of the column body and sticking it because of the characteristics of the fiber that is hard and easy to break. In such a reinforcing method, there is a problem that a gap is generated between the column body and the carbon fiber body, and the column body cannot be reinforced with a predetermined strength. In such a reinforcement method, in order to wind the carbon fiber body in a state of being in close contact with the outer peripheral portion of the column body, for example, a setup process is performed in which a corner portion of the column body is scraped off into an arc shape. In such a reinforcement method, there has been a problem that repair costs increase due to the setup process and the construction period becomes longer.

  Furthermore, in the reinforcement method, when the above-mentioned adhesive, for example, an epoxy resin adhesive is used, the reinforcing fiber body and the column body are firmly bonded, but the epoxy resin has a high hardness in the cured state but also has a brittleness. Due to the above characteristics, there is a problem that the column body is peeled off due to large vertical and horizontal shaking due to an earthquake or the like and the column body cannot be sufficiently reinforced by the reinforcing fiber body. In other words, in the reinforcement method, the reinforced fiber body joined to the outer periphery of the column body is strong and has some elasticity against large vertical and horizontal shaking of the column body due to earthquakes, etc. It is necessary to have the following characteristics.

  On the other hand, in the above-mentioned conventional reinforcement methods, all are intended for reinforcement of pillars and the like, but can be employed as they are, for example, in seismic reinforcement walls formed integrally with the pillars or in places such as beams and slabs. Have difficulty. In Patent Document 2, a plurality of through-holes are formed in a wall portion connected to the column portion, and the portion is reinforced by fixing the column portion with an adhesive through a reinforcing fiber anchor in the through-hole. It is a construction method that makes possible. However, such a reinforcement method requires a very large-scale construction in which a large number of through holes are formed in the wall portion along each column portion, and the function of the seismic reinforcement wall is impaired.

Accordingly, the present invention can be applied to the reinforcement in all locations as target reinforced concrete-based buildings, provide Retrofit for rebars Concrete buildings you increase the strength of the reinforcing target portion by a simple construction It was proposed for the purpose of doing.

The reinforcing method for a reinforced concrete building according to the present invention that achieves the above-described object is to impregnate a cellulosic material with an epoxy resin adhesive in a reinforcing target portion of a reinforced concrete building whose proof strength has not reached the legal standard strength. As a result, chemical bonding is performed by intermolecular cross-linking between the OH group of the cellulose material and the epoxy group of the epoxy resin adhesive to form a cover that has a predetermined cross-sectional area and thickness and is integrated into a sheet. By doing so, it reinforces so that the said reinforcement | strengthening object location becomes a proof stress larger than a legal standard proof stress. Reinforcement methods for reinforced concrete buildings include the step of calculating the difference between the standard strength of the statutory standard specifications and the strength of the part to be reinforced as the difference in the amount of reinforcing bars, and the difference in the calculated amount of reinforcing bars in the shortage of the reinforcing bars. The minimum cross-sectional area dimension and the minimum thickness dimension of the reinforcing body are set through the step of converting as the cross-sectional area value and the step of correcting the converted insufficient cross-sectional area value by the rigidity ratio with the stirrup. In the reinforcing method for a reinforced concrete building, a reinforcing object having a cross-sectional area and a thickness larger than the minimum cross-sectional area dimension and the minimum thickness dimension is formed by covering a portion to be reinforced .

Reinforcement methods for reinforced concrete buildings are based on the difference in the amount of rebar reinforcement by applying a simple work to impregnate the cellulose material with epoxy resin adhesive at locations subject to reinforcement of the strength that is insufficient for the standard strength of the legal standard specifications. A sheet-like reinforcing body whose cross-sectional area and thickness having values larger than the minimum cross-sectional area size and minimum thickness dimension calculated based on the above-mentioned are controlled precisely is formed. Retrofit of RC-based buildings, more reinforcement, to reinforce and supplement the strength was not enough to the reinforcing target portion so as to be substantially equal or greater strength and reference Strength of legal standards specifications. Reinforcement method for reinforced concrete buildings is made by impregnating cellulose material with epoxy resin adhesive and chemically bonding by intermolecular cross-linking between OH group of cellulose material and epoxy group of epoxy resin adhesive. Forming a reinforced body . The reinforcement method for reinforced concrete buildings is made of a cellulose material that is cheaper and softer, lighter and easier to handle than the reinforced fibers such as carbon fiber and aramid fiber listed in the conventional method. Further, it is possible to provide a reinforcing body in a state of being in close contact with the entire area to be reinforced, which has a rectangular shape, a polygonal shape, or an uneven shape. The reinforcement method for reinforced concrete buildings is an epoxy resin in which the cellulosic material has more OH groups than the reinforcing fibers of the conventional method, and these OH groups are ring-opened by the action of a curing agent made of a bifunctional compound. An intermolecular cross-linking structure in which the epoxy resin is cured by polymerizing with the group is efficiently generated even between the epoxy resin and the cellulose material to form a chemically bonded reinforcement .

