JP2013047456A - Construction method for bar arrangement of concrete beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bar arrangement method of a concrete beam with which aspects of reducing the amount of reinforcing-bars to be used and simplifying arrangement of bars are improved, further, a delivery time can be shortened, a quality can be stabilized and costs can be reduced by fixing a size without incurring problems in a structure specification, strength and reliability relating to a reinforcement joint position.SOLUTION: A bar arrangement method is applied to a reinforcement concrete beam 3 or a steel reinforcement concrete beam provided along with a load-bearing wall 1. An upper end bar 12 and a lower end bar 13 are comprised of a pair of reinforcing-bars A, Awith diameter expanded heads disposed in both ends of the beam and an intermediate reinforcing-bar B joined to these reinforcing-bars. Each of the reinforcing-bars Aand Awith the diameter-expanded heads has a diameter-expanded head Aa in one end and this diameter-expanded head Aa is buried in concrete of a reinforcement concrete column 2. Two to four types of the reinforcing-bars A, Awith diameter-expanded heads are prepared for each reinforcement diameter at a reinforcing-bar manufacturer side as fixed-size standard products.

Description

  The present invention relates to a reinforcing bar arrangement method for concrete beams in a reinforced concrete building or a steel reinforced concrete building which is an apartment house or the like.

In general, as shown in FIGS. 12 (A) and 12 (B), the ends of the main bars 62 and 63 of the reinforced concrete beam 53 are bent portions 62a and 63a extending in the vertical direction in order to ensure fixing to the column concrete. It is set as the structure which provided. FIG. 4A shows an example of an intermediate floor and a top floor with protruding capitals, and FIG. 4B shows an example of an intermediate floor.
Such rebar assembly is generally performed at a factory for each building by cutting it at a factory, bending it, carrying it to the site, and then assembling it.
However, the bent portion at the end of the main reinforcing bar causes an increase in the amount of reinforcing bars to be used, enters into the reinforcing bar constituting the column made of reinforced concrete, and the reinforcing bar in the column becomes complicated.

As a method of solving such a problem, as shown in FIG. 13, a reinforcing bar having enlarged heads 62b and 63b at both ends is used, and fixing instead of the bent parts 62a and 63a is performed by the enlarged heads 62b and 63b. Construction methods that give strength have been proposed and put into practical use (for example, Patent Documents 1 and 2). This method is called a T-head rebar method or a mechanical rebar fixing method.
The processing of the expanded head of the above-mentioned expanded diameter head rebar is performed by heating the end of the material rebar with dimensions slightly longer than the length used for the beam by high-frequency induction heating, etc., and press-molding it. Done. In this case, since there are various problems in equipment and the length of the required reinforcing bar varies depending on the building property, after processing the enlarged head at one end, the reinforcing bar material is swung 180 degrees and inverted, and the same equipment is used. Process the enlarged head at the other end.

JP 11-293850 A JP 2000-257209 A

The construction method using the reinforcing bar with the enlarged head is an excellent construction method in terms of reducing the amount of reinforcing bars used, simplifying the reinforcement, and reducing overcrowded reinforcement.
However, the heads 62b and 63b have enlarged diameters at both ends, and different lengths are required for each property of the building and for each part of the building used. For this reason, after the bar arrangement of the building is completed, an order is made to the reinforcing bar manufacturer, and the production is made to order.
The processing of the enlarged diameter heads 62b and 63b at the reinforcing bar manufacturer requires the process of expanding the diameter by induction heating and pressurizing processes as described above after manufacturing the reinforcing bar material of the required size, which is a time-consuming process. It becomes. Therefore, it takes time from order receipt to delivery, which hinders the shortening of the construction period of the building. Since it is a made-to-order production, production planning is difficult, and there is also a problem that the operating rate of the processing equipment is lowered due to the uneven ordering time, resulting in uneconomical. Moreover, since a long rebar is handled, and both ends are sequentially processed by swinging 180 °, a large occupied floor area is required at a processing place. Processing of such a long rebar head of a long rebar is difficult to automate and it is difficult to ensure quality.

