JP6757947B2 - Seismic reinforcement method - Google Patents

Description

The present invention relates to a seismic reinforcement method.

Conventionally, earthquake-resistant reinforcement has been performed by various methods on existing reinforced concrete buildings. For example, in Patent Document 1 below, seismic reinforcement that improves the seismic strength of existing buildings by constructing a new seismic reinforcement wall made of reinforced concrete in a frame surrounded by columns and beams of an existing building. The construction method is disclosed.

Japanese Unexamined Patent Publication No. 2016-14202

However, in the conventional method of constructing a new reinforced concrete seismic reinforcement wall, the concrete sinks, so after the concrete is cast, there is no shrinkage in the gap formed between the existing beam and the top of the newly constructed concrete wall. It was necessary to place the mortar. As described above, the conventional construction method has a problem that the casting process needs to be performed twice and the construction period is long.

When the beam width of the existing beam is narrow, the distance between the end face of the reinforcement side of the existing wall (the side where the seismic reinforcement wall is constructed in the horizontal direction orthogonal to the existing wall) and the end face of the reinforcement side of the existing beam is Due to its short length, the seismic reinforcement wall with a thick wall thickness of the conventional method will protrude from the existing beams above and below to the reinforcement side. Therefore, in such a case, it is necessary to increase the number of beams so that the seismic reinforcement wall does not protrude from the upper and lower beams. In this case, for the upper beam, the non-shrink mortar wall may be extended upward so that the non-shrink mortar beam is formed on the side of the existing beam, but the lower beam (under the ceiling below the floor). For the beam), a mold must be installed on the side of the beam separately from the seismic reinforcement wall, and the non-shrink mortar beam body must be increased by filling with non-shrink mortar. In addition, since various wirings, pipes, ducts, etc. are arranged behind the ceiling, these wirings, pipes, ducts, etc. are arranged before the non-shrink mortar beam body is added to the side of the lower beam. May need to be relocated. In this way, in the conventional construction method, since the seismic reinforcement wall becomes thick, it is often necessary to increase the number of beams, and it is necessary to perform various operations other than the construction of the seismic reinforcement wall, so that the construction period becomes long. There was a risk.

The present invention has been made in view of the above points, and an object of the present invention is to provide a seismic reinforcement method for constructing a seismic reinforcement wall that can be constructed in a shorter construction period than before.

The present invention is a seismic reinforcement method for increasing the holding capacity of the building by constructing a seismic reinforcement wall in a formwork surrounded by a pair of left and right pillars and a pair of upper and lower beams of the building. An anchor mounting step of attaching a plurality of anchor members so as to project into the formwork, a bar arrangement step of arranging a plurality of reinforcing bars vertically and horizontally in the formwork, and a seismic reinforcement wall in the formwork. It consists of a formwork installation process for installing a formwork for the purpose, a cement, an expansion material, bean gravel having a particle size of more than 4 mm and 7 mm or less, and an aggregate having a particle size smaller than that of the bean gravel. A high-strength grout material having a slump flow of 500 mm or more composed of a glaut composition containing an aggregate, a cement dispersant, a thickener and a foaming agent and water has a thickness of 130 mm or less of the earthquake-resistant reinforcing wall. In the casting step of filling the beam in a range not exceeding the beam width in the beam width direction of the beam, and the plurality of high-strength grout materials filled in the formwork in the casting step are cured. A formwork disassembling step of disassembling the formwork after the curing step is provided, and the formwork setting step, the casting step, and the curing step are performed. It is characterized in that each is performed only once.

According to the present invention, the wall body of the seismic reinforcement wall is not composed of concrete as in the conventional reinforced concrete seismic reinforcement wall, but cement, expansion material, aggregate containing gravel, cement dispersant, and addition. It was decided to use a cured product of a high-strength grout material composed of a grout composition containing a viscous agent and a foaming agent and water. Since the high-strength grout material contains an expansion material and a foaming agent, it hardly sinks when cured, and has the same non-shrinkage property as non-shrinkage mortar. On the other hand, since the high-strength grout material contains bean gravel, the temperature rise due to drying shrinkage and heat of hydration of the cured product is significantly smaller than that of general non-shrinkage mortar. According to such a seismic reinforcement method, unlike the conventional reinforced concrete seismic reinforcement wall, it is not necessary to place non-shrink mortar after placing concrete, and the seismic reinforcement wall is made of only a hardened high-strength grout material. Since the wall body can be constructed, the construction period for constructing the seismic reinforcement wall can be shortened.

