JP2020097853A - Opening reinforcement structure of reinforcement concrete slab, and opening reinforcement - Google Patents
Opening reinforcement structure of reinforcement concrete slab, and opening reinforcement Download PDFInfo
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- 230000002787 reinforcement Effects 0.000 title claims abstract description 157
- 239000004567 concrete Substances 0.000 title abstract description 14
- 230000003014 reinforcing effect Effects 0.000 claims description 282
- 210000003205 muscle Anatomy 0.000 claims description 103
- 239000011150 reinforced concrete Substances 0.000 claims description 85
- 238000009826 distribution Methods 0.000 claims description 74
- 238000005728 strengthening Methods 0.000 claims 1
- 229910000831 Steel Inorganic materials 0.000 description 23
- 239000010959 steel Substances 0.000 description 23
- 238000009434 installation Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 4
- 239000003351 stiffener Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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Abstract
Description
本発明は、鉄筋コンクリートスラブの開口部補強構造及び開口補強筋に関する。 TECHNICAL FIELD The present invention relates to an opening reinforcing structure and an opening reinforcing bar of a reinforced concrete slab.
鉄筋コンクリートスラブは、互いに平行な複数の主筋からなる主筋群と前記主筋に直交する複数の配力筋からなる配力筋群とを有している。また、前記鉄筋コンクリートスラブに開口部が設けられる場合、主に前記鉄筋コンクリートスラブの強度低下やひび割れの発生を防止しようとするため、前記開口部の周囲に開口補強筋が設置される。ここで、前記開口部とは、前記鉄筋コンクリートスラブの上面から下面までを貫通する貫通孔のことをいい、開孔と称される場合もある。また、前記開口部は、通常、スリーブ等を設置した状態でコンクリートが打設され、その後、スリーブ等が取り外されることによって形成される。 The reinforced concrete slab has a main reinforcement group composed of a plurality of main reinforcements parallel to each other and a distribution reinforcement group composed of a plurality of distribution reinforcements orthogonal to the main reinforcements. In addition, when the opening is provided in the reinforced concrete slab, an opening reinforcing bar is installed around the opening mainly in order to prevent a decrease in strength of the reinforced concrete slab and the occurrence of cracks. Here, the opening means a through hole penetrating from the upper surface to the lower surface of the reinforced concrete slab, and may be referred to as an opening. Further, the opening is usually formed by placing concrete with a sleeve or the like installed and then removing the sleeve or the like.
例えば、図１１に示されるように、鉄筋コンクリートスラブＲＣＳに開口部ＯＰが設けられる場合、開口部ＯＰを設けるために切断される主筋５１と同量の開口補強筋（以下「縦補強筋」という）５５が主筋５１に平行に設けられ、開口部ＯＰを設けるために切断される配力筋５２と同量の開口補強筋（以下「横補強筋」という）５６が配力筋５２に平行に設けられ、及び、主筋５１及び配力筋５２に対して傾斜した開口補強筋（以下「斜め補強筋」という）５７が開口部ＯＰの隅角部の近傍であって且つ下端筋と上端筋との間に設けられるのが一般的である。 For example, as shown in FIG. 11, when the opening OP is provided in the reinforced concrete slab RCS, the same amount of the opening reinforcing bar (hereinafter referred to as “vertical reinforcing bar”) as the main bar 51 cut to provide the opening OP. 55 is provided parallel to the main reinforcement 51, and the same amount of opening reinforcement (hereinafter referred to as “lateral reinforcement”) 56 is provided parallel to the distribution reinforcement 52, which is cut to provide the opening OP. And an opening reinforcing bar (hereinafter, referred to as “oblique reinforcing bar”) 57 that is inclined with respect to the main bar 51 and the force distributing bar 52 is near the corner of the opening OP and includes the lower bar and the upper bar. It is generally provided between them.
また、開口部を有する鉄筋コンクリートスラブにおいて、コンクリート打設時の前記開口部近傍でのコンクリートの充填性の低下による強度低下を防止するため、前記開口補強筋を前記斜め補強筋のみで構成することによって前記開口部近傍における鉄筋の密集度を低下させることも提案されている（特許文献１参照）。 Further, in a reinforced concrete slab having an opening, in order to prevent a decrease in strength due to a decrease in the filling property of concrete in the vicinity of the opening at the time of placing concrete, by configuring the opening reinforcing bar only with the diagonal reinforcing bar, It has also been proposed to reduce the density of reinforcing bars near the opening (see Patent Document 1).
前者の場合、前記開口補強筋の数が多く、前記開口補強筋（特に、前記斜め補強筋）の設置作業に手間がかかるという課題がある。また、後者の場合、前者に比べて前記開口補強筋の数は少なくなるが、前記斜め補強筋のそれぞれを設置する必要があるため、依然として前記開口補強筋の設置作業に手間がかかる。 In the case of the former, there is a problem that the number of the opening reinforcing bars is large and it takes time and effort to install the opening reinforcing bars (in particular, the diagonal reinforcing bars). In the latter case, the number of the opening reinforcing bars is smaller than that in the former case, but since it is necessary to install each of the diagonal reinforcing bars, the installation work of the opening reinforcing bars still takes time.
そこで、本発明は、従来に比べて配筋作業性を向上させることのできる鉄筋コンクリートスラブの開口部補強構造及び開口補強筋を提供することを目的とする。 Therefore, it is an object of the present invention to provide an opening reinforcing structure and an opening reinforcing bar of a reinforced concrete slab capable of improving the workability of the bar arrangement as compared with the related art.
本発明の一側面によると、鉄筋コンクリートスラブの開口部補強構造が提供される。この鉄筋コンクリートスラブの開口部補強構造は、鉄筋コンクリートスラブの開口部を囲繞する囲繞補強筋を含む。前記囲繞補強筋は、平面視で八角形状に形成されており、その一対の縦辺部が前記鉄筋コンクリートの主筋に平行となり、かつ、その一対の横辺部が前記鉄筋コンクリートの配力筋に平行となるように設置される。 According to one aspect of the present invention, an opening reinforcement structure for a reinforced concrete slab is provided. The reinforced concrete slab opening reinforcing structure includes a surrounding reinforcing bar surrounding the opening of the reinforced concrete slab. The surrounding reinforcing bars are formed in an octagonal shape in a plan view, and a pair of vertical sides thereof are parallel to the main bars of the reinforced concrete, and the pair of horizontal sides are parallel to the reinforcing bars of the reinforced concrete. Will be installed.
本発明の他の側面によると、鉄筋コンクリートスラブの開口部の周囲に設けられる開口補強筋が提供される。この開口補強筋は、平面視で八角形状に形成されており、前記開口部を囲繞し、一対の縦辺部が前記鉄筋コンクリートスラブの主筋又は前記主筋に平行な鉄筋に取り付けられ、かつ、一対の横辺部が前記鉄筋コンクリートの配力筋又は前記配力筋に平行な鉄筋に取り付けられるように構成されている。 According to another aspect of the present invention, an opening reinforcing bar provided around an opening of a reinforced concrete slab is provided. The opening reinforcing bar is formed in an octagonal shape in a plan view, and surrounds the opening, and a pair of vertical sides is attached to a main bar of the reinforced concrete slab or a reinforcing bar parallel to the main bar, and a pair of vertical sides. The lateral side portion is configured to be attached to a reinforcing bar of the reinforced concrete or a reinforcing bar parallel to the distributing bar.