Therefore, the present inventor has improved the problem of the long-diameter head-reinforcing bar having a different length for each property, and has a constant-diameter head having an enlarged head only at one end. We considered using a reinforcing bar.
However, it is stipulated in the structural regulations that a general rebar joint of a large beam is performed at a location where stress is small. For example, as shown in FIGS. 14A and 14B, in both the gas pressure welding joint and the lap joint, the upper bar is in the range of L0 / 2 at the center of the beam, and the lower bar is L0 from the column to the beam formation D. / 4.

Therefore, it is expected that there are many cases that cannot be handled depending on the property of the building when the reinforcing bar with the enlarged diameter head is used. Therefore, it is difficult to obtain the advantage of scaling.
Conventionally, since there is such a structural definition of the position of the reinforcing bar joint, the concept of sizing is not made in the reinforcing bar with an enlarged head. Conventionally, in the case of reinforcing bars having bent portions 62a and 63a as in the example of FIG. 12, there is a construction method in which the reinforcing bars are pre-assembled before being brought into the field, but they are cut and processed in advance regardless of the property. There are no reinforcing bars. Thus, conventionally, there is neither an idea nor an example for sizing the beam main bar.

  The purpose of this invention is to use a reinforcing bar with an enlarged head, to reduce the amount of reinforcing bars used, and to simplify the arrangement of the reinforcing bars. The purpose is to provide a method for laying concrete beams that can standardize production by standardization, stabilize quality, shorten delivery times, and reduce costs without causing reliability problems.

The reinforcing method for concrete beams according to the present invention is a method for constructing reinforcing bars for reinforced concrete beams or steel reinforced concrete beams provided along a bearing wall, and each reinforcing bar is a reinforcing bar extending in the beam length direction. Each of the upper and lower bars constituting the pair of reinforcing bars with an enlarged head arranged at both ends of the beam, and an intermediate reinforcing bar having both ends joined to the pair of reinforcing bars with an enlarged head via reinforcing bar joints. The pair of rebars with an enlarged head have an enlarged head at one end, and the enlarged head is embedded in the concrete of a reinforced concrete column or a steel reinforced concrete column adjacent to the load-bearing wall. In addition, the reinforcing bar with an enlarged head is selected from reinforcing bars with an enlarged head that have been standardized as 2 to 4 types of standard bars for each reinforcing bar thickness. .
In this specification, the “bearing wall” includes a “seismic wall”.

  In the bar arrangement method according to the present invention, each of the upper and lower reinforcing bars constituting the main reinforcing bar includes a reinforcing bar with an enlarged head at one end of the upper reinforcing bar and an reinforcing bar with an enlarged head at the other end of the lower reinforcing bar, respectively. Further, the reinforcing bars with the enlarged heads on the same end side of the upper end and the lower end may be different in length from each other.

  Moreover, in the bar arrangement method of this invention, each rebar in a plurality of reinforced concrete beams or steel reinforced concrete beams in one building is composed of the pair of rebars with an enlarged head and the intermediate rebar, In these multiple reinforced concrete beams or steel reinforced concrete beams, the positions corresponding to each other, that is, the reinforcing bars with enlarged heads in the same position in the longitudinal direction, vertical direction, and width direction in each beam are mutually the same. You may use the thing of length.

  According to the reinforcement construction method for concrete beams with this configuration, the use of reinforcing bars with enlarged heads reduces the amount of reinforcing bars used compared to the use of reinforcing bars with bent parts, and the reinforcement in the column Simplified. Reinforcing bars with enlarged heads are used, but the main reinforcing bar is a pair of reinforcing bars with enlarged heads arranged at both ends of the beam, and a pair of reinforcing bars with enlarged heads joined at both ends via reinforcing bar joints. Since it is made of a reinforcing bar, it is possible to use a standard length, that is, a standardized reinforcing bar with an enlarged head. This makes it easy to automate the production line, making it possible to reduce costs and ensure consistent quality through thorough automation, and contribute to shortening the construction period of the building by shortening the delivery time.