  Reinforcement method for reinforced concrete buildings is a hardened but hard brittle epoxy resin adhesive that is complemented by chemically bonded cellulosic material properties, such as reinforcing fibers mentioned in the conventional method The portion to be reinforced is reinforced by a reinforcing body that is stronger and more elastic than a reinforcing sheet body impregnated with epoxy resin. Reinforcement methods for reinforced concrete buildings are maintained even if the location to be reinforced is greatly swayed vertically or horizontally due to an earthquake, etc. Reinforce the part securely and firmly.

The reinforcing method for a reinforced concrete building according to the present invention is the minimum breakage calculated based on the difference in the amount of reinforced reinforcing bars covering the reinforcement target location where the proof strength has not reached the legal standard strength. A reinforcing body having an optimum cross-sectional area and thickness larger than the area dimension and the minimum thickness dimension is formed. The reinforcing method for a reinforced concrete building according to the present invention is such that the reinforcing body is chemically bonded by intermolecular crosslinking between the OH group of the cellulose material and the epoxy group of the epoxy resin adhesive by impregnating the cellulose material with the epoxy resin adhesive. It is tough and elastic by complementing the properties of the epoxy resin adhesive that has a high hardness in the cured state but is brittle with the properties of the chemically bonded cellulose material. According to the present invention, a reinforcing body having an optimal cross-sectional area and thickness larger than the minimum cross-sectional area dimension and the minimum thickness dimension calculated on the basis of the difference in the amount of reinforcing steel bars is formed by covering the portion to be reinforced. . According to the reinforcement method for a reinforced concrete building according to the present invention, by forming a reinforcing body having the above-described characteristics by simple construction with respect to the reinforcement target location, the reinforcement target location is defined as the standard proof stress of the legal standard specification. Reinforce to the same or higher strength. According to the reinforcing method for a reinforced concrete building according to the present invention, the reinforcing body is not peeled off from the portion to be reinforced, and the proof strength of the reinforced concrete building whose proof strength has not reached the statutory standard proof strength is low and short. It is possible to perform reinforcement to improve the earthquake resistance and durability by this work.

  Hereinafter, a reinforcing body 1 that reinforces a reinforced concrete building (RC building) shown as an embodiment of the present invention and a reinforcing method using the reinforcing body 1 will be described in detail with reference to the drawings. It should be noted that the present invention is not only applied to reinforcement of reinforced concrete buildings, but of course similarly applied to steel reinforced concrete buildings (SRC buildings) in which reinforcing bars are arranged around steel frames. is there. The present invention is applicable not only to reinforced concrete buildings but also to various reinforced concrete buildings such as viaduct legs.

  As shown in FIG. 1, the reinforcing body 1 is constituted by a long sheet body having a predetermined thickness h (mm) in which, for example, a cellulose sheet body 2 is impregnated with an epoxy resin adhesive 3 composed of a main agent and a curing agent. The As shown in FIG. 2, the reinforcing body 1 is wound around an existing reinforced concrete structure to be reinforced, for example, an outer peripheral portion of a column body 4 over a range of a predetermined length L (mm). Raise the seismic strength of the body 4 beyond the standard strength specified in the current Building Standard Law.

  Since the reinforcing body 1 hardens the epoxy resin adhesive 3 to harden the cellulose sheet body 2 and joins it to the outer peripheral surface of the column body 4, the characteristics of the cellulose sheet body 2 and the epoxy resin adhesive 3 are exhibited. It exhibits great mechanical resistance against tensile and compressive forces required as a reinforcing material and has elastic properties. Therefore, the reinforcing body 1 maintains a state of being in close contact with the outer peripheral portion without peeling from the column body 4 that swings up and down and left and right due to an earthquake, and exerts a reinforcing action. For the reinforcing body 1, a material formed on a sheet body using, for example, degreased cotton, baker cotton, cellulose fiber, or the like as a material of the cellulose sheet body 2 is used. The cellulose sheet body 2 is less expensive than carbon fibers, aramid fibers, and the like proposed in the conventional construction method, and has the characteristics that small diameter fibers are intertwined in a complicated manner and have high flexibility and water retention.

  The cellulose sheet body 2 is a natural material, and no toxic gas is generated even in the event of a fire. Incidentally, Panya cotton is a fiber cotton obtained from evergreen Takagi of Panyaceae, and is a safe material used as a filler for cushions, futons or pillows, for example. Cellulose fiber is a material made by pulverizing corrugated cardboard made of natural wood material as a main material, and is used as a heat insulating material by laying it on the back of a ceiling as a building material.

Cellulose is represented by a molecular formula of [C ₆ H ₇ O ₂ (OH) ₃ ] n, and has more OH groups than the above-described carbon fiber and the like, so that the uncured epoxy resin adhesive 3 It has the property of being actively added to oxygen atoms and cross-linking between molecules. The cellulose sheet body 2 has a higher degree of OH group exposure by using the above-described degreased cotton or the like, and is more reactive with the epoxy resin adhesive 3.