八角形状に形成された前記囲繞補強筋又は前記開口補強筋の四つの斜辺部は、従来の斜め補強筋としての機能を有する。したがって、本発明によれば、従来の斜め補強筋を省略し又は削減することが可能となる。また、前記囲繞補強筋又は前記開口補強筋は、従来の斜め補強筋に比べて、その配置が容易である。このため、従来に比べて配筋作業性を向上させることができる。 The four oblique sides of the surrounding reinforcing bar or the opening reinforcing bar formed in an octagonal shape have a function as a conventional diagonal reinforcing bar. Therefore, according to the present invention, it is possible to omit or reduce the conventional diagonal reinforcing bar. Further, the surrounding reinforcing bar or the opening reinforcing bar is easier to arrange than the conventional diagonal reinforcing bar. Therefore, it is possible to improve the workability of the bar arrangement as compared with the related art.
本発明は、鉄筋コンクリートスラブの開口部補強構造及び開口補強筋を提供する。本発明による鉄筋コンクリートスラブの開口部補強構造は、鉄筋コンクリートスラブの開口部の周囲に設けられる開口補強筋として、前記開口部を囲繞する八角形状（好ましくは正八角形状）の囲繞補強筋を含む。前記囲繞補強筋は、前記鉄筋コンクリートスラブの下端筋側及び上端筋側のそれぞれに設けられる。もちろん、前記開口部補強構造は、必要に応じて、前記囲繞補強筋に加えて、主筋に平行な縦補強筋及び／又は配力筋に平行な横補強筋も前記開口補強筋として含み得る。 The present invention provides an opening reinforcing structure and an opening reinforcing bar of a reinforced concrete slab. The opening reinforcing structure of a reinforced concrete slab according to the present invention includes an octagonal (preferably regular octagonal) surrounding reinforcing bar surrounding the opening as an opening reinforcing bar provided around the opening of the reinforced concrete slab. The surrounding reinforcing bar is provided on each of the lower end side and the upper end side of the reinforced concrete slab. Of course, the opening reinforcing structure may include, as the opening reinforcing bar, a vertical reinforcing bar parallel to the main bar and/or a lateral reinforcing bar parallel to the force distributing bar, in addition to the surrounding reinforcing bar, if necessary.
前記囲繞補強筋は、例えばあらかじめ所定の長さに切断された鋼棒（異形鋼棒を含む。以下同じ）を八角形状に折り曲げ、その後、前記鋼棒の両端部を突き合わせ溶接などによって接合して形成され得る。そして、前記囲繞補強筋は、前記開口部を囲繞し、その一対の縦辺部が前記鉄筋コンクリートスラブの主筋に平行となり、かつ、その一対の横辺部が前記鉄筋コンクリートスラブの配力筋に平行となるように設置される。具体的には、前記囲繞補強筋は、前記開口部を形成するためのスリーブを囲繞し、前記主筋に平行となり、かつ、前記配力筋に平行となるように配置され、前記鉄筋コンクリートスラブの他の鉄筋に取り付けられる。前記他の鉄筋は、主筋（下端主筋又は上端主筋）、配力筋（下端配力筋又は上端配力筋）、主筋に平行な縦補強筋、配力筋に平行な横補強筋などである。前記囲繞補強筋の前記他の鉄筋への取り付けは、基本的には、鉄筋結束機などを利用して（すなわち、結束によって）行われる。そして、コンクリート打設後に前記スリーブが外されることによって前記開口部が形成される。 The surrounding reinforcing bar is, for example, a steel rod (including a deformed steel rod, the same applies hereinafter) that has been cut into a predetermined length is bent into an octagonal shape, and then both ends of the steel rod are joined by butt welding or the like. Can be formed. Then, the surrounding reinforcing bar surrounds the opening, the pair of vertical sides is parallel to the main bar of the reinforced concrete slab, and the pair of horizontal sides is parallel to the force distribution bar of the reinforced concrete slab. Will be installed. Specifically, the surrounding reinforcing bar surrounds a sleeve for forming the opening, is arranged so as to be parallel to the main bar, and parallel to the force distributing bar, and other than the reinforced concrete slab. Attached to the rebar. The other reinforcing bars are main reinforcing bars (bottom main bars or top main bars), distribution muscles (bottom distribution bars or top distribution bars), vertical reinforcing bars parallel to the main bars, lateral reinforcing bars parallel to the distribution bars. .. The attachment of the reinforcing reinforcing bar to the other reinforcing bar is basically performed by using a reinforcing bar binding machine (that is, by binding). Then, the opening is formed by removing the sleeve after pouring concrete.
前記他の鉄筋に取り付けられた（結束された）前記囲繞補強筋の四つの斜辺部は、従来の斜め補強筋としての機能を有する。したがって、前記囲繞補強筋が前記開口補強筋として用いられることにより、従来の斜め補強筋を省略し又は削減することが可能となる。また、前記囲繞補強筋は、従来の斜め補強筋に比べて、その配置や前記他の鉄筋への取り付け（結束）などが容易である。このため、本発明によれば、補強不十分になることを防止しつつ、従来に比べて前記開口補強筋の設置作業の手間を大幅に軽減することができる。 The four hypotenuses of the surrounding reinforcing bar attached (bound) to the other reinforcing bar function as conventional diagonal reinforcing bars. Therefore, by using the surrounding reinforcing bar as the opening reinforcing bar, it is possible to omit or reduce the conventional diagonal reinforcing bar. Further, the surrounding reinforcing bars are easier to arrange and attach (tie) to the other reinforcing bars, as compared with the conventional diagonal reinforcing bars. Therefore, according to the present invention, it is possible to significantly reduce the time and effort required for the installation work of the opening reinforcing bar as compared with the related art while preventing insufficient reinforcement.
以下、本発明による鉄筋コンクリートスラブの開口部補強構造のいくつかの実施形態について図面を参照して説明する。なお、以下の各実施形態では、前記鉄筋コンクリートスラブの上端筋と下端筋とのうち主に下端筋側の構成について説明する。 Hereinafter, some embodiments of an opening reinforcement structure of a reinforced concrete slab according to the present invention will be described with reference to the drawings. In addition, in each of the following embodiments, a configuration mainly on the lower end reinforcement side of the upper end reinforcement and the lower end reinforcement of the reinforced concrete slab will be described.
［第１実施形態］
図１は、第１実施形態に係る鉄筋コンクリートスラブの開口部補強構造を示す要部概略図であり、コンクリート打設前の下端筋側の構成を示している。鉄筋コンクリートスラブＲＣＳは、互いに平行な複数の主筋１からなる主筋群Ｇ１と、主筋１に直交する複数の配力筋２からなる配力筋群Ｇ２と、を有する。ここでは下端筋側の構成であるので、配力筋群Ｇ２が主筋群Ｇ１の上側に設けられている。
[First Embodiment]
FIG. 1 is a schematic view of a main part showing an opening reinforcing structure of a reinforced concrete slab according to the first embodiment, and shows a configuration of a lower end reinforcement side before concrete placing. The reinforced concrete slab RCS includes a main reinforcing bar group G1 including a plurality of main reinforcing bars 1 that are parallel to each other, and a distributing bar group G2 including a plurality of distributing bars 2 orthogonal to the main reinforcing bar 1. Here, since the configuration is on the lower end muscle side, the force distribution muscle group G2 is provided above the main muscle group G1.