Further, since the gravel used in the high-strength grout material is bean gravel, the particles of the aggregate are rounded, and even if the maximum size of the aggregate is as small as 7 mm or less, the slump flow is 500 mm or more. It is possible to secure a high level of liquidity. From this, the thickness of the seismic reinforcing wall can be reduced to 130 mm or less. Therefore, even if the beam width of the existing beam is narrow and the distance between the end face on the reinforcement side of the existing wall and the end face on the reinforcement side of the existing beam is short, the seismic reinforcement wall should not protrude from the existing beam in the beam width direction. It can be constructed and it is possible to omit the additional striking of the beam by the non-shrink mortar. Therefore, it is not necessary to relocate various wirings, pipes, ducts, etc. behind the ceiling, and from such a point, the construction period for constructing the seismic reinforcing wall 10 can be significantly shortened.

As described above, according to the present invention, it is possible to provide a seismic reinforcement method capable of constructing a seismic reinforcement wall in a shorter construction period than before.

FIG. 1 is a cross-sectional view showing a frame portion of a building in which a seismic reinforcing wall according to the first embodiment of the present invention is constructed. FIG. 2 is a cross-sectional view showing a frame portion of a building in which a seismic reinforcing wall according to the first embodiment of the present invention is constructed. FIG. 3 is a cross-sectional view showing a frame portion of a building in which a seismic reinforcing wall is constructed by a conventional construction method. FIG. 4 is a process chart showing the processes of each method in chronological order in order to compare the processes and construction periods of the conventional method and the seismic reinforcement method (this method) according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are merely preferred embodiments and are not intended to limit the scope of the invention, its applications, or its uses.

<< Embodiment 1 >>
As shown in FIGS. 1 and 2, the seismic reinforcement wall 10 is constructed in a frame 3 composed of a pair of left and right columns 1 and a pair of upper and lower beams 2 of an existing reinforced concrete building. In the first embodiment, an existing reinforced concrete wall 4 is constructed in the frame 3, and the seismic reinforcement wall 10 is additionally struck along the existing wall 4 to reinforce the existing wall 4. Is.

The earthquake-resistant reinforcing wall 10 includes a plurality of anchor members 11, a plurality of reinforcing bars 12, a split reinforcing bar 13, and a wall body 14.

The anchor member 11 is for integrating the existing wall 4 to be seismically reinforced with the wall body 14 of the newly installed seismic reinforcement wall 10. The anchor member 11 is attached to the frame 3 and is provided so as to project into the frame 3. Specifically, for each of the pair of columns 1 and the pair of beams 2, a plurality of anchor members 11 are embedded in the column 1 or the beam 2 on the tip side of the anchor reinforcement, and the remaining portion is inside the frame 3. It is attached so that it protrudes into the. The remaining portion of each anchor member 11 that is not embedded in the column 1 or the beam 2 is included in the wall body 14. A plurality of anchor members 11 are provided at predetermined intervals for each of the pillar 1 and the beam 2.

The plurality of reinforcing bars 12 are composed of a plurality of vertical bars 12a extending in the vertical direction and a plurality of horizontal bars 12b extending in the horizontal direction. The plurality of vertical bars 12a and the plurality of horizontal bars 12b are arranged in a grid pattern in the frame 3 and are included in the wall body 14. The plurality of vertical bars 12a are arranged at predetermined intervals in the horizontal direction from the left end to the right end in the frame 3. The plurality of horizontal bars 12b are arranged at predetermined intervals in the vertical direction from the upper end to the lower end in the frame 3.

The split reinforcing muscle 13 is composed of a spiral muscle. The split reinforcing bar 13 is installed at a joint portion with the frame 3, that is, at the outer edge portion of the seismic reinforcing wall 10. The split reinforcing bar 13 is provided so as to face each of the pair of columns 1 and the pair of beams 2, and is included in the wall body 14.