  Epoxy resin adhesive 3 is a two-part epoxy resin adhesive that is easy to handle and hardens by mixing a curing agent with a commonly used main agent, or a one-part room temperature curing type epoxy resin adhesive that does not require mixing. An agent is used. As is well known, the two-component mixed epoxy resin adhesive is mainly composed of a thermosetting resin produced by polymerization of bisphenol A and epichlorohydrin and having two or more epoxy groups in one molecule. For example, a curing agent composed of an amine such as diethylenetriamine, or a bifunctional compound such as an organic acid or an acid anhydride is used. The two-component mixed epoxy resin adhesive is cured into a stable three-dimensional structure by causing a ring opening of an epoxy group and a reaction with an OH group by mixing a curing agent with a main agent, resulting in a cross-linking bond. The two-component mixed epoxy resin adhesive is characterized by high hardness, small shrinkage upon curing and strong adhesive strength, but high brittleness. In the two-component mixed epoxy resin adhesive, a low-temperature reactive curing accelerator such as a tertiary amine is also added to the curing agent.

  As the epoxy resin adhesive 3, for example, Everbond EP-400 manufactured by Nippon Seika Co., Ltd. is used. Everbond EP-400 is composed of a main component comprising phenol novolac type epoxy resin, n-butyl-2,3-epoxypropyl ether and reactive diluent, modified aliphatic polyamine, aliphatic polyamine and meta-xylylenediamine. And a curing agent containing, as appropriate, polyamidoamine, phenol, and cresol.

  As the one-component room temperature curing type epoxy resin adhesive, for example, an epoxy resin type one-component room temperature curing adhesive “Uniepo repair primer” manufactured by Konishi Co., Ltd. is used. One-pack room-temperature curing epoxy resin adhesive is a mixture of liquid bisphenol A type epoxy resin and curing agent ketimine mixed with calcium oxide, silica, and zinc oxide. It reacts with OH groups when exposed to the atmosphere. Has the property of curing.

In the reinforcing method, as shown in FIG. 2, the epoxy resin adhesive 3 is applied to the outer peripheral surface of the column 4 to be reinforced over a predetermined length region L by an appropriate adhesive spraying means 5 such as a spray gun. Thus, the base adhesive layer 6 is formed. In the reinforcing method, the above-described cellulose sheet body 2 formed to have a predetermined thickness and width when the epoxy resin adhesive 3 of the base adhesive layer 6 is uncured is wound around the outer peripheral surface of the column 4. In the reinforcing method, the epoxy resin adhesive 3 is further sprayed on the wound cellulose sheet body 2 by the adhesive spraying means 5 to form the reinforcing body 1, and the column body 4 is reinforced by the reinforcing body 1.

In strengthening method, an epoxy resin adhesive 3 of the underlying adhesive layer 6, and hardened by impregnating the inner surface of the cellulosic sheet material 2 therein, firmly the cellulosic sheet material 2 on the outer peripheral surface of the columnar body 4 Join. In the reinforcing method, the epoxy resin adhesive 3 sprayed in the subsequent step is impregnated into the inside from the outer surface side of the cellulose sheet body 2 and chemically formed by the intermolecular cross-linking structure together with the epoxy resin adhesive 3 of the base adhesive layer 6. binding is performed to form the reinforcing member 1. In the reinforcing method, the properties of the epoxy resin adhesive 3 having a high hardness in a cured state but having brittleness are complemented by the properties of the chemically bonded cellulose sheet body 2, and a large mechanical strength against tensile force and compressive force. The column body 4 is reinforced by the reinforcing body 1 having resistance. Moreover, in the reinforcement construction method, since the reinforcing body 1 retains the appropriate elasticity of the cellulose sheet body 2, the acting force due to the large shaking caused by the earthquake is absorbed and the separation or breakage from the column body 4 occurs. It is reduced and the pillar body 4 is securely and firmly held to improve the earthquake resistance and durability.

  In the reinforcing method, for example, the reinforcing body 1 may be configured by winding the cellulose sheet body 2 impregnated with the epoxy resin adhesive 3 in advance around the column body 4. In the reinforcing method, for example, the step of forming the base adhesive layer 6 may be omitted by spraying the epoxy resin adhesive 3 in a state where the cellulose sheet body 2 is wound around the column body 4 and temporarily held. . Further, the reinforcing method is not limited to the step of spraying the epoxy resin adhesive 3, and for example, using a package that stores the cellulose sheet body 2 and the epoxy resin adhesive 3 in a state of being separated by the separate portion, Alternatively, the reinforcing body 1 may be configured by removing and removing the epoxy resin adhesive 3 from the cellulose sheet body 2 and impregnating it. In the reinforcing method, the epoxy resin adhesive 3 may be applied to the column body 4 and the cellulose sheet body 2 by an appropriate method as well as the spraying method.