  Reinforcing bars with an enlarged head are joined by intermediate reinforcing bars and reinforcing steel joints, but the present invention is applied to reinforced concrete beams or steel reinforced concrete beams provided along the bearing walls. There is no problem of touching the structure rules, and there is no problem in structural strength. The arrangement of the reinforcing bar joints defined in the structural regulations is a provision for general beams not adjacent to the bearing walls. In the case of reinforced concrete beams and steel reinforced concrete beams installed along the bearing walls, many stresses are borne by the bearing walls, so the reinforcement of the reinforcing bars in the beams is a problem in terms of strength and reliability. In addition, there is no problem that conflicts with the structure regulations. In other words, in the past, for reinforced concrete beams provided along the bearing walls, it was ensured that the position of the rebar joint was set to the same position as a general large beam, or a single continuous rebar without joints to ensure strength reliability. In terms of this, it is a wasteful overdesign. In addition, it is difficult to improve the quality of long rebars having enlarged heads at both ends due to difficulty in automation. This invention has been reviewed and optimized for such overdesign, so standardization of production by standardization, quality stabilization, and shortening of delivery time while ensuring strength and reliability. Cost reduction is possible.

  For each of the upper and lower reinforcements constituting the main reinforcement, the reinforcing bar with the enlarged head at one end of the upper reinforcement and the reinforcing bar with the enlarged head at the other end of the lower reinforcement are of the same length. If the length of the reinforcing bar with the enlarged head on the same end side of the upper and lower reinforcing bars is different from each other, two types of reinforcing bars with an enlarged head are prepared. The positions of the joints of the lower end bars can be shifted from each other. In addition, by using the above-described two types of rebars with an enlarged head, intermediate reinforcing bars having the same length can be used for both the upper and lower reinforcing bars, resulting in excellent productivity.

  Each main reinforcing bar in a plurality of reinforced concrete beams or steel reinforced concrete beams in one building is composed of the pair of reinforcing bars with an enlarged head and the intermediate reinforcing bars, and the plurality of reinforced concrete beams or steel reinforced concrete beams are mutually connected. When using the same length of reinforcing bars with enlarged heads in the corresponding positions, that is, in the longitudinal direction, vertical direction, and width direction in each beam, in the same building The number of types of reinforcing bars with an enlarged head can be reduced. For this reason, productivity improves further.

  The reinforcing bar construction method of the present invention is a method for constructing a reinforcing bar for a reinforced concrete beam or a steel-framed reinforced concrete beam provided along a load-bearing wall, and each of the main reinforcing bars that are reinforcing bars extending in the beam length direction. The upper and lower bars are composed of a pair of rebars with enlarged heads arranged at both ends of the beam, and intermediate rebars whose ends are joined to the pair of rebars with enlarged heads via rebar joints, The pair of rebars with an enlarged head have an enlarged head at one end, and the enlarged head is embedded in the concrete of a reinforced concrete column or a steel reinforced concrete column adjacent to the load-bearing wall. Since the rebar with diameter head is selected from 2 to 4 types of rebar with standardized diameter for each rebar thickness, the amount of rebar used can be reduced and distributed. Excellent in terms of muscle simplification Furthermore, the structure according to the reinforcing bar joint position defined intensity, without causing reliability problems, standardization of production by standard dimension of quality stabilization, delivery time, it is possible to reduce costs. In particular, since the reinforcing bar with a diameter head is selected from a plurality of reinforcing bars with a diameter-enlarged head that are standardized as a standard, the advantage of the above-mentioned scaling can be obtained more clearly.

(A) is a fracture front view of a reinforcing bar showing a reinforced concrete beam and its peripheral structure to be constructed by the reinforcing bar construction method according to one embodiment of the present invention, (B) is a partially enlarged view of FIG. C) is an explanatory view of the upper and lower streaks. It is a fracture perspective view which shows the reinforced concrete beam of FIG. 1, and its surrounding structure. It is a schematic horizontal sectional view which shows an example of the apartment house building using the same reinforced concrete beam. It is explanatory drawing which shows the example of the kind of reinforcing bar with a diameter-expansion head prepared. It is an enlarged side view which shows the diameter expansion head vicinity of the reinforcing bar with an diameter expansion head. (A), (B) is explanatory drawing which shows each example of a rebar joint, respectively. It is explanatory drawing which shows the junction part of a reinforcing bar joint. (A)-(C) are the partial expanded fracture side views which show the modification of the reinforcing bar with an enlarged diameter head, respectively. It is a schematic horizontal sectional view which shows each modification of the building to which the same reinforced concrete beam is applied. It is a front view of the bar arrangement which shows the relationship between the column in the middle of a beam, and a reinforcing bar. It is a fracture front view showing a steel frame reinforced concrete beam according to another embodiment of the present invention and its peripheral structure. It is explanatory drawing of a prior art example. It is explanatory drawing of another prior art example. It is explanatory drawing of structure prescription | regulation.