The wall body 14 is made of a hardened product of a high-strength grout material, and is formed so as to include a portion of the anchor member 11 in the frame 3 and a reinforcing bar 12 and a split reinforcing bar 13 in the frame 3. The wall body 14 is formed so that the thickness is 130 mm or less. Specifically, in the present embodiment, the wall body 14 is formed to have a thickness of 125 mm. The high-strength grout material constituting the wall body 14 is constructed by adding water to a premix grout composition in which cement, an expansion material, an aggregate, a cement dispersant, a thickener and a foaming agent are premixed and kneading them. Manufactured on site. In this embodiment, a high-strength grout material produced by kneading 100 parts by mass of the premix grout composition with water of 8 parts by mass or more and 20 parts by mass or less is used.

The cement contained in the premix grout composition may be any hydraulic cement. The content of cement in the premix grout composition is preferably 20% by mass or more and 35% by mass or less. This is because if it is less than 20% by mass, the strength development is inferior (compressive strength is small), and if it exceeds 35% by mass, the drying shrinkage becomes large or the temperature rise due to heat of hydration becomes large.

The expansion material contained in the premix grout composition can be any expansion material as long as it contains a substance having a large bulk volume due to the growth of hydrate crystals such as calcium hydroxide and ettringite by hydration. However, those conforming to JIS A6202 "Expansion material for concrete" are particularly preferable because the expansion rate with respect to the mixing amount is stable. The content of the expanding material in the premix grout composition is preferably 1% by mass or more and 7% by mass or less. This is because if it is less than 1% by mass, the effect of the expanding material is difficult to obtain and the shrinkage becomes large, and if it exceeds 7% by mass, the strength may decrease in the unrestrained portion.

The thickener contained in the premix grout composition is not particularly limited, and at least one such as water-soluble cellulose, polysaccharide, polyvinyl compound, alkyl starch, and starch ether can be used. Further, the thickener is preferably a powder (powder thickener) because it is easy to premix. The content of the thickener in the premix grout composition is preferably 0.0002% by mass or more and 0.02% by mass or less. If it is less than 0.0002% by mass, the effect of containing the thickener is difficult to obtain and the material separation resistance becomes low, and if it exceeds 0.02% by mass, the fluidity deteriorates and there is a risk of a large delay in a low temperature environment. Because there is.

The cement dispersant contained in the premix grout composition is not particularly limited, and a water reducing agent, a high-performance water reducing agent, an AE water reducing agent, a high-performance AE water reducing agent, a fluidizing agent and the like can be used, and premixing is easy. Therefore, a powdered one (powdered cement dispersant) is preferable. It is more preferable to use a powdered high-performance water reducing agent or a powdered high-performance AE water reducing agent as a cement dispersant because the compressive strength of grout mortar at 28 days is easily set to 45 N / mm ² or more. The content of the cement dispersant in the premix grout composition is preferably 0.03% by mass or more and 3% by mass or less because high fluidity can be obtained and it is difficult to separate the materials.

The foaming agent contained in the premix grout composition is not particularly limited as long as it is a powder foaming agent, and may be any powder that generates a gas after kneading with water. By this foaming action, the sinking phenomenon of the grout mortar can be prevented, and the grout mortar can be more integrated with the existing members such as the existing wall 4, the existing pillar 1 and the beam 2. That is, non-shrinkage is obtained. The content of the foaming agent in the premix grout composition is preferably 0.0002% by mass or more and 0.03% by mass or less. This is because if it is less than 0.0002% by mass, it is difficult to obtain the effect of the foaming agent, and if it exceeds 0.03% by mass, the expansion becomes excessive, especially in a high temperature environment, and there is a concern that the compressive strength may decrease.

The aggregate contained in the premix grout composition contains bean gravel having a particle size of more than 4 mm and 7 mm or less. In addition to bean gravel, the aggregate contains aggregate having a particle size smaller than that of bean gravel. As the aggregate having a small particle size, for example, river sand, land sand, sea sand, crushed sand, silica sand, artificial aggregate, slag aggregate and the like can be used. As the aggregate, a lightweight aggregate having a large water absorption rate is not very preferable because the drying shrinkage becomes large.

The aggregate preferably has a bean gravel content of 15% by mass or more and 45% by mass or less. If the content of bean gravel is less than 15% by mass, the temperature rise due to drying shrinkage and heat of hydration becomes large, and if it exceeds 45% by mass, the material separation resistance is inferior and bleeding is likely to occur, which is not preferable. .. It is more preferable that the aggregate has a bean gravel content of 16% by mass or more and 40% by mass.