主筋１及び配力筋２には同径の鋼棒が用いられ、主筋１のピッチと配力筋２のピッチとは等しく設定されている。したがって、隣り合う二つの主筋１の内寸（内側の寸法）＝隣り合う二つの配力筋２の内寸であり、隣り合う二つの主筋１の外寸（外側の寸法）＝隣り合う二つの配力筋２の外寸である。具体的には、本実施形態において、主筋１の直径及び配力筋２の直径は約１０ｍｍ（Ｄ１０）であり、主筋１のピッチ及び配力筋２のピッチは２００ｍｍ（＠２００）であり、隣り合う二つの主筋１の内寸（隣り合う二つの配力筋２の内寸）≒１９０ｍｍであり、隣り合う二つの主筋１の外寸（隣り合う二つの配力筋２の外寸）≒２１０ｍｍである。なお、隣り合う二つの主筋１（配力筋２）の内寸を「Ｓａ」とし、隣り合う二つの主筋１（配力筋２）の外寸を「Ｓｂ」とする。 Steel bars having the same diameter are used for the main reinforcement 1 and the distribution reinforcement 2, and the pitch of the main reinforcement 1 and the pitch of the distribution reinforcement 2 are set to be equal. Therefore, the inner dimension (inner dimension) of two adjacent main bars 1 = the inner dimension of two adjacent distribution muscles 2, and the outer dimension (outer dimension) of two adjacent main bars 1 = two adjacent bars It is the outer size of the muscle 2. Specifically, in the present embodiment, the diameter of the main muscle 1 and the diameter of the force distributing muscle 2 are about 10 mm (D10), the pitch of the main muscle 1 and the pitch of the force distributing muscle 2 are 200 mm (@200), Inner size of two adjacent main bars 1 (inner size of two adjacent force distribution bars 2) is approximately 190 mm, and outer size of two adjacent main bars 1 (outer dimension of two adjacent force distribution bars 2) is approximately It is 210 mm. In addition, the inner size of two adjacent main reinforcements 1 (power distribution muscles 2) is "Sa", and the outer size of two adjacent main reinforcements 1 (power distribution muscles 2) is "Sb".
本実施形態において、鉄筋コンクリートスラブＲＣＳには、上面から下面までを貫通する円形の開口部（以下「第１開口部」という）が設けられる。このため、図１に示されるように、第１開口部を形成するためのスリーブ３が設置される。すなわち、スリーブ３が占める領域が第１開口部に相当する。 In the present embodiment, the reinforced concrete slab RCS is provided with a circular opening (hereinafter referred to as “first opening”) that penetrates from the upper surface to the lower surface. Therefore, as shown in FIG. 1, the sleeve 3 for forming the first opening is installed. That is, the area occupied by the sleeve 3 corresponds to the first opening.
スリーブ３の外径（＝第１開口部の径）ｄ１は、隣り合う二つの主筋１の内寸（＝隣り合う二つの配力筋２の内寸）Ｓａよりも小さく設定される。具体的には、本実施形態において、スリーブ３の外径（＝第１開口部の径）ｄ１は１５０ｍｍであり、スリーブ３は隣り合う二つの主筋１と隣り合う二つの配力筋２とによって囲まれる矩形（正方形）領域内に設置されている。つまり、本実施形態において、スリーブ３は主筋１及び配力筋２が切断されることなく設置される。換言すれば、第１開口部は主筋１及び配力筋２が切断されることなく形成される。 The outer diameter (=the diameter of the first opening) d1 of the sleeve 3 is set smaller than the inner dimension Sa of the two adjacent main reinforcements 1 (=the inner dimension of the two adjacent distribution muscles 2). Specifically, in the present embodiment, the outer diameter (=the diameter of the first opening) d1 of the sleeve 3 is 150 mm, and the sleeve 3 is composed of two adjacent main bars 1 and two adjacent distribution bars 2. It is installed in the enclosed rectangular area. That is, in the present embodiment, the sleeve 3 is installed without cutting the main muscle 1 and the distribution muscle 2. In other words, the first opening is formed without cutting the main muscle 1 and the distribution muscle 2.
また、本実施形態においては、前記開口補強筋として第１開口部を囲繞する囲繞補強筋４が用いられる。囲繞補強筋４は、主筋１及び配力筋２よりも大径の鋼棒を用いて形成されている。具体的には、囲繞補強筋４の直径は約１３ｍｍ（Ｄ１３）である。 Further, in the present embodiment, as the opening reinforcing bar, the surrounding reinforcing bar 4 that surrounds the first opening is used. The surrounding reinforcing bar 4 is formed by using a steel rod having a larger diameter than the main bar 1 and the force distributing bar 2. Specifically, the diameter of the reinforcement reinforcement 4 is about 13 mm (D13).
図２は、囲繞補強筋４の平面図である。図２に示されるように、囲繞補強筋４は、平面視で正八角形状に形成されており、一対の縦辺部４ａ、４ｂと、一対の横辺部４ｃ、４ｄと、四つの斜辺部４ｅ〜４ｈと、を有する。また、囲繞補強筋４は、対向する二つの辺部の内寸Ａ１がスリーブ３の外径ｄ１よりも大きく、かつ、対向する二つの辺部の外寸Ｂ１が隣り合う二つの主筋１の外寸（＝隣り合う二つの配力筋２の外寸）Ｓｂとほぼ等しくなるように形成されている。 FIG. 2 is a plan view of the reinforcement reinforcing bar 4. As shown in FIG. 2, the surrounding reinforcing bar 4 is formed in a regular octagonal shape in a plan view, and has a pair of vertical side portions 4a and 4b, a pair of horizontal side portions 4c and 4d, and four oblique side portions. 4e to 4h. In addition, as for the reinforcement reinforcement 4, the inner dimension A1 of the two opposing side portions is larger than the outer diameter d1 of the sleeve 3, and the outer dimension B1 of the two opposing side portions are outside the two main reinforcements 1 adjacent to each other. It is formed so as to be substantially equal to the dimension (=outer dimension of two adjacent distribution muscles 2) Sb.
囲繞補強筋４は、スリーブ３（すなわち、第１開口部）を囲繞し、一対の縦辺部４ａ、４ｂが主筋１に平行となり、かつ、一対の横辺部４ｃ、４ｄが配力筋２に平行となるように配置される。そして、囲繞補強筋４は、一対の縦辺部４ａ、４ｂがスリーブ３（第１開口部）のすぐ外側に位置する二つの主筋１ａ、１ｂに取り付けられ、一対の横辺部４ｃ、４ｄがスリーブ３（第１開口部）のすぐ外側に位置する二つの配力筋２ａ、２ｂに取り付けられる。具体的には、本実施形態において、スリーブ３（第１開口部）のすぐ外側に位置する二つの配力筋２ａ、２ｂが互いの間隔を広げるように変形され、一対の縦辺部４ａ、４ｂは二つの主筋１ａ、１ｂ上に配置されて二つの主筋１ａ、１ｂに結束され、一対の横辺部４ｃ、４ｄは二つの配力筋２ａ、２ｂの内側に配置されて二つの配力筋２ａ、２ｂに結束される。なお、必要に応じて、スリーブ３（第１開口部）のすぐ外側に位置する二つの主筋１ａ、１ｂも互いの間隔を広げるように変形され得る。 The surrounding reinforcing bar 4 surrounds the sleeve 3 (that is, the first opening), the pair of vertical side parts 4 a and 4 b are parallel to the main bar 1, and the pair of lateral side parts 4 c and 4 d are the force distributing bar 2. It is arranged so as to be parallel to. The surrounding reinforcing bar 4 is attached to the two main bars 1a and 1b located just outside the sleeve 3 (first opening) with the pair of vertical side portions 4a and 4b, and the pair of horizontal side portions 4c and 4d. It is attached to the two force distribution muscles 2a and 2b located just outside the sleeve 3 (first opening). Specifically, in the present embodiment, the two force distribution muscles 2a and 2b located immediately outside the sleeve 3 (first opening) are deformed so as to widen the mutual distance, and a pair of vertical side portions 4a, 4b is arranged on the two main bars 1a, 1b and is bound to the two main bars 1a, 1b, and the pair of lateral side portions 4c, 4d is arranged inside the two force distribution bars 2a, 2b to generate two force distributions. It is bound to the muscles 2a and 2b. Note that, if necessary, the two main bars 1a and 1b located immediately outside the sleeve 3 (first opening) can also be deformed so as to widen the distance between them.