  An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1 (A), this concrete beam arrangement method is applied to a reinforced concrete beam 3 provided between columns 2 on both sides along a bearing wall 1. This bearing wall 1 is a seismic wall. The bearing wall 1 and the column 2 are both reinforced concrete, and the wall concrete 4 (FIG. 2) and the column concrete 5 are continuously placed with the beam concrete 6 of the beam 3. The column 2 has column main bars 7 and band bars 8 as reinforcing bars. The load-bearing wall 1 is provided with reinforcing bars 9 in a mesh shape in the vertical and horizontal directions.

  FIG. 3 is a schematic horizontal sectional view of a multi-storey reinforced concrete apartment building 11. In this apartment house building 11, each dwelling space 10 arranged in the girder direction is partitioned by a load-bearing wall 1 as a door wall extending in the wife direction. The reinforcing bar arrangement shown in FIGS. 1 and 2 is applied to the reinforced concrete beam 3 extending along the top and bottom of each of the bearing walls 1.

  In FIG. 1, the reinforced concrete beam 3 has, as a reinforcing bar, an upper bar 12 that is a main bar extending in the beam length direction, a lower bar 13, and a plurality of ribs 14 surrounding the upper bar 12 and the lower bar 13. . At least two upper end bars 12 and lower end bars 13 are provided side by side in the beam width direction.

The upper reinforcement 12 and the lower reinforcement 13, which are the main reinforcements, respectively, are a pair of rebars A ₁ and A ₂ with an enlarged head and a pair of enlarged rebars A ₁ and A _2. The intermediate reinforcing bar B is joined at both ends via the reinforcing bar joint 15. The pair of rebars A ₁ and A ₂ with an enlarged head have an enlarged head Aa at one end. This enlarged diameter head Aa is embedded in the column concrete 4 of the reinforced concrete column 2 adjacent to the bearing wall 1. The fixing length, which is the embedding depth of the enlarged head Aa in the column concrete 4, is appropriately set according to the structure regulations.

As shown in FIG. 1 (C), the upper end muscle 12 and the lower end muscle 13 are the reinforcing bar A ₁ having an enlarged head at one end of the upper end muscle 12 (the left end in FIG. 1), Reinforcing bar A ₁ with an enlarged head at the end (right end in FIG. 1) has the same length and the same cross-sectional dimensions. Further, the rebars A ₁ and A ₂ with enlarged diameter heads on the same end side of the upper end bars 12 and the lower end bars 13 have different lengths and have the same cross-sectional dimensions. The intermediate reinforcing bar B has the same length as the upper reinforcing bar 12 and the lower reinforcing bar 13.
The relationship between the upper reinforcing bars 12 and the lower reinforcing bars 13 with the enlarged head-attached reinforcing bars A ₁ and A ₂ is the same in the width direction position among the plurality of upper reinforcing bars 12 and the lower reinforcing bars 13 arranged in the width direction. It is applied between a certain upper muscle 12 and lower muscle 13. The positions of the reinforcing bar joints 15 are different between the upper end bars 12 and the lower end bars 13 arranged in the width direction. For example per upper muscle 12 any one of a plurality of upper muscle 12 arranged in the width direction, FIG. 1 the shorter diameter headed rebar A ₁ of the (C) at one end, towards the long on the other end When the reinforcing bar A ₂ with an enlarged head is used, the upper reinforcing bar 12 adjacent in the width direction uses the longer enlarged bar with reinforcing head A ₂ in FIG. 1C at one end and is short at the other end. Reinforcing bar A1 with a larger diameter head is used. As in the case of the upper end reinforcement 12, the relationship between the arrangement of the short- and long-diameter rebars A1 and A2 with the enlarged head is also made between the lower end reinforcements 13 adjacent in the width direction.