Further, since the aggregate is easy to obtain high fluidity and is excellent in material separation resistance, the content of particles having a particle size of more than 0.3 mm and 4 mm or less is 40% by mass or more and 65% by mass or less, and particles. The content of particles with a diameter of more than 0.3 mm and 2.5 mm or less is 30% by mass or more and 55% by mass or less, and the content of particles with a particle size of 0.3 mm or less is 1% by mass or more and 45% by mass or less. The content of particles having a particle size of 0.15 mm or less is preferably 10% by mass or less.

Dry shrinkage occurs when the content ratio (a / B) of the bone material amount (a) to the mass (B) of the binder contained in the premix grout composition is 1.8 or more and 3.0 or less in terms of mass ratio. It is preferable because it is small, it is difficult to separate the material, and the temperature rise due to heat of hydration is small. If it is less than 1.8, the unit cement amount increases, so that the effect of reducing drying shrinkage and the effect of suppressing hydration heat generation become poor, and if it exceeds 3.0, the material separation resistance is inferior and the possibility of bleeding increases. Because. It is more preferable that the a / B is 2.2 or more and 2.6 or less because the drying shrinkage is small, the material is difficult to separate, and the temperature rise due to heat of hydration is small. Here, the binder (B) includes cement, gypsum, pozzolan such as silica fume and metakaolin, latent hydraulic substances such as blast furnace slag powder, and expansion material.

As described above, the seismic reinforcing wall 10 of the first embodiment is a hardened product of a high-strength grout material in which the wall body 14 made of concrete in the conventional construction method is made of the premix grout composition and water. It is composed of. As described above, since the high-strength grout material contains an expansion material and a foaming agent, it hardly sinks when it is cured, and has the same non-shrinkage property as that of non-shrink mortar. On the other hand, since the high-strength grout material contains bean gravel, the temperature rise due to drying shrinkage and heat of hydration of the cured product is significantly smaller than that of general non-shrinkage mortar. Therefore, in the conventional method, since the concrete sinks, as shown in FIG. 3, after the concrete wall body 20 is placed, non-shrink mortar is injected between the concrete wall body 20 and the existing beam 2. The non-shrink mortar wall 30 was cast, and the concrete wall 20 and the non-shrink mortar wall 30 formed the wall body of the seismic reinforced wall. However, in the first embodiment, the hardening of the high-strength grout material is performed. The wall body 14 of the seismic reinforcing wall 10 can be formed only by objects.

It has been confirmed by a compressive strength test of 28 days of age that the cured product of the high-strength grout material having the above-mentioned composition has a high compressive strength of 50 N / mm ² or more. This compressive strength is more than twice the compressive strength (about 24 N / mm ² ) of "ready-mixed concrete" specified in JIS A5308. Therefore, by forming the wall body 14 of the earthquake-resistant reinforcing wall 10 with a cured product of such a high-strength grout material having extremely high compressive strength, the wall body can be formed by the concrete wall body 20 and the non-shrink mortar wall body 30. It is possible to construct a seismic reinforced wall 10 having a wall thickness t1 (see FIG. 2) thinner than the constructed seismic reinforced wall by the conventional construction method and having the same proof stress.

Specifically, as shown in FIG. 3, the wall thickness t2 of the seismic reinforcement wall of the conventional method is 250 mm, whereas according to the seismic reinforcement wall 10 of the present embodiment, the wall of the seismic reinforcement wall of the conventional method is used. It is possible to construct a seismic reinforcing wall 10 having the same proof stress with a wall thickness t1 (= 125 mm) that is half the thickness t2.

-Seismic reinforcement method-
In the following, a seismic reinforcement method for increasing the yield strength of an existing building by constructing the seismic reinforcement wall 10 in the frame 3 based on the process chart of FIG. 4 will be described. In the process chart of FIG. 4, the construction period (day) is shown in the upper row, the processes of the conventional construction method are shown in chronological order in the middle row, and the processes of the seismic reinforcement construction method (this construction method) according to the present invention are shown in chronological order in the lower row. It is shown in order.

As shown in FIG. 4, the seismic reinforcement method includes an anchor mounting process, a bar arrangement process, a formwork installation process, a sealing process, a placing process, a curing process, and a formwork dismantling process. .. The anchor attachment process, the bar arrangement process, the formwork installation process, the sealing process, the placing process, the curing process, and the formwork dismantling process are performed in this order.

