JP2007255130A - Reinforcing body and reinforcing method for reinforced concrete-based building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable application to reinforcement in any place of an intended reinforced concrete-based building, and to increase the strength of a place-to-be-reinforced by simple construction. <P>SOLUTION: A cellulose material 2, which is provided in the place-to-be-reinforced of the reinforced concrete-based building so as to make the strength of the place-to-be-reinforced higher than reference strength, is impregnated with an epoxy resin adhesive 3. This makes a reinforcing body 1 cured, and imparts a predetermined rigidity value to the reinforcing body 1. A cross-sectional area and thickness are greater in value than a cross-sectional area and thickness, which are computed on the basis of the rigidity ratio of the reinforcing body 1 to the reinforcement from a value of the cross-sectional area obtained through the following step: the insufficient strength of the place-to-be-reinforced with respect to the reference strength is computed from a difference between areas of reinforcement, and converted to the value of the cross-sectional area of the reinforcement. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention applies a simple construction to a reinforced concrete structure such as a reinforced concrete (RC) structure or a steel encased reinforced concrete (SRC) structure, for example, before the revision of the Building Standard Law. The present invention relates to a reinforcing body for a reinforced concrete building and a reinforcement method for a reinforced concrete building that raises the proof strength of the reinforced concrete building that has been constructed to exceed the standard proof strength of the current method.

  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 bars embedded in the concrete frame are composed of band bars (separated bars) arranged at a predetermined interval with respect to the main bars, and are exclusively used for the tensile force generated by the bending moment. The main reinforcement acts as a strength element, and the band reinforcement acts solely as a strength element against 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 a reinforcement method, the mechanical strength of the reinforcing fiber body is integrated by mechanical bonding by an anchor action and physical bonding by intermolecular attractive force due to the presence of an adhesive between the base fibers of the reinforcing fiber body. Thus, the structural member is reinforced 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.

  Therefore, the present invention can be applied to reinforcement at any location for reinforced concrete buildings, and the reinforcement body of reinforced concrete buildings and reinforced concrete buildings that improve the strength of the locations to be reinforced by simple construction. It was proposed for the purpose of providing a reinforcement method.

  The reinforcing body of a reinforced concrete building according to the present invention that achieves the above-described object is a reinforcing body having a predetermined rigidity value that is cured by impregnating an epoxy resin adhesive into a cellulose material, and reinforces a reinforced concrete building. By providing it at the target location, the reinforcement target location is reinforced with a strength greater than the standard strength. The cross-sectional area and thickness of the reinforcing body is calculated by calculating the cross-sectional area value of the reinforcing bar while calculating the insufficient strength of the reinforcement target part with respect to the standard strength specified in the current Building Standards Law by the difference in the amount of reinforcing bars. From the cross-sectional area and the thickness calculated based on the rigidity ratio with the reinforcing bar.

  The reinforcing body of the reinforced concrete building is reinforced so as to have a proof strength almost equal to the standard proof strength by supplementing the proof strength that is insufficient with respect to the reinforced target location by being provided at the reinforced target location. Reinforcements for reinforced concrete buildings are made of cellulose material, which is cheaper than carbon fibers and reinforcing fibers such as aramid fibers, etc., which are listed in the conventional method, and is soft, lightweight and easy to handle. It is also possible to provide a reinforcement target portion having a polygonal shape, an uneven shape, or the like in a state of being in close contact over the entire surface. Reinforcing bodies of reinforced concrete buildings are epoxy materials in which cellulosic materials have more OH groups than conventional reinforcing fibers, etc., 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 generated between the epoxy resin and the cellulose material, and is chemically bonded to be provided at the reinforcement target portion.

  Reinforcements for reinforced concrete buildings are hardened in the hardened state but are brittle and complement the properties of epoxy resin adhesives with the properties of chemically bonded cellulose materials. Compared with the reinforcing sheet body impregnated with epoxy resin, the portion to be reinforced is reinforced and has elasticity. Reinforcing bodies of reinforced concrete buildings are kept in close contact without being peeled off from the reinforcement target area even when the reinforcement target area is greatly shaken up and down or left and right due to an earthquake, etc. Reinforce strongly.