なお、上端筋側の場合、主筋群Ｇ１が配力筋群Ｇ２の上側に設けられる。このため、上端筋側の場合、スリーブ３（第１開口部）のすぐ外側に位置する二つの主筋が互いの間隔を広げるように変形され、囲繞補強筋４は、一対の横辺部４ｃ、４ｄがスリーブ３（第１開口部）のすぐ外側に位置する二つの配力筋の上に配置されて当該二つの配力筋に結束され、一対の縦辺部４ａ、４ｂがスリーブ３（第１開口部）のすぐ外側に位置する二つの主筋の内側に配置されて当該二つの主筋に結束される。上端筋の場合も、必要に応じて、スリーブ３（第１開口部）のすぐ外側に位置する二つの配力筋２ａ、２ｂも互いの間隔を広げるように変形され得る。 In the case of the upper end muscle side, the main muscle group G1 is provided above the force distribution muscle group G2. Therefore, in the case of the upper end streak side, the two main stiffeners located immediately outside the sleeve 3 (first opening) are deformed so as to widen the distance between each other, and the surrounding reinforcing stiffener 4 has a pair of lateral side portions 4c, 4d is arranged on the two force distribution muscles located immediately outside the sleeve 3 (first opening) and bound to the two force distribution muscles, and the pair of vertical side portions 4a, 4b forms the sleeve 3 (first (1 opening portion) is arranged inside two main bars located just outside and bound to the two main bars. Also in the case of the upper end streak, if necessary, the two force distribution streaks 2a and 2b located immediately outside the sleeve 3 (first opening) can be deformed so as to widen the mutual space.
図３は、第１実施形態に係る鉄筋コンクリートスラブの開口部補強構造に対応する従来の鉄筋コンクリートスラブの開口部補強構造の一例を示す図である。第１実施形態と共通する要素については同一の符号を用いてその説明は省略する。図３に示されるように、従来の開口部補強構造においては前記開口補強筋として八つの斜め補強筋７が用いられていた。八つの斜め補強筋７は、所定の長さを有し、主筋１及び配力筋２に対して傾斜しており、下端筋と上端筋との間においてスリーブ３（第１開口部）を囲むように設置される。この場合、作業者は、前記開口補強筋（八つの斜め補強筋７）を設けるため、所定の長さに切断された８本の鋼棒のそれぞれを主筋１及び配力筋２に対して傾斜させて適切な位置に配置すると共に、８本の鋼棒のそれぞれを主筋１及び／又は配力筋２に結束する必要がある。このため、前記開口補強筋の設置作業に手間がかかる。 FIG. 3 is a view showing an example of a conventional opening reinforcement structure for a reinforced concrete slab corresponding to the opening reinforcement structure for a reinforced concrete slab according to the first embodiment. The same elements as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. As shown in FIG. 3, in the conventional opening reinforcing structure, eight diagonal reinforcing bars 7 were used as the opening reinforcing bars. The eight diagonal reinforcing bars 7 have a predetermined length, are inclined with respect to the main bar 1 and the force distributing bar 2, and surround the sleeve 3 (first opening) between the lower end bar and the upper end bar. Is installed. In this case, the worker inclines each of the eight steel rods cut into a predetermined length with respect to the main bar 1 and the force distributing bar 2 in order to provide the opening reinforcing bars (eight oblique reinforcing bars 7). It is necessary to bind each of the eight steel rods to the main bar 1 and/or the force distribution bar 2 while arranging them at appropriate positions. Therefore, it takes a lot of time to install the opening reinforcing bar.
これに対し、第１実施形態に係る鉄筋コンクリートスラブの開口部補強構造では、８本の鋼棒を斜め補強筋７として設置することに代えて、下端筋側及び上端筋側のそれぞれにスリーブ３（第１開口部）を囲繞する囲繞補強筋４を設置すればよい。囲繞補強筋４の設置（配置及び結束）は、８本の鋼棒（すなわち、斜め補強筋７）の設置に比べて容易である。したがって、第１実施形態に係る鉄筋コンクリートスラブの開口部補強構造（図１）によれば、従来の鉄筋コンクリートスラブの開口部補強構造（図３）に比べて、開口補強筋の設置作業の手間が大幅に軽減され、配筋作業性が向上する。 On the other hand, in the opening reinforcing structure of the reinforced concrete slab according to the first embodiment, instead of installing eight steel rods as the diagonal reinforcing bars 7, the sleeves 3 ( The surrounding reinforcing bar 4 surrounding the first opening) may be installed. The installation (arrangement and bundling) of the surrounding reinforcing bars 4 is easier than the installation of eight steel bars (that is, the diagonal reinforcing bars 7). Therefore, according to the opening reinforcing structure (FIG. 1) of the reinforced concrete slab according to the first embodiment, compared to the conventional opening reinforcing structure (FIG. 3) of the reinforced concrete slab, the installation work of the opening reinforcing bar is significantly performed. The workability of bar arrangement is improved.
［第２実施形態］
図４は、第２実施形態に係る鉄筋コンクリートスラブの開口部補強構造を示す要部概略図であり、コンクリート打設前の下端筋側の構成を示している。第１実施形態（図１）と共通する要素については同一の符号を用いてその説明は省略する。第１実施形態（図１）と第２実施形態（図４）との主な相違は、次のとおりである。すなわち、第１実施形態においては一つの第１開口部が設けられ又は複数の第１開口部が互いに十分な間隔をあけて設けられる。このため、第１開口部は主筋１及び配力筋２が切断されることなく形成される。これに対し、第２実施形態においては二つの第１開口部が近接して設けられ、二つの第１開口部のうちの一方の第１開口部は主筋１及び配力筋２が切断されることなく形成されるが、他方の第１開口部は配力筋２が切断されることによって形成される。
[Second Embodiment]
FIG. 4 is a schematic view of a main part showing the opening reinforcing structure of the reinforced concrete slab according to the second embodiment, and shows the configuration of the lower end reinforcement side before placing concrete. The same elements as those in the first embodiment (FIG. 1) are designated by the same reference numerals and the description thereof will be omitted. The main differences between the first embodiment (FIG. 1) and the second embodiment (FIG. 4) are as follows. That is, in the first embodiment, one first opening portion is provided or a plurality of first opening portions are provided with a sufficient space therebetween. Therefore, the first opening is formed without cutting the main muscle 1 and the distribution muscle 2. On the other hand, in the second embodiment, the two first openings are provided close to each other, and the main muscle 1 and the force distribution muscle 2 are cut off from the first opening of one of the two first openings. However, the other first opening is formed by cutting the force distribution muscle 2.