In the anchor attachment step, a plurality of anchor members 11 are attached to the pair of columns 1 and the pair of beams 2 constituting the frame 3 so as to project into the frame 3. Specifically, for each of the pair of columns 1 and the pair of beams 2, a plurality of anchor members 11 are embedded in the column 1 or the beam 2 on the tip side of the anchor reinforcement, and the remaining portion is inside the frame 3. Attach it so that it protrudes into the.

In the bar arrangement step, a plurality of reinforcing bars 12 are arranged vertically and horizontally in the frame 3. Specifically, a plurality of vertical bars 12a are arranged in the frame 3 from the left end to the right end at predetermined intervals in the horizontal direction, and a plurality of horizontal bars 12b extending in the horizontal direction are arranged from the upper end to the lower end in the frame 3. Arrange at predetermined intervals in the vertical direction toward. Further, in the first embodiment, in the reinforcing bar arrangement step, the split reinforcing bar 13 is arranged at the joint portion (outer edge portion of the seismic reinforcing wall 10) with the frame 3 of the seismic reinforcing wall 10.

In the formwork installation step, a formwork for forming the wall body 14 including the plurality of reinforcing bars 12 arranged in the above-mentioned bar arrangement step is installed. The formwork should be such that the thickness of the seismic reinforcement wall 10 is 130 mm or less, and the high-strength grout material does not exceed the beam width w in the beam width direction of the pair of beams 2 in the subsequent casting process. Installed to be filled. The formwork is provided with an injection hole for injecting the high-strength grout material constituting the wall body 14 and a plurality of air vent holes.

In the sealing process, the gap between the connecting portions of the plate-shaped members constituting the formwork is filled with the sealing member to prevent the high-strength grout material from leaking from the gap in the casting process.

In the casting process, a high-strength grout material is filled into the mold through the injection holes formed in the mold installed in the mold installation process using a grout pump. At this time, the high-strength grout material is filled by the formwork in a range not exceeding the beam width w in the beam width direction of the pair of beams 2 so that the thickness of the seismic reinforcing wall 10 is 130 mm or less. .. As described above, the high-strength grout material is produced by kneading the premix grout composition and water with a mixer at the construction site. In the present embodiment, a high-strength grout material produced by kneading 100 parts by mass of the premix grout composition with water of 8 parts by mass or more and 20 parts by mass or less is injected.

In the curing step, the high-strength grout material cast in the casting step is cured without giving vibration.

In the formwork dismantling step, when the high-strength grout material is hardened, the curing step is completed and the formwork is dismantled.

Through the above steps, the seismic reinforcing wall 10 along the existing wall 4 is constructed in the frame 3. As described above, in the seismic reinforcement method according to the present invention, the casting process can be performed only once. Therefore, by placing concrete and non-shrink mortar, the construction period can be shortened as compared with the conventional construction method in which it is necessary to perform the casting process twice.

Specifically, as shown in FIG. 4, the conventional construction method includes an anchor mounting process, a bar arrangement process, a first mold installation process, a first casting process, a first curing process, and a second mold. It includes a frame installation process, a sealing process, a second placing process, a second curing process, and a mold dismantling process.

The first formwork installation process is a process of installing a formwork for placing concrete, the first placing process is a process of placing concrete, and the first curing process is a process of hardening concrete. is there. On the other hand, the second mold setting step is a step of installing a mold for placing a non-shrink mortar, the second casting step is a step of placing a non-shrink mortar, and the second curing step is a step of placing a non-shrink mortar. This is a process of curing non-shrink mortar.

As shown in FIG. 3, in the conventional construction method, in the first placing step, the concrete wall body 20 up to a height of 200 mm below the existing beam 2 is placed, and then the concrete wall body 20 and the existing beam 2 are combined. A non-shrink mortar is injected between them to drive the non-shrink mortar wall 30.

As described above, in the conventional method, in order to place concrete and non-shrink mortar, it is necessary to perform the formwork setting process, the placing process, and the curing process twice. On the other hand, in the seismic reinforcement method (this method) according to the present invention, the formwork installation process, the placing process, and the curing process need to be performed only once, so that the construction period can be significantly shortened. In FIG. 4, according to this construction method, the construction period can be shortened by 3 days as compared with the conventional construction method.