  In addition, the reinforcing method for a reinforced concrete building according to the present invention that achieves the above-described object has a predetermined rigidity value that is cured by impregnating a cellulosic material with an epoxy resin adhesive at a location to be reinforced of the reinforced concrete building. This is a construction method in which a reinforcing body is provided and the reinforcing object is reinforced with a strength greater than the standard strength by using this reinforcing body. Reinforcement methods for reinforced concrete buildings are calculated by, for example, calculating the insufficient strength of the reinforcement target part with respect to the standard strength stipulated in the current Building Standard Law by the difference in the amount of reinforcing bars, and converting it to the cross-sectional area value of the reinforcing bars. The cross-sectional area and the thickness are calculated based on the rigidity ratio with the reinforcing bar, and the reinforcing body is provided at the reinforcement target portion with the cross-sectional area and thickness larger than the calculated cross-sectional area and thickness.

  Reinforcement methods for reinforced concrete buildings are based on the simple work of providing a reinforcing body with a predetermined cross-sectional area and thickness at the location to be reinforced, supplementing the strength that was lacking at the location to be reinforced, and almost equivalent to the standard strength. Reinforce to be proof. 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. A cross-linked structure in which the epoxy resin is cured by polymerizing with a group is also generated between the epoxy resin and the cellulose material to form a chemically bonded reinforcing body, and this reinforcing body is provided at the location to be reinforced To do. Reinforcement method for reinforced concrete buildings is a reinforced fiber, etc., which is supplemented by the characteristics of chemically bonded cellulosic material with the characteristics of epoxy resin adhesive that has a high hardness in the cured state but is brittle, etc. The portion to be reinforced is reinforced by a reinforcing body that is stronger and more elastic than the reinforcing sheet body impregnated with an epoxy resin.

  According to the building reinforcement method according to the present invention, the epoxy resin adhesive and the cellulose material are sprayed, and the cellulose resin is impregnated with the epoxy resin adhesive in all layers, thereby exhibiting the high adhesiveness and high strength characteristics of the epoxy resin. At the same time, the brittleness of the epoxy resin is complemented by cellulose to form a resilient reinforcement body that spans between the bonding sites of the opposing structural members of the building. Therefore, according to the building reinforcement method, large-scale construction such as dismantling and recombination of structural members is not required, and it is carried out on all the structural member connection sites or wide areas of the building. It is possible to perform reinforcement that provides great resistance to force and compressive force. According to the building reinforcement method, there is almost no peeling or breakage in the formed reinforcing body even if a large force is applied to each connecting part of the structural member during an earthquake or the like. It is possible to reinforce to improve the earthquake resistance and durability by holding the part securely and firmly.

  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 is 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 spraying means 5 such as a spray gun. An 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 reinforcement construction method, the epoxy resin adhesive 3 is further sprayed onto the wound cellulose sheet body 2 by the spraying means 5 to form the reinforcement body 1, and the column body 4 is reinforced by the reinforcement body 1.

  In the reinforcing method, the epoxy resin adhesive 3 of the base adhesive layer 6 is impregnated into the cellulose sheet body 2 and cured, and the cellulose sheet body 2 is firmly bonded to the outer peripheral surface of the column body 4. In the reinforcing method, the epoxy resin adhesive 3 sprayed in the subsequent step is impregnated into the cellulose sheet body 2 and chemically bonded by the intermolecular crosslinking structure to constitute the reinforcing body 1. In the reinforcement method, the properties of the epoxy resin adhesive 3 that has a high hardness in the cured state but is brittle are complemented by the properties of the chemically bonded cellulose sheet material 2, and has a large mechanical strength against tensile and compressive forces. The column body 4 is reinforced by the reinforcing body 1 having resistance. Further, in the reinforcement method, since the reinforcing body 1 retains the appropriate elasticity of the cellulose sheet material 2, it absorbs the action force caused by the large shaking caused by the earthquake and reduces the occurrence of peeling and breakage from the column body 4. Thus, the column 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. As a result, the seismic strength is raised so that the column body 4 is substantially equal to or higher than the standard 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, a normal round steel having an outer diameter of 9 mm or more is used for the main reinforcing bar 7B and the reinforcing bar 8B, and a reinforcing bar is formed by arranging the reinforcing bar 8B at a large pitch on the outer periphery of the main reinforcing bar 7B. A concrete frame 9B is formed by embedding the main bars 7B and the band bars 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).