本実施形態においては、図４に示されるように、鉄筋コンクリートスラブＲＣＳに二つの第１開口部を形成するため、第１実施形態におけるスリーブ３と同形状の第１、第２スリーブ３Ａ、３Ｂが設置される。前記一方の第１開口部を形成するための第１スリーブ３Ａは、第１実施形態におけるスリーブ３と同様に、隣り合う二つの主筋１と隣り合う二つの配力筋２とによって囲まれる矩形（正方形）領域内に設置される。すなわち、第１スリーブ３Ａは主筋１及び配力筋２が切断されることなく設置される。但し、前記他方の第１開口部を形成するための第２スリーブ３Ｂは配力筋２ｃが切断されることによって設置される（第２スリーブ３Ｂを設置するために配力筋２ｃが切断される）。 In the present embodiment, as shown in FIG. 4, since the two first openings are formed in the reinforced concrete slab RCS, the first and second sleeves 3A and 3B having the same shape as the sleeve 3 in the first embodiment are formed. Is installed. Similar to the sleeve 3 in the first embodiment, the first sleeve 3A for forming the one first opening is a rectangle surrounded by two adjacent main reinforcements 1 and two adjacent distribution muscles 2 ( (Square) area. That is, the first sleeve 3A is installed without cutting the main muscle 1 and the distribution muscle 2. However, the second sleeve 3B for forming the other first opening is installed by cutting the power distribution muscle 2c (the power distribution muscle 2c is cut to install the second sleeve 3B). ).
また、本実施形態においては、前記開口補強筋として、配力筋２に平行な一対の横補強筋６、６と、前記一方の第１開口部を囲繞する第１囲繞補強筋４Ａと、前記他方の第１開口部を囲繞する第２囲繞補強筋４Ｂと、が用いられる。第１、第２囲繞補強筋４Ａ、４Ｂは、第１実施形態における囲繞補強筋４（図２）と同じものである。横補強筋６は、主筋１及び配力筋２よりも大径の鋼棒で形成されており、囲繞補強筋４、４Ａ、４Ｂと同様にその直径は約１３ｍｍ（Ｄ１３）である。 Further, in the present embodiment, as the opening reinforcing bar, a pair of lateral reinforcing bars 6, 6 parallel to the force distributing bar 2, and a first surrounding reinforcing bar 4A surrounding the first opening of the one side, The second surrounding reinforcing bar 4B surrounding the other first opening is used. The first and second surrounding reinforcing bars 4A and 4B are the same as the surrounding reinforcing bars 4 (FIG. 2) in the first embodiment. The lateral reinforcing bar 6 is formed of a steel rod having a larger diameter than the main reinforcing bar 1 and the distributing bar 2, and its diameter is about 13 mm (D13) like the surrounding reinforcing bars 4, 4A and 4B.
一対の横補強筋６、６は、所定の長さを有しており、主筋群Ｇ１の上側において第２スリーブ３Ｂ（前記他方の第１開口部）を挟んで設置される。具体的には、一対の横補強筋６、６は、配力筋２に平行であり、第２スリーブ３Ｂ（前記他方の第１開口部）を挟み、かつ、その内寸が第２囲繞補強筋４Ｂ（＝囲繞補強筋４）の対向する二つの辺部の外寸Ｂ１とほぼ等しくなるように配置され、それぞれが複数の主筋１に取り付けされる（結束される）。 The pair of lateral reinforcing bars 6, 6 has a predetermined length, and is installed above the main bar group G1 with the second sleeve 3B (the other first opening) interposed therebetween. Specifically, the pair of lateral reinforcing bars 6, 6 are parallel to the force distributing muscles 2, sandwich the second sleeve 3B (the other first opening), and the inner size thereof is the second surrounding reinforcement. It is arranged so as to be approximately equal to the outer dimensions B1 of the two opposing side portions of the muscle 4B (=encircling reinforcement muscle 4), and each is attached (bound) to the plurality of main muscles 1.
第１囲繞補強筋４Ａは、第１実施形態における囲繞補強筋４と同様に設置される。すなわち、第１囲繞補強筋４Ａは、第１スリーブ３Ａ（前記一方の第１開口部）を囲繞し、一対の縦辺部４ａ、４ｂが主筋１に平行となり、かつ、一対の横辺部４ｃ、４ｄが配力筋２に平行となるように配置される。そして、第１囲繞補強筋４Ａは、一対の縦辺部４ａ、４ｂが第１スリーブ３Ａ（前記一方の第１開口部）のすぐ外側に位置する二つの主筋１ａ、１ｂに取り付けられ、一対の横辺部４ｃ、４ｄが第１スリーブ３Ａ（前記一方の第１開口部）のすぐ外側に位置する二つの配力筋２ａ、２ｂに取り付けられる。本実施形態においても、第１スリーブ３Ａ（前記一方の第１開口部）のすぐ外側に位置する二つの配力筋２ａ、２ｂが互いの間隔を広げるように変形され、一対の縦辺部４ａ、４ｂは二つの主筋１ａ、１ｂ上に配置されて二つの主筋１ａ、１ｂに結束され、一対の横辺部４ｃ、４ｄは二つの配力筋２ａ、２ｂの内側に配置されて二つの配力筋２ａ、２ｂに結束される。なお、必要に応じて、第１スリーブ３Ａ（前記一方の第１開口部）のすぐ外側に位置する二つの主筋１ａ、１ｂも互いの間隔を広げるように変形され得る。 The first reinforcement reinforcement 4A is installed in the same manner as the reinforcement reinforcement 4 in the first embodiment. That is, the first surrounding reinforcing bar 4A surrounds the first sleeve 3A (the one first opening), the pair of vertical side parts 4a and 4b are parallel to the main bar 1, and the pair of lateral side parts 4c. 4d are arranged so as to be parallel to the force distribution muscle 2. The pair of longitudinal sides 4a, 4b of the first surrounding reinforcement reinforcement 4A are attached to the two main reinforcements 1a, 1b located immediately outside the first sleeve 3A (the one first opening), The lateral side portions 4c and 4d are attached to the two force distribution muscles 2a and 2b located immediately outside the first sleeve 3A (the one first opening portion). Also in the present embodiment, the two force distribution muscles 2a and 2b located immediately outside the first sleeve 3A (the first opening of the one side) are deformed so as to widen the mutual distance, and the pair of vertical side portions 4a. 4b are arranged on the two main bars 1a, 1b and bound to the two main bars 1a, 1b, and the pair of lateral sides 4c, 4d are arranged inside the two force distribution bars 2a, 2b. It is bound to the force muscles 2a and 2b. If necessary, the two main bars 1a and 1b located immediately outside the first sleeve 3A (the one first opening) may be deformed so as to widen the mutual distance.