In the reinforcement method, as described above, the reinforcing body 1 having a predetermined thickness h is formed over a predetermined length L with respect to the column body 4 that does not have the standard yield strength defined in the current building standard law. it allows pulling the seismic intensity equivalent columnar body 4 so as to be substantially equal to or greater than a reference strength. In reinforced concrete buildings, as mentioned above, the reinforcing bar is an effective measure against the shear force acting on the column 4 because the reinforcing bar is an important strength element rather than the main reinforcing bar. It becomes. In the reinforcement method, as will be described later, the insufficient strength of the column body 4 with respect to the standard strength specified in the current Building Standard Law is calculated by the difference in the amount of reinforcing bars and converted into the cross-sectional area value of the reinforcing bars. In the reinforcing method, the reinforcing body 1 described above is formed so that the cross-sectional area and thickness are calculated from the cross-sectional area value based on the rigidity ratio with the reinforcing bar, and the cross-sectional area and thickness are larger.

  As shown in FIG. 3, the column body 4A having the standard proof strength defined in the current Building Standards Law has a predetermined pitch P1 (mm) around the outer periphery of a large number of main bars 7A erected from a footing or the like. Reinforcing bars are arranged by surrounding the reinforcing bars 8A, and the main reinforcing bars 7A and the reinforcing bars 8A are embedded to form a concrete frame 9A. The column 4A of the current law specification is configured by applying a surface treatment such as painting or applying a decorative body to the surface of the concrete housing 9A. In the column 4A of the current method specification, deformed reinforcing bars (with ribs and nodes) having an outer diameter of 13 mm or more are used for the main reinforcing bars 7A, and the main reinforcing bars 7A are embedded with a reinforcing bar ratio of 0.8% or more of the concrete cross section.

In the column 4A of the current method specification, a reinforcing bar with a diameter of 10 mm or more is used for the hoop 8A, and the reinforcing bar 7A is arranged with a hoop ratio of 0.2% or more at 100 mm or less with respect to the main bar 7A. In the band 8A, the cross-sectional area is A1 (mm ² ), the allowable tensile stress of the reinforcing bar is T1 (N / mm ² ), the Young's modulus is Et (N / mm ² ), and the column length L (mm) is within the range. The main bars 7A are arranged at a pitch P1 (mm).

As described above, the reinforcing method is provided by integrating the reinforcing body 1 on the outer peripheral portion as shown in FIG. 4 with respect to the column body 4B of the reinforced concrete building constructed before the revision of the Building Standards Law. Reinforce the proof strength equal to or better than the revised column 4A. In the conventional specification column body 4B, ordinary round steel having an outer diameter of 9 mm or more is generally used for the main reinforcing bar 7B and the reinforcing bar 8B, and the reinforcing bar is constituted by arranging the reinforcing bar 8B at a large pitch on the outer periphery of the main reinforcing bar 7B. The concrete reinforcement 9B is formed by embedding the main reinforcement 7B and the band reinforcement 8B. In the column 4B of the previous specification, the band 8B has the same Young's modulus Et (N / mm ² ) as the band 8A of the current method specification, but the allowable tensile stress is T2 (N / mm ² ) and the cross-sectional area is A2 (mm ² ) is arranged at a pitch P2 (mm) with respect to the main reinforcement 7B in the range of the column length L (mm).

Reinforcement 1, the outer peripheral portion of the cylindrical body 4B of prior specifications mentioned above, as shown in FIG. 4, by being formed over a predetermined thickness h and a predetermined length L, a for this pillar 4B The shortage proof strength with the standard proof strength of the column 4A of the current law specification described above is complemented. The reinforcing body 1 has a tensile strength of Fe (N / mm ² ), an allowable tensile stress of Te (N / mm ² ), a Young's modulus of Ee (N / mm ² ), a thickness of h (mm), The area is Ae (mm ² ) and the column length L (mm) is formed.

  In the reinforcement construction method, the specification of the reinforcing body 1 is determined by the following calculation steps and formed on the outer peripheral portion of the column body 4B of the previous specification.

(Calculation step 1)
The insufficient proof strength F of the column 4B of the previous specification relative to the column 4A of the current law specification is calculated by the difference in the amount of reinforcing bars. Insufficient yield strength F is
Reinforcing bar quantity K1: T1 × L / P1 × 2A1
Reinforcing bar amount K2 of conventional specification column 4B: T2 × L / P2 × 2A2
Insufficient yield strength F = K1-K2 = (T1 * L / P1 * 2A1)-(T2 * L / P2 * 2A2)
Can be obtained.

(Calculation step 2)
The insufficient proof stress F is converted into the cross-sectional area A3 of the reinforcing bar. The cross-sectional area A3 of the reinforcing bar is
A3 = F / T2
Can be obtained.

(Calculation step 3)
Based on the converted rebar cross-sectional area A3, the required cross-sectional area Ae and the required thickness h of the reinforcing body 1 are obtained. Since the reinforcing body 1 is formed of the cellulose sheet body 2 and the epoxy resin adhesive 3 as described above, the rigidity of the reinforcing bar is different, and correction is performed by the ratio of the Young's modulus Ee and the Young's modulus Et of the reinforcing bar. The required cross-sectional area Ae is obtained. The required cross-sectional area Ae is
Ae = A3 × Et / Ee
And the required thickness h is
h = Ae / 2L
Can be obtained.