Further, as shown in FIG. 3, when the beam width w of the existing beam 2 is narrow, the end face of the existing wall 4 on the reinforcing side (the side on which the seismic reinforcing wall 10 is constructed in the horizontal direction orthogonal to the existing wall 4). Since the distance w1 between the beam and the end face of the existing beam 2 on the reinforcing side is short, the seismic reinforcing wall with a thick wall thickness t2 of the conventional method protrudes from the upper and lower existing beams 2 to the reinforcing side. Therefore, in such a case, it is necessary to increase the number of beams 2 by the width Δw so that the seismic reinforcing wall does not protrude from the upper and lower beams 2. In this case, with respect to the upper beam 2, the non-shrink mortar wall 30 may be extended upward so that a non-shrink mortar beam having a width Δw is formed on the side of the existing beam 2, but the lower beam For 2 (beam 2 behind the ceiling 5 downstairs), a mold is installed on the side of the beam 2 separately from the seismic reinforcement wall, and a non-shrink mortar is filled to form a non-shrink mortar beam 40. Must be increased. Further, since various wirings, pipes, ducts, etc. are arranged on the back of the ceiling 5, these wirings, pipes, and the like are arranged before the non-shrink mortar beam body 40 is added to the side of the lower beam 2. , Ducts, etc. may need to be relocated. In this way, in the conventional construction method, since the seismic reinforcement wall becomes thick, it is often necessary to increase the number of beams, and it is necessary to perform various operations other than the construction of the seismic reinforcement wall, so that the construction period becomes long. There was a risk.

On the other hand, in the seismic reinforcement method (this method) according to the present invention, as described above, it is possible to construct the seismic reinforcement wall 10 having a thinner wall thickness and the same proof stress as the seismic reinforcement wall by the conventional method. .. Specifically, the thickness t1 of the seismic reinforcing wall 10 can be reduced to 130 mm or less. Therefore, in this construction method, it is possible to omit the additional striking of the beam 2 by the non-shrink mortar in the casting process, and it is not necessary to perform various operations associated with the additional striking of the beam. Can be shortened.

-Effect of Embodiment 1-
As described above, according to the first embodiment, the wall body 14 of the seismic reinforcement wall 10 is not made of concrete like the conventional reinforced concrete seismic reinforcement wall, but is made of cement, expansion material, and gravel. It was decided to construct a cured product of a high-strength grout material composed of a premix grout composition containing an aggregate containing an aggregate, a cement dispersant, a thickener and a foaming agent, and water. Since the high-strength grout material contains an expansion material and a foaming agent, it hardly sinks when cured, and has the same non-shrinkage property as non-shrinkage mortar. On the other hand, since the high-strength grout material contains bean gravel, the temperature rise due to drying shrinkage and heat of hydration of the cured product is significantly smaller than that of general non-shrinkage mortar. Therefore, in the conventional method, since the concrete sinks, as shown in FIG. 3, after the concrete wall body 20 is placed, non-shrink mortar is injected between the concrete wall body 20 and the existing beam 2. The non-shrink mortar wall 30 was cast, and the concrete wall 20 and the non-shrink mortar wall 30 formed the wall body of the seismic reinforced wall. However, in the first embodiment, the hardening of the high-strength grout material is performed. The wall body 14 of the seismic reinforcement wall 10 can be formed only by objects. Therefore, according to the seismic reinforcement method (this method) for constructing such a seismic reinforcement wall 10, the non-shrink mortar wall 30 made of non-shrink mortar is placed after the concrete wall 20 is placed as in the conventional method. It is not necessary to do so, and the construction period for constructing the seismic reinforcing wall 10 can be significantly shortened. Therefore, according to the first embodiment, it is possible to provide a seismic reinforcement construction method capable of constructing the seismic reinforcement wall 10 in a shorter construction period than the conventional one.

Further, according to the first embodiment, a hardened product of a high-strength grout material having a compressive strength more than twice the compressive strength (about 24 N / mm ² ) of the "ready-mixed concrete" specified in JIS A5308 is used as a seismic reinforcing wall. Since the wall body 14 of 10 is configured, it is possible to construct the seismic reinforcing wall 10 having a wall thickness t1 thinner than that of the seismic reinforcing wall by the conventional construction method and having the same strength. Further, since the gravel used in the high-strength grout material is bean gravel, the particles of the aggregate are rounded, and even if the maximum size of the aggregate is as small as 7 mm or less, the slump flow is 500 mm or more. It is possible to secure a high level of liquidity. From this, the thickness of the seismic reinforcing wall 10 can be reduced to 130 mm or less. Therefore, even if the beam width w of the existing beam 2 is narrow and the distance w1 between the end face on the reinforcing side of the existing wall 4 and the end face on the reinforcing side of the existing beam is short, the seismic reinforcing wall 10 is moved from the existing beam 2 in the beam width direction. It can be constructed so that it does not protrude, and it is possible to omit the additional striking of the beam by the non-shrink mortar. Therefore, it is not necessary to relocate various wirings, pipes, ducts, etc. behind the ceiling, and from such a point, the construction period for constructing the seismic reinforcing wall 10 can be significantly shortened.