第２囲繞補強筋４Ｂは、第２スリーブ３Ｂ（前記他方の第１開口部）を囲繞し、一対の縦辺部４ａ、４ｂが主筋１に平行となり、かつ、一対の横辺部４ｃ、４ｄが配力筋２に平行となるように配置される。そして、第２囲繞補強筋４Ｂは、一対の縦辺部４ａ、４ｂが第２スリーブ３Ｂ（前記他方の第１開口部）のすぐ外側に位置する二つの主筋１ａ、１ｂに取り付けられ、一対の横辺部４ｃ、４ｄが一対の横補強筋６、６に取り付けられる。具体的には、一対の縦辺部４ａ、４ｂは二つの主筋１ａ、１ｂ上に配置されて二つの主筋１ａ、１ｂに結束され、一対の横辺部４ｃ、４ｄは一対の横補強筋６、６の内側に配置されて一対の横補強筋６、６に結束される。なお、必要に応じて、第２スリーブ３Ｂ（前記他方の第１開口部）のすぐ外側に位置する二つの主筋１ａ、１ｂが互いの間隔を広げるように変形され得る。 The second surrounding reinforcing bar 4B surrounds the second sleeve 3B (the other first opening), the pair of vertical sides 4a, 4b are parallel to the main bar 1, and the pair of lateral sides 4c, 4d. Are arranged so as to be parallel to the force distribution muscles 2. Then, the second surrounding reinforcing bar 4B is attached to the two main bars 1a, 1b located at the outer sides of the second sleeve 3B (the other first opening) with the pair of vertical sides 4a, 4b. The lateral sides 4c and 4d are attached to the pair of lateral reinforcing bars 6 and 6. Specifically, the pair of vertical side portions 4a and 4b are arranged on the two main reinforcements 1a and 1b and bound to the two main reinforcements 1a and 1b, and the pair of horizontal side portions 4c and 4d are paired with the horizontal reinforcement reinforcements 6. , 6 and are bound to a pair of lateral reinforcing bars 6, 6. Note that, if necessary, the two main bars 1a and 1b located immediately outside the second sleeve 3B (the other first opening) can be deformed so as to widen the distance between them.
なお、上端筋側の場合には、例えば次のように構成される。一対の横補強筋６、６は、配力筋２に平行であり、第２スリーブ３Ｂ（前記他方の第１開口部）を挟み、かつ、その外寸が第２囲繞補強筋４Ｂの対向する二つの辺部の外寸Ｂ１とほぼ等しくなるように配置され、それぞれが主筋１の配筋時に複数の主筋１と結束される。第１スリーブ３Ａ（前記一方の第１開口部）のすぐ外側に配置される二つの主筋が互いの間隔を広げるように変形され、第１囲繞補強筋４Ａは、一対の横辺部４ｃ、４ｄが第１スリーブ３Ａ（前記一方の第１開口部）のすぐ外側に位置する二つの配力筋の上に配置されて当該二つの配力筋に結束され、一対の縦辺部４ａ、４ｂが第１スリーブ３Ａ（前記一方の第１開口部）のすぐ外側に配置される二つの主筋に結束される。第２囲繞補強筋４Ｂは、一対の横辺部４ｃ、４ｄが一対の横補強筋６、６上に配置されて一対の横補強筋６、６に結束され、一対の縦辺部４ａ、４ｂが第２スリーブ３Ｂ（前記他方の第１開口部）のすぐ外側に配置される二つの主筋に結束される。 In addition, in the case of the upper end streak side, for example, it is configured as follows. The pair of lateral reinforcing bars 6, 6 are parallel to the force distributing muscles 2, sandwich the second sleeve 3B (the other first opening), and the outer dimensions thereof face the second surrounding reinforcing bars 4B. It is arranged so as to be approximately equal to the outer dimensions B1 of the two sides, and each of them is bound to the plurality of main bars 1 when the main bars 1 are arranged. The two main reinforcements arranged immediately outside the first sleeve 3A (the first opening on the one side) are deformed so as to widen the distance between them, and the first surrounding reinforcement reinforcement 4A has a pair of lateral sides 4c, 4d. Is arranged on the two force distribution muscles located immediately outside the first sleeve 3A (the first opening of the one side) and is bound to the two force distribution muscles. It is tied to two main bars arranged immediately outside the first sleeve 3A (the one first opening). In the second surrounding reinforcing bar 4B, the pair of lateral sides 4c, 4d are arranged on the pair of lateral reinforcing bars 6, 6 and bound to the pair of lateral reinforcing bars 6, 6 to form a pair of vertical sides 4a, 4b. Are bound to two main bars arranged immediately outside the second sleeve 3B (the other first opening).
図５は、第２実施形態に係る鉄筋コンクリートスラブの開口部補強構造に対応する従来の鉄筋コンクリートスラブの開口部補強構造の一例を示す図である。第２実施形態と共通する要素については同一の符号を用いてその説明は省略する。図５に示されるように、従来の開口補強構造においては、前記開口補強筋として、一対の横補強筋６、６と、八つの第１斜め補強筋８Ａと、四つの第２斜め補強筋８Ｂと、が用いられていた。八つの第１斜め補強筋８Ａは、所定の長さを有し、主筋１及び配力筋２に対して傾斜しており、下端筋と上端筋との間において第１スリーブ３Ａ（前記一方の第１開口部）及び第２スリーブ３Ｂ（前記他方の第１開口部）を囲むように設置される。四つの第２斜め補強筋８Ｂは、第１斜め補強筋８Ａよりも長い所定の長さを有し、主筋１及び配力筋２に対して傾斜しており、下端筋と上端筋との間において第１スリーブ３Ａ（前記一方の第１開口部）と第２スリーブ３Ｂ（前記他方の第１開口部）との間に設置される。この場合、作業者は、八つの第１斜め補強筋８Ａ及び四つの第２斜め補強筋８Ｂを設けるため、所定の長さに切断された１２本の鋼棒のそれぞれを主筋１及び配力筋２に対して傾斜させて適切な位置に配置すると共に、１２本の鋼棒のそれぞれを主筋１及び／又は配力筋２に結束する必要がある。このため、前記開口補強筋の設置作業に手間がかかる。 FIG. 5: is a figure which shows an example of the conventional opening reinforcement structure of a reinforced concrete slab corresponding to the opening reinforcement structure of the reinforced concrete slab which concerns on 2nd Embodiment. The same elements as those in the second embodiment are designated by the same reference numerals, and the description thereof will be omitted. As shown in FIG. 5, in the conventional opening reinforcing structure, as the opening reinforcing bars, a pair of lateral reinforcing bars 6, 6, eight first diagonal reinforcing bars 8A, and four second diagonal reinforcing bars 8B. And were used. The eight first diagonal reinforcing bars 8A have a predetermined length, are inclined with respect to the main bar 1 and the force distributing bar 2, and are located between the lower end bar and the upper end bar, and the first sleeve 3A (the one of the one It is installed so as to surround the first opening) and the second sleeve 3B (the other first opening). The four second diagonal reinforcing bars 8B have a predetermined length longer than that of the first diagonal reinforcing bars 8A, are inclined with respect to the main muscle 1 and the force distributing muscles 2, and are located between the lower end muscles and the upper end muscles. Is installed between the first sleeve 3A (the one first opening) and the second sleeve 3B (the other first opening). In this case, in order to provide the eight first diagonal reinforcing bars 8A and the four second diagonal reinforcing bars 8B, the worker uses each of the twelve steel rods cut into a predetermined length as the main bar 1 and the distribution bar. It is necessary to incline each of the 12 steel rods to the main bar 1 and/or the force distributing bar 2 while arranging them at an appropriate position by inclining with respect to 2. Therefore, it takes a lot of time to install the opening reinforcing bar.