(Calculation step 4)
It is verified whether the column body 4B of the previous specification in which the reinforcing body 1 having the cross-sectional area Ae and the thickness h obtained in the above steps 1 to 3 is raised to the proof stress of the column body 4A of the current method specification. In the verification, the tensile strength Fe of the reinforcing body 1 is obtained by the following formula from the allowable tensile stress Te and the cross-sectional area Ae,
Fe = Te × Ae
The tensile strength Fe is equal to or greater than the insufficient strength F. Fe ≧ F
Confirmation is performed by satisfying the following conditions. In the reinforcing method, appropriate reinforcement is performed on the column body 4B of the previous specification by using the cross-sectional area Ae calculated based on the difference in the amount of reinforcing bars and the reinforcing body 1 of the thickness h specification.

  By the way, the reinforced concrete building is different from the reinforcing bar specification A after 1981 based on the provisions of the current Building Standard Law, and the reinforcing bar specifications B and 1971 are based on the provisions of the Building Standard Law of 1971 to 1980, which are different standards. It is built according to the reinforcing bar specification C based on the provisions of the Building Standard Law before the year.

  The specifications of the cross-sectional area Ae and the thickness h are determined based on the calculation steps described above for the reinforced concrete buildings constructed according to the reinforcing bar specifications B and C shown in Table 1, and the yield strength is equal to or higher than the reinforcing bar specification A. A specific example of the reinforcing method for forming the reinforcing body 1 will be described below. In addition, the tensile strength of each reinforcing bar shown in the table is the minimum value of the allowable proof strength described in the reinforced concrete structure calculation standard and the same explanation.

The reinforcing body 1 has different Young's modulus and tensile strength depending on the specifications of the cellulose sheet body 2 and the epoxy resin adhesive 3 to be used. For example, a specimen is manufactured and a material tensile test is performed to obtain these. And Reinforcement 1 has a Young's coefficient of ^{1.6 × 10 3 (N / mm} 2), the mean maximum tensile stress was 42N / mm ^2. Since the reinforcing body 1 uses the allowable tensile stress value for the reinforcing bar in the calculation step as described above, 2/3 of the maximum tensile stress value and 28 N / mm ² are used as the converted values as the allowable tensile stress value. The Young's modulus of the reinforcing bar is 2.05 × 10 ⁵ (N / mm ² ), which is about 128 times that of the reinforcing body 1.

A. The total cross-sectional area of the reinforcing bars 8A arranged at intervals of 1000 mm in a reinforced concrete building (column 4A) that uses the reinforcing bar specification A based on the provisions of the current Building Standards Act after 1981 as a reference (total reinforcing bar) Amount) and tensile strength, from Table 1. Total cross-sectional area: 127 (mm ² ) × 2 × 1000 (mm) / 100 (mm) = 2540 (mm ² )
Tensile strength: 295 (N / mm ² ) × 2540 (mm ² ) = 749300 (N)
It becomes.

B. The total cross-sectional area (total amount of reinforcing bars) of the reinforcing bars 8B arranged at intervals of 1000 mm in the reinforced concrete building (column 4B) constructed according to the reinforcing bar specification B based on the provisions of the Building Standards Act of 1971 to 1980 And the tensile strength from Table 1 Total cross-sectional area: 64 (mm ² ) × 2 × 1000 (mm) / 100 (mm) = 1280 (mm ² )
Tensile strength: 235 (N / mm ² ) × 1280 (mm ² ) = 300 800 (N)
It becomes.

The reinforcement for the column 4B is as follows:
Insufficient yield strength due to insufficient amount of reinforcing bars: FB = 749300 (N) -300800 (N) = 448500 (N)
Cross-sectional area of the short band 8B: A3B = 448500 (N) ÷ 235 (N / mm ² ) = 1909 (mm ² )
Since the insufficient cross-sectional area A3B of the band 8B is reinforced by the reinforcing body 1C, the rigidity is corrected using the Young's modulus ratio (128) and the required film thickness hB is obtained. The required film thickness hB = 1909 (mm ² ) × 128 ÷ 2000 (mm) = 122 (mm)
It becomes.

As described above, if the reinforcement body 1B adopts 28 (N / mm ² ) as the allowable tensile strength value, it has a thickness hB of 122 mm. Therefore, the tensile strength FeB is equal to the tensile strength FeB = 2000 (mm) × 122 ( ^{mm) × 28 (N / mm} 2) = 6832000 (N)
Thus, it exceeds 448500 (N) of the above-mentioned insufficient yield strength FB.

  Therefore, the reinforcement of the reinforced concrete building constructed by adopting the reinforcing bar specification B is to form the reinforcing body 1B having a thickness hB of 122 mm with respect to the column body 4B, thereby making the column body 4B the current building standard law. It is possible to raise the yield strength to the same level as that of a reinforced concrete building constructed according to the reinforcing steel specification A based on the regulations.