Further, according to the first embodiment, as described above, since it is possible to construct the seismic reinforcement wall 10 having a wall thickness t1 thinner than that of the seismic reinforcement wall by the conventional construction method and having the same proof stress, it is possible to construct a multi-story building. When seismic reinforcement of an object is performed, the weight increase of the building due to the seismic reinforcement can be reduced. By reducing such an increase in weight, the amount of reinforcement of the entire building can be reduced, so that the cost for seismic reinforcement can be reduced.

Further, according to the first embodiment, as described above, hardening of a high-strength grout material having a compressive strength more than twice the compressive strength (about 24 N / mm ² ) of the “ready-mixed concrete” defined in JIS A5308. Since it was decided to construct the wall body 14 of the seismic reinforcement wall 10 with an object, when performing seismic reinforcement of a multi-story building, the seismic reinforcement wall 10 should be constructed with the same wall thickness as the seismic reinforcement wall by the conventional construction method. As a result, the number of reinforcement points can be reduced, so that the cost for seismic reinforcement can be reduced.

Further, since a large amount of concrete is used in the conventional construction method, it is necessary to dispatch a large vehicle such as a concrete pump truck. However, according to the first embodiment, water is added to the premix grout composition and kneaded. Since high-strength grout material manufactured at the construction site is used, it is not necessary to dispatch a large vehicle. Further, since the high-strength grout material can be manufactured near the seismic reinforcing wall 10 to be added, it is not necessary to transport the high-strength grout material. Therefore, according to the seismic reinforcement wall 10 and the seismic reinforcement method of the first embodiment, it is easy for buildings with a narrow site, buildings with heavy traffic on surrounding roads, and buildings for which concrete casting design is difficult, and high-rise buildings. Can be constructed in.

<< Other Embodiments >>
In the first embodiment, the seismic reinforcement method for constructing the seismic reinforcement wall 10 along the existing wall 4 in the frame 3 has been described, but the seismic reinforcement wall according to the present invention and the seismic reinforcement method for constructing the same are described above. It is not limited to the one, and can be applied to the case where a new seismic reinforcing wall 10 is added to the frame 3.

As described above, the present invention is useful for the seismic reinforcement method.

1 pillar
2 beams
3 Framing
4 Existing wall
10 Seismic reinforcement wall
11 Anchor member
12 rebar
14 wall body

Claims (2)

This is a seismic reinforcement method that increases the holding capacity of the building by constructing a seismic reinforcement wall in the frame surrounded by a pair of left and right columns and a pair of upper and lower beams of the building.
Anchor mounting process of mounting a plurality of anchor members on the frame so as to project into the frame,
Reinforcing bar arrangement process in which a plurality of reinforcing bars are arranged vertically and horizontally in the above frame, and
The formwork installation process of installing the formwork for constructing the earthquake-resistant reinforcing wall in the frame, and
In the above mold, cement, expansion material, aggregate consisting of bean gravel having a particle size of more than 4 mm and 7 mm or less and aggregate having a particle size smaller than the bean gravel, cement dispersant, thickener and foaming agent A high-strength grout material composed of a grout composition containing the above-mentioned material and water so as to have a slump flow of 500 mm or more is provided in the beam width direction of the beam so that the thickness of the seismic reinforcing wall is 130 mm or less. The casting process to fill the area not to exceed the width,
In the casting step, the high-strength grout material filled in the formwork is cured to form a wall body containing the plurality of reinforcing bars, and a curing step.
After the curing step, a mold dismantling step of disassembling the mold is provided.
A seismic reinforcement method characterized in that the formwork installation process, the casting process, and the curing process are performed only once. In claim 1,
The seismic reinforcement method is characterized in that, in the casting process, the high-strength grout material is filled into the formwork without additional striking of the beam with non-shrink mortar.

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