これに対し、第２実施形態に係る鉄筋コンクリートスラブの開口部補強構造では、１２個の鋼棒を第１、第２斜め補強筋８Ａ、８Ｂとして設置することに代えて、下端筋側及び上端筋側のそれぞれに第１スリーブ３Ａ（前記一方の第１開口部）を囲繞する第１囲繞補強筋４Ａ及び第２スリーブ３Ｂ（前記他方の第１開口部）を囲繞する第２囲繞補強筋４Ｂを設置すればよい。第１、第２囲繞補強筋４Ａ、４Ｂの設置は、１２個の鋼棒（すなわち、第１、第２斜め補強筋８Ａ、８Ｂ）の設置に比べて容易である。したがって、第２実施形態に係る鉄筋コンクリートスラブの開口部補強構造（図４）によれば、従来の鉄筋コンクリートスラブの開口部補強構造（図５）に比べて、開口補強筋の設置作業の手間が大幅に軽減され、配筋作業性が向上する。 On the other hand, in the opening reinforcing structure of the reinforced concrete slab according to the second embodiment, instead of installing 12 steel bars as the first and second diagonal reinforcing bars 8A and 8B, the lower reinforcing bar side and the upper reinforcing bar are provided. Each of the sides is provided with a first surrounding reinforcing bar 4A surrounding the first sleeve 3A (the one first opening) and a second surrounding reinforcing bar 4B surrounding the second sleeve 3B (the other first opening). Just install it. Installation of the first and second surrounding reinforcing bars 4A and 4B is easier than installation of twelve steel bars (that is, the first and second diagonal reinforcing bars 8A and 8B). Therefore, according to the opening reinforcing structure (FIG. 4) of the reinforced concrete slab according to the second embodiment, compared to the conventional opening reinforcing structure (FIG. 5) of the reinforced concrete slab, the work of installing the opening reinforcing bar is significantly performed. The workability of bar arrangement is improved.
なお、第２実施形態に係る鉄筋コンクリートスラブの開口部補強構造において、前記他方の第１開口部は配力筋２が切断されることよって形成される。しかし、これに限られるものではない。前記他方の第１開口部は主筋１が切断されることによって形成されてもよい。この場合においては、一対の横補強筋６、６に代えて、主筋１に平行な一対の縦補強筋が用いられる。前記一対の縦補強筋は、所定の長さを有し、配力筋群Ｇ２の下側において第２スリーブ３Ｂ（前記他方の第１開口部）を挟んで設置される。そして、第２囲繞補強筋４Ｂは、第２スリーブ３Ｂ（前記他方の第１開口部）を囲繞し、一対の縦辺部４ａ、４ｂが主筋１に平行となり、かつ、一対の横辺部４ｃ、４ｄが配力筋２に平行となるように配置され、一対の縦辺部４ａ、４ｂが前記一対の縦補強筋に取り付けられ、一対の横辺部４ｃ、４ｄが第２スリーブ３Ｂ（前記他方の第１開口部）のすぐ外側に位置する二つの配力筋に取り付けられる。 In the reinforced concrete slab opening reinforcing structure according to the second embodiment, the other first opening is formed by cutting the force distribution bar 2. However, it is not limited to this. The other first opening may be formed by cutting the main bar 1. In this case, a pair of vertical reinforcing bars parallel to the main bar 1 is used instead of the pair of horizontal reinforcing bars 6, 6. The pair of vertical reinforcing bars has a predetermined length, and is installed below the force distributing muscle group G2 with the second sleeve 3B (the other first opening) interposed therebetween. The second surrounding reinforcing bar 4B surrounds the second sleeve 3B (the other first opening), the pair of vertical sides 4a and 4b are parallel to the main bar 1, and the pair of lateral sides 4c. 4d are arranged so as to be parallel to the force distributing muscles 2, the pair of vertical side portions 4a, 4b are attached to the pair of vertical reinforcing bars, and the pair of horizontal side portions 4c, 4d are arranged in the second sleeve 3B (the above-mentioned It is attached to two distribution muscles located just outside the other first opening).
また、第２実施形態に係る鉄筋コンクリートスラブの開口補強構造において、前記一方の第１開口部又は前記他方の第１開口部に近接する追加の第１開口部がさらに設けられてもよい。この場合、前記追加の第１開口部を形成されるために主筋１及び配力筋２のいずれが切断されるかに応じて、前記追加の第１開口部を囲繞する囲繞補強筋と、配力筋２に平行であり且つ前記追加の第１開口部を挟んで配置される一対の横補強筋又は主筋１に平行であり且つ前記追加の第１開口部を挟んで配置される一対の横補強筋と、が前記開口補強筋として適宜追加される。 Further, in the opening reinforcing structure for a reinforced concrete slab according to the second embodiment, an additional first opening portion may be further provided near the one first opening portion or the other first opening portion. In this case, depending on which of the main bar 1 and the force distribution bar 2 is cut to form the additional first opening, the surrounding reinforcing bar surrounding the additional first opening is arranged. A pair of horizontal reinforcements parallel to the force muscles 2 and arranged to sandwich the additional first opening or a pair of horizontal reinforcements parallel to the main reinforcement 1 and arranged to sandwich the additional first opening. Reinforcing bars are appropriately added as the opening reinforcing bars.
［第３実施形態］
図６は、第３実施形態に係る鉄筋コンクリートスラブの開口部補強構造を示す要部概略図であり、コンクリート打設前の下端筋側の構成を示している。第１実施形態（図１）と共通する要素については同一の符号を用いてその説明は省略する。第１実施形態（図１）と第３実施形態（図６）との主な相違は、次のとおりである。すなわち、第１実施形態において、鉄筋コンクリートスラブＲＣＳには主筋１及び配力筋２が切断されることなく形成される第１開口部が設けられる。これに対し、第３実施形態において、鉄筋コンクリートスラブＲＣＳには第１開口部よりも開口面積の大きい開口部（以下「第２開口部」という）が設けられ、第２開口部は主筋１及び配力筋が切断されることによって形成される。
[Third Embodiment]
FIG. 6 is a schematic view of a main part of a reinforcement structure for an opening portion of a reinforced concrete slab according to the third embodiment, showing a configuration of a lower end reinforcement side before placing concrete. The same elements as those in the first embodiment (FIG. 1) are designated by the same reference numerals and the description thereof will be omitted. The main differences between the first embodiment (FIG. 1) and the third embodiment (FIG. 6) are as follows. That is, in the first embodiment, the reinforced concrete slab RCS is provided with the first opening formed without cutting the main bar 1 and the force distribution bar 2. On the other hand, in the third embodiment, the reinforced concrete slab RCS is provided with an opening portion (hereinafter, referred to as “second opening portion”) having an opening area larger than that of the first opening portion, and the second opening portion includes It is formed by cutting the force muscle.
本実施形態においては、図６に示されるように、鉄筋コンクリートスラブＲＣＳに第２開口部を形成するためのスリーブ１３が設置される。すなわち、スリーブ１３が占める領域が第２開口部に相当する。 In the present embodiment, as shown in FIG. 6, the sleeve 13 for forming the second opening is installed in the reinforced concrete slab RCS. That is, the area occupied by the sleeve 13 corresponds to the second opening.
スリーブ１３の外径（すなわち、第２開口部の径）ｄ２は、隣り合う二つの主筋１の外寸（＝隣り合う二つの配力筋２の外寸）Ｓｂよりも大きく設定される。具体的には、本実施形態において、スリーブ１３の外径（＝第２開口部の径）ｄ２は３００ｍｍであり、スリーブ１３を設置するために、主筋１ａ、１ｂ及び配力筋２ａ、２ｂが切断される。つまり、本実施形態において、スリーブ１３は主筋１ａ、１ｂ及び配力筋２ａ、２ｂが切断されることによって設置される。換言すれば、第２開口部は主筋１ａ、１ｂ及び配力筋２ａ、２ｂが切断されることよって形成される。 The outer diameter of the sleeve 13 (that is, the diameter of the second opening) d2 is set to be larger than the outer dimension of two adjacent main bars 1 (=the outer dimension of two adjacent force distribution bars 2) Sb. Specifically, in the present embodiment, the outer diameter (=the diameter of the second opening) d2 of the sleeve 13 is 300 mm, and in order to install the sleeve 13, the main muscles 1a and 1b and the force distribution muscles 2a and 2b are Be disconnected. That is, in the present embodiment, the sleeve 13 is installed by cutting the main muscles 1a and 1b and the power distribution muscles 2a and 2b. In other words, the second opening is formed by cutting the main muscles 1a, 1b and the power distribution muscles 2a, 2b.