C. The total cross-sectional area (total amount of reinforcing bars) and tension of the reinforcing bars 8C arranged at intervals of 1000 mm in the reinforced concrete building (column 4C) constructed according to the reinforcing bar specification C based on the provisions of the Building Standard Law before 1970 strength, the total cross-sectional area from Table ^{1: 64 (mm 2) ×} 2 × 1000 (mm) / 200 (mm) = 640 (mm 2)
Tensile strength: 235 (N / mm ² ) × 640 (mm ² ) = 150400 (N)
It becomes.

The reinforcement for the column 4C is as follows:
Insufficient yield strength due to insufficient amount of reinforcing bars: FC = 749300 (N)-150400 (N) = 598900 (N)
Cross-sectional area of the short band 8C: A3C = 598900 (N) ÷ 235 (N / mm ² ) = 2549 (mm ² )
The lack of cross-sectional area A3C of hoop-8C be reinforced by the reinforcing member 1C, Young's modulus ratio (128) when determining the required thickness hC I row stiffness corrected using the required thickness hC = 2549 ^(mm 2) × 128 ÷ 2000 (mm) = 163 (mm)
It becomes.

The reinforcing body 1C has a thickness hC of 163 mm when an allowable tensile strength value of 28 (N / mm ² ) is adopted as described above. Therefore, the tensile strength FeC is equal to the tensile strength FeC = 2000 (mm) × 163 ( mm) × 28 (N / mm ² ) = 9128000 (N)
Thus, it exceeds the above-mentioned insufficient proof strength FC of 598900 (N).

  Therefore, the reinforcement of the reinforced concrete structure constructed by adopting the reinforcing bar specification C is performed by forming the reinforcing body 1C having the thickness hC of 163 mm with respect to the column body 4C, thereby making the column body 4C the current building standard law. It is possible to raise the yield strength to the same level as that of a reinforced concrete building constructed according to the reinforcing steel specification A based on the regulations.

The first embodiment described above showed an example of application to an independent cylindrical body 4, it is not intended the invention be limited to such applications. The reinforcement method for a reinforced concrete building shown in FIG. 5 as the second embodiment is applied to a reinforced concrete building in which a seismic wall 12 is integrated with a column 11 to form a so-called seismic wall structure 10. It is. The seismic wall structure 10 is formed by continuously arranging a bar part and a wall part to form a reinforcing bar core, and embedding the reinforcing bar core with a concrete frame 13. In the seismic wall structure 10, a reinforcing bar is formed by combining the main bar 7 and the strip 8 in the same manner as the column 4 described above in the part of the column 11, and the vertical bars 18 and the horizontal bars 19 are provided in the part of the earthquake wall 12. For example, reinforcing bars are constructed by double bar arrangement.

In the reinforcing method, since the earthquake- resistant wall 12 is integrated with the earthquake- resistant wall structure 10, the reinforcement is obtained by winding the cellulose sheet 2 around the outer periphery of the column 11 like the independent column 4 described above. The body 1 cannot be formed. Therefore, in the reinforcing method, the sheet-like reinforcing body 14A along the height direction straddling the columnar body 11 and the reinforcing body forming portions 12A and 12B of the earthquake-resistant wall 12 on both sides of the earthquake-resistant wall structure 10 respectively. 14B is formed. In the reinforcing method, the sheet-like reinforcing bodies 14A and 14B are formed by spraying, for example, a powdery cellulose material 15 onto the pillar body 11 and the earthquake-resistant wall 12 by the cellulose spraying means 16 .

The spraying reinforcement construction method is not shown in the state in which dirt and the like are removed from the surfaces of the reinforcement body forming portions 12A and 12B of the column body 11 and the earthquake-resistant wall 12 in the same manner as the above-described reinforcement construction method. sprayed on the surface of its forming the underlying adhesive layer 6 over the epoxy resin adhesive 3 in column body 11 and the shear wall 12 by. The spray-reinforcing method is an uncured state of the epoxy resin adhesive 3 of the base adhesive layer 6, for example, an eco-life cellulose fiber (trade name: Hightherm) or a natural cellulose oil adsorbent sold by Mitsubishi Corporation (trade name) : Cellulose material 15 such as floor gator & cell soap) is sprayed by an appropriate cellulose spraying means 16 to form a cellulose layer.

In the spraying reinforcement method, the epoxy resin adhesive 3 of the base adhesive layer 6 is impregnated into the cellulose layer and cured to form a reinforcing body 14, and the reinforcing body 14 is used to reinforce the column body 11 and the earthquake resistant wall 12. body forming portion 12A, joined to the strong solid across 12B. In spraying strengthening method, sufficiently impregnated with epoxy resin adhesive 3 to the cellulosic material 15 by spraying epoxy resin adhesive 3 by means 5 spraying adhesive from the surface side of the reinforcing member 14, an epoxy resin adhesive 3 and cellulose A reinforcing body 14 in which the material 15 is chemically bonded to each other by an intermolecular cross-linked structure is formed.