As shown in FIG. 4, the reinforcing body 1 is formed on the outer peripheral portion of the above-described conventional column body 4B, so that this column body 4B lacks the standard proof stress of the above-mentioned current method column body 4A. Complements strength. 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 the reinforced concrete building (column body 4A) in which the reinforcing bar specification A based on the provisions of the current Building Standard Act after 1981 is adopted as the standard (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 structure (column 4C) constructed according to the reinforcing bar specification C based on the provisions of the Building Standard Law before 1970 The strength is from Table 1 Total cross-sectional area: 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 )
Since the insufficient cross-sectional area A3C of the band 8C is reinforced by the reinforcing body 1C, the rigidity is corrected using the Young's modulus ratio (128) to obtain the required film thickness hC. Required film thickness hC = 2549 (mm ² ) × 128 ÷ 2000 (mm) = 163 (mm)
It becomes.

As described above, the reinforcing body 1C has a thickness hC of 163 mm when an allowable tensile strength value of 28 (N / mm ² ) is adopted. 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 building 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.

  Although 1st Embodiment mentioned above showed the example of application of the independent pillar body 1, this invention is not limited to this example of application. 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 a main bar and a band bar in the same manner as the column body 1 described above, and a vertical bar 18 and a horizontal bar 20 are double-barbed in the wall part, for example. Reinforcing bars are constructed.

  In the reinforcing method, since the earthquake resistant wall 12 is integrated, the reinforcing body 14 cannot be formed by winding the cellulose sheet body 2 around the outer peripheral portion like the independent column body 1 described above with respect to the column body 11. Therefore, in the reinforcing method, the reinforcing bodies 14A and 14B are provided on both sides of the earthquake-resistant wall structure 10 along the height direction across the column body 11 and the reinforcing body forming portions 12A and 12B of the earthquake-resistant wall 12 on both sides thereof. Form. In the reinforcing method, the sheet-like reinforcing bodies 14A and 14B are formed, for example, by spraying powdery cellulose 15 onto the column body 11 and the earthquake-resistant wall 12.

  The spray reinforcement method is the same as the above-described reinforcement method, in which the epoxy resin adhesive 3 is columned by the spraying means 5 in a state in which dirt and the like are removed from the surfaces of the column body 11 and the reinforcing body forming portions 12A and 12B of the earthquake resistant wall 12. The base adhesive layer 6 is formed by spraying on the surfaces of the body 11 and the earthquake-resistant wall 12. 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 powder 15 such as floor gator & cell soap) is sprayed by an appropriate spraying means 16 to form a cellulose layer.

  In the spray reinforcement method, the epoxy resin adhesive 3 of the base adhesive layer 6 is impregnated into the cellulose 15 and hardened, and the reinforcing body 14 is firmly straddled across the column body 11 and the reinforcing body forming portions 12A and 12B of the earthquake-resistant wall 12. To join. In the spray reinforcement method, the epoxy resin adhesive 3 is sprayed from the surface side of the cellulose layer by the spraying means 5 so that the cellulose resin 15 is sufficiently impregnated with the epoxy resin adhesive 3, and the epoxy resin adhesive 3 and the cellulose 15 are molecules. A chemically bonded reinforcing body 14 is formed by an intercrosslinking structure.