Position of the enlarged headed rebar A _1, A ₂ and rebar joint 15 for connecting the intermediate reinforcing bar B, as shown in FIG. 7, the upper end muscle 12, the beam center of the L _0/2 range (hatching range) preferably marked with (L ₀ is the total length between the pillars 2, 2 of the beam 3), between the L _0/4 from the pillar 2 for lower muscle 13 to the beam center side starting from the position of RyoNaru D ( It is preferable to carry out in a hatched range. This range is a range determined in the case of gas pressure welding in the above-described general reinforced concrete beam, but this range is also preferable in this embodiment. In addition, since it is the reinforced concrete beam 3 along the load-bearing wall 1 and the load-bearing wall 1 bears stress, the position of the reinforced joint 15 does not necessarily have to be the above position, and may be arbitrarily determined.

Further, in this embodiment, in all the reinforced concrete beams 3 at the positions of the load-bearing walls 1 in the one building described above with reference to FIG. 3, the upper reinforcement 12 and the lower reinforcement 13 are paired as shown in FIG. It is assumed that the rebars A ₁ and A ₂ with a diametrical head and the intermediate rebar B are formed. Further, in the plurality of reinforced concrete beams 3, the rebars A1 and A2 with the enlarged head having mutually corresponding positions, that is, the positional relationships in the length direction, the vertical direction, and the width direction in each beam are the same. The same length, the same cross-sectional dimensions, and the same standards are used.

Reinforcement construction method of the concrete structure beam, in the design method, these enlarged headed rebar A1, A _2, as in FIG. 4, with a plurality of types of enlarged diameter head which is standardized as a standard dimension ones One selected from the reinforcing bars A (A1 to An) is used. For example, selection by rebar makers etc., in advance to prepare the enlarged headed rebar A ₁ to A _n that these standardized in reinforcement design in buildings maker, the standardized rebar A ₁ to A _n To do.

The length of the enlarged diameter rebar A (A ₁ -A _n ) to be standardized and prepared may be at least two, but it is preferable to prepare at least three, for example, several (2-3) Type, or about 2 to 4 types). In the case of a general apartment building, the beam length is mostly 7 to 10 m, so if there are two types, the positions of the rebar joints 15 are different between the upper reinforcement 12 and the lower reinforcement 13 as in the example of FIG. Can be made. If the number of types of length is large, it is easy to respond more appropriately to the building, but the mass productivity of the rebar A with an enlarged head is reduced, and if there are several types, most apartment buildings Since it is not necessary to prepare many kinds more than that, about 2 to 3 kinds are preferable. These types of reinforcing bars A with an enlarged head having a diameter of about 2 to 3 m are prepared with a difference of 0.4 to 1.0 m, for example.
It is preferable to prepare several types of thicknesses and materials of the rebar A with a diameter-enlarged head to be standardized and prepared for each length.

  As shown in FIG. 5, for example, each reinforcing bar A with a diameter-expanded head is formed by forming a conical or circular flange-shaped diameter-expanding head Aa at the end of a reinforcing bar main body Ab. The plastic working of the enlarged diameter head Aa is performed, for example, by subjecting one end of a rebar material manufactured or cut to a predetermined dimension (a dimension slightly longer than the reinforcing bar A with an enlarged diameter head) to high frequency induction heating and compressing in the heated state. It is done by letting. For the reinforcing bar main body Ab, a deformed reinforcing bar having a protrusion Ac on the outer periphery is used. The protrusion Ac is an annular shape, a spiral shape, or a semi-annular shape that is alternately shifted by 180 °.