In the spray reinforcement method, when the reinforcing body 14 is insufficient for the above-described thickness and cross-sectional area, the spraying of the cellulose material 15 and the epoxy resin adhesive 3 is repeated to obtain a predetermined thickness. In the spray reinforcement method, the reinforcing body 14 is formed in a state of being in close contact with the entire region without exhibiting a floating state even at the ridge line portion of the column body 11 or the connected portion of the column body 11 and the earthquake-resistant wall 12. Also in spraying strengthening method has a large hardness cured state supplemented by the properties of the cellulose material 15 chemically bonded to properties of epoxy resin adhesive 3 which is brittleness, large mechanical against the tensile force and compressive force The seismic wall structure 10 is reinforced by forming a reinforcing body 14 having resistance across the column 11 and the seismic wall 12.

Also in spraying strengthening method, the reinforcing member 14, since the holding also suitable elasticity of the cellulose material 15, occurrence of peeling or breakage from pillar 11 and the shear wall 12 absorbs the acting force due to a large shaking due to an earthquake Is reduced and the seismic wall structure 10 is securely and firmly held to improve seismic resistance and durability. In the spray reinforcement method, it is not necessary to provide a through-hole through which the cellulose sheet body penetrates at a continuous portion between the column body 11 and the earthquake-resistant wall 12. Therefore, in the blowing reinforcement method, it is possible to form the reinforcing body 14 by simple construction without reducing the seismic strength of the seismic wall structure 10.

By the way, since the reinforcing body 14 is formed so as to straddle the pillar body 11 and the earthquake-resistant wall 12 as described above, a part of the reinforcing body 14 is cut off when attention is paid to the reinforcement of the pillar body 11 alone. Compared with the body 1, the proof stress is reduced. The reinforcing body 14 is formed by extending the reinforcing body forming portions 12A and 12B on both sides of the seismic wall 12 sandwiching the column body 11, thereby reinforcing the seismic wall 12 at the forming portion. The column body 11 integrated with is reinforced in the same manner as the reinforcing body 1. Since the reinforcing body 14 performs predetermined reinforcement by setting it to have an optimal cross-sectional area and thickness, the entire body can be made thin by the width of the reinforcing body forming portions 12A and 12B of the earthquake resistant wall 12. is there.

In addition, about the reinforcement construction method of the earthquake-resistant wall structure 10, it is not limited to the spray reinforcement construction method mentioned above, For example, the cellulose material 15 which mixed the epoxy resin adhesive 3 beforehand is sprayed over the pillar 11 and the earthquake-resistant wall 12 and sprayed. The reinforcing body 14 may be formed, and the strength can be improved without impairing the seismic strength of the seismic wall 12. Further, the reinforcing method of the earthquake resistant wall structure 10 is not limited to the method of spraying the cellulose material 15. For example, the cellulose sheet body 2 impregnated with the epoxy resin adhesive 3 in advance is straddled between the column body 11 and the earthquake resistant wall 12. The reinforcing body 14 may be formed by pasting. The cellulose sheet body 2 is flexible in the uncured state of the epoxy resin adhesive 3 and can be bonded to the column body 11 and the earthquake-resistant wall 12 in close contact.

In the reinforcing method of the seismic wall structure 10, the reinforcing body 14 straddling the seismic walls 12 on both sides is formed along the column body 11 as described above. However, the method is not limited to this method. is there. In the reinforcing method of the earthquake-resistant wall structure 10, since the earthquake-resistant wall structure 10 has a structure in which the column body 11 and the earthquake-resistant wall 12 are integrated to obtain a predetermined earthquake-resistant strength, the earthquake-resistant wall 12 is entirely covered. Reinforcement is also required. Therefore, in the reinforcing method of the earthquake-resistant wall structure 10, the reinforcement body 14 that covers the entire earthquake-resistant wall 12 together with the column body 11 may be formed.

  The present invention is applied not only to the reinforcement of the column bodies 4 and 11 as described above, but also to the reinforcement of the beam 20 and the slab 21 shown as the third embodiment in FIG. In a reinforced concrete building, a ramen structure in which the column 1 and the beam 20 are integrated is often adopted, and the reinforcement of the beam 20 is extremely important in addition to the reinforcement of the column 1. In the beam 20 having such a ramen structure, a plurality of main bars 22 connected perpendicularly to the main bar 7 of the column 1 are arranged with a bar 23 with a predetermined pitch to form a reinforcing bar. Embedded in the housing 24.

Since the slab 21 is also integrated with the beam 20 in the same manner as the above-described seismic wall structure 10, the reinforcing body 25 is made into the beam 20 and the slab 21 by a spraying method or a bonding method. Form straddle. Also in the reinforcing method of the beam 20, the stirrup 23 is a more important strength element than the main rebar 22 against the shearing force applied by an earthquake or the like. Therefore, in the reinforcing method of the beam 20, as in the case of the reinforcing method of the column 1 described above, the insufficient strength of the beam 20 with respect to the standard strength specified in the current building standard method is calculated based on the difference in the amount of reinforcing bars. The cross-sectional area value is converted into a cross-sectional area value, and the cross-sectional area and thickness are calculated from the cross-sectional area value based on the rigidity ratio with the reinforcing bar. The beam 20 and the slab 21 have a cross-sectional area and thickness larger than the calculated cross-sectional area and thickness. that form a reinforcing member 2 5 spanning and.