  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 15 and the epoxy resin adhesive 3 is repeated so as to have 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 the spray reinforcement method, the characteristics of the epoxy resin adhesive 3 that has a high hardness in the cured state but is brittle are complemented by the characteristics of the chemically bonded cellulose 15, and has a large mechanical resistance to tensile force and compressive force. The seismic wall structure 10 is reinforced by forming a reinforcing body 14 having a cross over the pillar body 11 and the seismic wall 12.

  Also in the spray reinforcement method, the reinforcing body 14 retains the appropriate elasticity of the cellulose 15, so that the acting force due to the large shaking caused by the earthquake is absorbed and the separation and breakage from the column 11 and the earthquake-resistant wall 12 occur. As a result, 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 reinforcement body 14 performs predetermined reinforcement by setting it to an optimal cross-sectional area and thickness, it is possible to make the whole thin by the width of the earthquake-resistant wall 12 site.

  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 15 which mixed the epoxy resin adhesive 3 beforehand is sprayed over the pillar 11 and the earthquake-resistant wall 12, and is reinforced. The body 14 may be formed, and the strength can be improved without impairing the seismic strength of the seismic wall 12. In addition, the reinforcing method of the earthquake resistant wall structure 10 is not limited to the spraying method of the cellulose 15. For example, the cellulose sheet 2 impregnated with the epoxy resin adhesive 3 in advance is straddled between the column 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 for the seismic wall structure 10, the reinforcing body 14 straddling the walls 12 on both sides is formed along the column body 11 as described above. However, the method is not limited to this method. . 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, a reinforcing body 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 integrated with the beam 20 similarly to the above-described seismic wall structure 10 as described above, the reinforcing body 24 is straddled between the beam 20 and the slab 21 by a spraying method or a bonding method. Form. 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. A reinforcing body 24 straddling is formed.

  In the reinforcing method of the beam 20, the reinforcing body 24 straddling the slabs 21 on both sides along the beam 20 is formed as described above. However, the method is not limited to this method. In the reinforcing method of the beam 20, a reinforcing body 24 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 15) is impregnated with the epoxy resin adhesive 3, and the characteristics of the epoxy resin adhesive 3 having a high hardness in a cured state but having brittleness are chemically treated. A reinforcing body 1 (reinforcing bodies 14 and 24) having a predetermined cross-sectional area and thickness complemented by the characteristics of the bonded cellulose sheet body 2 is formed to reinforce the structural parts of the reinforced concrete structure such as the column 4 and the beam 20. 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 an elastic 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.

Explanation of symbols

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

Claims (2)

A reinforcing body having a predetermined rigidity value cured by impregnating an epoxy resin adhesive into a cellulosic material that has a strength greater than the standard strength by providing the location to be reinforced in a reinforced concrete building. ,
Calculate the cross-sectional area and thickness based on the rigidity ratio between the cross-sectional area value and the reinforcing bar from the cross-sectional area value calculated from the cross-sectional area value of the reinforcing bar while calculating the deficit strength of the reinforcement target location with respect to the standard strength. A reinforcing body for a reinforced concrete structure, characterized in that it is formed with a value larger than the cross-sectional area and thickness. A reinforced concrete system in which a reinforcing body having a predetermined rigidity value cured by impregnating a cellulosic material with an epoxy resin adhesive is provided at a location to be reinforced in a reinforced concrete building, and the strength to be reinforced is greater than a standard proof strength. It is a method for reinforcing buildings,
Calculate the insufficient strength of the reinforcement target location with respect to the standard strength by the difference in the amount of reinforcing bars and convert it to the cross-sectional area value of the reinforcing bars,
Calculate the cross-sectional area and thickness based on the rigidity ratio with the rebar from the cross-sectional area value,
A reinforcing method for a reinforced concrete building, characterized in that the reinforcing body is provided at the location to be reinforced with a cross-sectional area and thickness larger than the calculated cross-sectional area and thickness.

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