In addition to this, as shown in FIG. 8 (A), for example, as shown in FIG. 8 (A), the enlarged head Aa of the reinforcing bar A with each enlarged head includes an enlarged head integrated part Aaa that is plastically processed, and the enlarged head. It may consist of a head component plate Aab which is a separate member fixed on the neck side of the integrated portion Aaa. The head component plate Aab has, for example, a square shape, a rectangular shape, a circular shape, or the like on the outer periphery.
Moreover, as shown in FIGS. 8 (B) and 8 (C), the enlarged head Aa of each reinforcing bar A with an enlarged head is composed of a separate member that is fixed to the reinforcing bar main body Ab by attachment. It may be a thing. The enlarged-diameter head Aa, which is a separate member in FIG. 5B, is composed of a disk-shaped fixing plate Aa ′ having a fitting hole a at the center, and friction welding or the like on the outer periphery of the end of the reinforcing bar main body Ab. It is joined by welding or the like. The enlarged-diameter head Aa made of a separate member in FIG. 5C is composed of a screw cylinder portion Aac and an enlarged-diameter portion Aad that is enlarged from one end thereof. The reinforcing bar main body Ab has a spiral protrusion Ac, and the screw cylinder portion Aac is screwed into the outer periphery of the spiral protrusion Ac. Instead of using the protrusion Ac, a male screw part may be provided on the outer periphery of the end of the reinforcing bar main body Ab, and the screw cylinder part Aac may be screwed into the male screw part.

  1, the reinforced joint 15 includes a lap joint in which an overlapping range 20a is provided in the reinforcing bar 20 shown in FIG. 6A, and a gas pressure welded joint that joins the end surfaces 20b of the reinforcing bars 20 as shown in FIG. Or other welded joints (not shown), or special joints (not shown) such as mechanical rebar joints are used. When using a gas pressure welded joint or a welded joint, the ends of the rebar A with the enlarged head and the intermediate rebar B that are joined to each other are slightly cut at the site (for example, around 10 mm) and joined at their cut surfaces. By doing so, the joining is ensured.

According to the reinforcing bar arrangement method of the concrete beam having this structure, since the reinforcing bar A with the enlarged head is used as described above, the amount of the reinforcing bar used is reduced as compared with the case where the reinforcing bar having the bent portion is used. The inner bar arrangement is simplified. Reinforcing bar A with an enlarged head is used, and upper and lower reinforcing bars 12 and 13 which are main reinforcing bars are joined to a pair of enlarged reinforcing bar A (A ₁ , A ₂ ) disposed at both ends of the beam and between them. In order to use the intermediate reinforcing bar B, it is possible to use a standard-sized one, that is, a standardized one, for the reinforcing bar A with an enlarged head. This makes it easy to automate the production line, making it possible to reduce costs and ensure consistent quality through thorough automation, and contribute to shortening the construction period of the building by shortening the delivery time.

  The rebar A with the enlarged head is connected by the intermediate rebar B and the rebar joint 15, but this embodiment is applied to the reinforced concrete beam 3 provided along the load bearing wall 1, and therefore the arrangement of the rebar joint 15. However, there is no problem of touching the structure regulations, and there is no problem in structural strength. That is, in the case of the reinforced concrete beam 3 provided along the bearing wall 1, it does not belong to a pure column beam structure, and the stress acting on the reinforced concrete beam 3 is not greatly different at any position in the beam length direction. Therefore, even if the reinforcing bars are joined at an arbitrary position, there is no problem in strength and reliability. The arrangement of the reinforcing bar joints defined in the structural regulations is a provision for general beams not adjacent to the bearing walls. Conventionally, reinforced concrete beams that are installed along the load-bearing walls are either located at the same position as the general large beam or as a single continuous rebar without joints, but this ensures strength reliability. In terms of this, it is a wasteful overdesign. In addition, it is difficult to improve the quality of long rebars having enlarged heads at both ends due to difficulty in automation. The present invention has been reviewed and optimized for such excessive design, so it is possible to shorten delivery time, ensure quality, and reduce costs through standardization while ensuring strength and reliability. It becomes.