In the reinforcing method of the beam 20, but so as to form a reinforcing member 2 5 across the slab 21 along the beam 20 and its side regions, as described above, it is not limited to such a method as a matter of course. In the reinforcing method of the beam 20, the reinforcing body 25 that covers the entire slab 21 together with the beam 20 may be formed.

In the present invention, as described above, the cellulose sheet body 2 (cellulose material 15) is impregnated with the epoxy resin adhesive 3, and the characteristics of the epoxy resin adhesive 3 having high hardness but brittleness in the cured state are chemically treated. the structural moiety of the reinforcement 1 (reinforcement 14,2 5) formed by cylindrical body 4 and the beam 20 or the like reinforced concrete based structures of a given cross-sectional area and thickness which is complemented by the characteristics of the cellulosic sheet 2 bonded to Reinforce. Therefore, the present invention can reinforce the column 30 having a complicated cross-sectional shape as shown in FIG. 7, for example, by forming a strong and elastic elastic body 31 on the outer periphery thereof. And

  The column body 30 has a large number of irregularities on the outer peripheral portion, and cannot be reinforced by a conventional reinforced concrete winding method or a reinforcing steel plate affixing method. Further, the column body 30 also has a sufficient reinforcement because, for example, reinforcement using a carbon fiber body is difficult because it is hard and easy to bend, and the carbon fiber body is difficult to be wound while being bent at a right angle to the outer peripheral portion at a concavo-convex part. Can not do.

  According to the reinforcing method according to the present invention, since the cellulose sheet body 2 has flexibility, the cellulose sheet body 2 can be brought into close contact with the uneven portion formed on the outer peripheral portion of the column body 30, and the outer periphery of the column body 30 can be adhered. It is possible to increase the strength by forming the reinforcing body 31 over the entire area. Further, even if the reinforcing body 31 is a portion having a small joint area with the column body 30, the reinforcement body 31 is strong and elastic, so that it is elastically deformed following each part of the column body 30 that is deformed in the event of an earthquake or the like and acts to some extent. The reinforcing property is retained without absorbing the force and peeling from the column 30.

  As described above, according to the present invention, a reinforcing body having toughness and elasticity is formed by applying the same process to any part such as a column, a beam, a wall, or a slab for a reinforced concrete building. Is possible. Therefore, according to the present invention, even for a reinforced concrete building that was built before the revision of the Building Standards Act and does not reach the seismic strength of the current standard, the reinforcement having a predetermined cross-sectional area and thickness in each part by simple work It is possible to raise the earthquake resistance by forming the body.

It is a principal part front view of a reinforcement body. It is explanatory drawing of the column reinforcement method shown as 1st Embodiment. It is explanatory drawing of the reinforcing bar specification based on the present building standard law. It is explanatory drawing of the conventional reinforcing bar specification reinforced with the elastic body. It is explanatory drawing of the reinforcement construction method of the earthquake-resistant wall structure shown as 2nd Embodiment. It is explanatory drawing of the reinforcement construction method of a beam and a slab shown as 3rd Embodiment. It is explanatory drawing of the reinforcement method of a polygonal column shown as 4th Embodiment.

DESCRIPTION OF SYMBOLS 1 Reinforcement body, 2 Cellulose sheet body, 3 Epoxy resin adhesive, 4 Column body, 5 Adhesive spraying means, 6 Base adhesive layer, 7 Main reinforcement, 8 strip reinforcement, 9 Concrete frame, 10 Earthquake resistant wall structure, 11 pillar Body, 12 Seismic wall, 13 Concrete frame, 14 Reinforcement body, 15 Cellulose material , 16 Cellulose spraying means, 20 Beam, 21 Slab, 22 Main reinforcement, 23 Stirrup, 24 Reinforcement body, 30 Column body, 31 Reinforcement body

Claims (1)

The OH group of the cellulose material and the epoxy group molecule of the epoxy resin adhesive by impregnating the cellulosic material with an epoxy resin adhesive for the reinforcement target location of the reinforced concrete building whose proof strength has not reached the legal standard yield strength By carrying out chemical bonding by inter-crosslinking to form a covering that has a predetermined cross-sectional area and thickness and is integrated into a sheet, the portion to be reinforced has a greater yield strength than the legal standard yield strength. is the reinforcement method of reinforced concrete-based buildings to reinforce in such a way that,
Calculating the difference between the standard proof strength of the legal standard specification and the proof strength of the portion to be reinforced as a difference in the amount of reinforcing bar,
A step of converting the calculated difference in the amount of the rebar reinforcing bar as an insufficient cross-sectional area value of the rebar,
For the converted insufficient cross-sectional area value, through the step of correcting by the stiffness ratio with the stirrup, set the minimum cross-sectional area dimension and minimum thickness dimension of the reinforcing body,
A reinforcing method for a reinforced concrete building, characterized in that the reinforcing body having a cross-sectional area and a thickness larger than the minimum cross-sectional area dimension and the minimum thickness dimension is formed by covering the portion to be reinforced.

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