For each upper muscle 12 and lower muscle 13 constituting the main reinforcement, respectively, and enlarged headed rebar A ₁ at the other end of the enlarged diameter head with rebar A ₁ and lower muscle 13 of the upper muscle 12, Since the rebars A ₁ and A ₂ with the enlarged head having the same length and the same cross-sectional dimension and having the same end side of the upper end 12 and the lower end 13 are different in length, 2 By preparing the types of rebars A1 and A2 with an enlarged head, the positions of the joints of the upper and lower reinforcing bars 12 and 13 can be shifted from each other. In addition, by using the above-described two types of rebars A ₁ and A ₂ with an enlarged head, the intermediate rebar B can have the same length for the upper rebar 12 and the lower rebar 13 and is excellent in productivity. It will be.

In this embodiment, the upper reinforcing bars 12 and the lower reinforcing bars 13 as the main reinforcing bars in the plurality of reinforced concrete beams 3 in a single building 11 are the pair of rebars A ₁ and A ₂ with an enlarged head and the intermediate reinforcing bar B. And become. In the plurality of reinforced concrete beams 3, the reinforcing bars A ₁ and A ₂ with enlarged diameter heads corresponding to the same positions are used with the same length and the same cross-sectional dimensions. For this reason, the number of types of reinforcing bars A ₁ and A ₂ with an enlarged head in one building 11 can be reduced. For this reason, productivity improves further.

In the above embodiment, the case where the present invention is applied to the reinforced concrete beam 3 along the load-bearing wall 1 of the same width of one building has been described. However, the present invention has a width as shown in FIG. The present invention can also be applied to a case where there are a plurality of types of load bearing walls 1A and 1B with different reinforced concrete beams 3 along the entire length of the load bearing walls 1A and 1B. In this case, the lengths of the reinforcing bars A ₁ and A 2 with the enlarged heads are obtained with respect to the upper and lower bars 12 and 13 of the reinforced concrete beams 3 provided along the bearing walls 1A and 1B having different widths. May be the same, and only the length of the intermediate reinforcing bar B may be varied.

Further, as shown in FIG. 9B, when one reinforced concrete beam 3 is provided across the bearing walls 1 on both sides where the pillar 2A exists in the middle, the middle pillar 2A portion is shown in FIG. As shown, the upper bar 12 and the lower bar 13 may be provided by passing the intermediate bar B through the column 2A and joining the reinforcing bars A ₁ and A ₂ with the enlarged heads on both sides thereof as shown in FIG.

In addition, although the said embodiment demonstrated about the case where all were applied to the reinforced concrete beam, this invention can also be applied to a steel frame reinforced concrete beam. When applied to a steel-framed reinforced concrete beam, it is also applied when it is provided along a bearing wall.
FIG. 11 shows an example applied to a steel-framed reinforced concrete beam. The column 2 'and the beam 3' are composed of a steel column 21 and a steel beam 23 made of H-shaped steel and the like, and a reinforced concrete portion provided around the column. Is done. The steel column 21 and the steel beam 23 are joined to each other. Reinforcing bars in the reinforced concrete portion of the column 2 'and the beam 3' are the same as those of the column 2 and the beam 3 shown in FIG. In FIG. 11, the shapes of the steel column 21 and the steel beam 23 are illustrated in a simplified manner.

DESCRIPTION OF SYMBOLS 1 ... Bearing wall 2 ... Column 3 ... Reinforced concrete beam 3 '... Steel-framed reinforced concrete beam 10 ... Dwelling space 11 ... Apartment house building 12 ... Top bar 13 ... Bottom bar 14 ... Stirrup 21 ... Steel column 23 ... Steel beam A, A ₁ , A ₂ , A _n ... Reinforcing bar with expanded head Aa ... Expanded head B ... Intermediate reinforcing bar

Claims (1)

Reinforced concrete beam or steel reinforced concrete beam reinforcement is provided along the bearing wall, and each upper bar and lower bar constituting each main bar is a reinforcing bar extending in the beam length direction. A pair of rebars with an enlarged head and intermediate reinforcing bars joined at both ends to the pair of rebars with an enlarged head via rebar joints. The enlarged head is embedded in the concrete of a reinforced concrete column or a steel reinforced concrete column adjacent to the load-bearing wall at one end. A method for laying a concrete beam, characterized by using one selected from reinforcing bars with an enlarged head, which are standardized as 2 to 4 types of standard items.

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