また、本実施形態においては、前記開口補強筋として、主筋１に平行な一対の縦補強筋１５、１５と、配力筋２に平行な一対の横補強筋１６、１６と、第２開口部を囲繞する囲繞補強筋１４と、が用いられる。囲繞補強筋１４、縦補強筋１５及び横補強筋１６は、主筋１及び配力筋２よりも大径の鋼棒で形成されている。具体的には、囲繞補強筋１４、縦補強筋１５及び横補強筋１６の直径は約１３ｍｍ（Ｄ１３）である。 Further, in the present embodiment, as the opening reinforcing bar, a pair of vertical reinforcing bars 15 and 15 parallel to the main bar 1, a pair of lateral reinforcing bars 16 and 16 parallel to the force distributing bar 2, and the second opening Surrounding reinforcement bars 14 that surround the are used. The surrounding reinforcing bar 14, the vertical reinforcing bar 15 and the horizontal reinforcing bar 16 are formed of a steel rod having a larger diameter than the main bar 1 and the force distributing bar 2. Specifically, the diameters of the surrounding reinforcing bar 14, the vertical reinforcing bar 15, and the horizontal reinforcing bar 16 are about 13 mm (D13).
図７は、囲繞補強筋１４の平面図である。図７に示されるように、囲繞補強筋１４は、第１実施形態における囲繞補強筋４と同様、平面視で正八角形状に形成されており、一対の縦辺部１４ａ、１４ｂと、一対の横辺部１４ｃ、１４ｄと、四つの斜辺部１４ｅ〜１４ｈと、を有する。また、囲繞補強筋１４は、対向する二つの辺部の内寸Ａ２がスリーブ１３の外径ｄ２よりも大きく形成されている。なお、対向する二つの辺部の外寸は「Ｂ２」とする。 FIG. 7 is a plan view of the surrounding reinforcing bar 14. As shown in FIG. 7, the reinforcement reinforcement 14 is formed in a regular octagonal shape in plan view like the reinforcement reinforcement 4 in the first embodiment, and has a pair of vertical side portions 14a and 14b and a pair of vertical sides. It has side portions 14c and 14d and four oblique side portions 14e to 14h. The surrounding reinforcing bar 14 is formed such that the inner dimension A2 of the two opposing side portions is larger than the outer diameter d2 of the sleeve 13. The outer dimensions of the two opposite side portions are “B2”.
一対の縦補強筋１５、１５は、所定の長さを有しており、配力筋群Ｇ２の下側においてスリーブ１３（第２開口部）を挟んで設置される。具体的には、一対の縦補強筋１５、１５は、主筋１に平行であり、スリーブ１３（第２開口部）を挟み、かつ、その外寸が囲繞補強筋１４の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが配力筋２の配筋時に複数の配力筋２と結束される。 The pair of vertical reinforcing bars 15 and 15 have a predetermined length, and are installed below the distribution muscle group G2 with the sleeve 13 (second opening) interposed therebetween. Specifically, the pair of vertical reinforcing bars 15 and 15 is parallel to the main bar 1, sandwiches the sleeve 13 (second opening), and the outer dimensions of the pair of vertical reinforcing bars 15 are opposite to each other. Are arranged so as to be substantially equal to the outer dimension B2 of the above, and each of them is bound to a plurality of force distributing muscles 2 when the force distributing muscles 2 are arranged.
一対の横補強筋１６、１６は、所定の長さを有しており、主筋群Ｇ１の上側においてスリーブ１３（第２開口部）を挟んで設置される。具体的には、一対の横補強筋１６、１６は、配力筋２に平行であり、スリーブ１３（第２開口部）を挟み、かつ、その内寸が囲繞補強筋１４の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが複数の主筋１に取り付けられる（結束される）。 The pair of lateral reinforcing bars 16 and 16 have a predetermined length, and are installed above the main bar group G1 with the sleeve 13 (second opening) interposed therebetween. Specifically, the pair of lateral reinforcing bars 16 and 16 are parallel to the force distributing muscles 2 and sandwich the sleeve 13 (second opening), and the inner dimensions of the pair of lateral reinforcing bars 16 and 16 are opposite to each other. It is arranged so as to be approximately equal to the outer dimension B2 of the side portion, and each is attached (bound) to the plurality of main bars 1.
囲繞補強筋１４は、スリーブ１３（第２開口部）を囲繞し、一対の縦辺部１４ａ、１４ｂが主筋１に平行となり、かつ、一対の横辺部１４ｃ、１４ｄが配力筋２に平行となるように配置され、一対の縦辺部１４ａ、１４ｂが一対の縦補強筋１５、１５に取り付けられ、一対の横辺部１４ｃ、１４ｄが一対の横補強筋１６、１６に取り付けられる。具体的には、一対の縦辺部１４ａ、１４ｂは一対の縦補強筋１５、１５上に配置されて一対の縦補強筋１５、１５に結束され、一対の横辺部１４ｃ、１４ｄは一対の横補強筋１６、１６の内側に配置されて一対の横補強筋１６、１６に結束される。 The surrounding reinforcing bar 14 surrounds the sleeve 13 (second opening), the pair of vertical side parts 14 a and 14 b are parallel to the main bar 1, and the pair of lateral side parts 14 c and 14 d are parallel to the force distributing bar 2. The pair of vertical side portions 14a and 14b are attached to the pair of vertical reinforcing bars 15 and 15, and the pair of horizontal side portions 14c and 14d are attached to the pair of horizontal reinforcing bars 16 and 16. Specifically, the pair of vertical side portions 14a and 14b are arranged on the pair of vertical reinforcing bars 15 and 15 and bound to the pair of vertical reinforcing bars 15 and 15, and the pair of horizontal side portions 14c and 14d are paired. It is arranged inside the lateral reinforcing bars 16, 16 and is bound to the pair of lateral reinforcing bars 16, 16.
なお、上端筋の場合には、例えば次のように構成される。一対の縦補強筋１５、１５は、主筋１に平行であり、スリーブ１３（第２開口部）を挟み、かつ、その内寸が囲繞補強筋１４の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが複数の配力筋２に取り付けられる（結束される）。一対の横補強筋１６、１６は、配力筋２に平行であり、スリーブ１３（第２開口部）を挟み、かつ、その外寸が囲繞補強筋１４の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが主筋１の配筋時に複数の主筋１と結束される。囲繞補強筋１４は、一対の横辺部１４ｃ、１４ｄが一対の横補強筋１６、１６上に配置されて一対の横補強筋１６、１６に結束され、一対の縦辺部１４ａ、１４ｂが一対の縦補強筋１５、１５の内側に配置されて一対の縦補強筋１５、１５に結束される。 In addition, in the case of the upper end streak, for example, it is configured as follows. The pair of vertical reinforcing bars 15 and 15 are parallel to the main bar 1 and sandwich the sleeve 13 (second opening), and the inner dimensions thereof are the outer dimensions B2 of two opposite sides of the surrounding reinforcing bar 14. It arrange|positions so that it may become substantially equal, and each is attached to the some distribution muscle 2, (it is united). The pair of lateral reinforcing bars 16, 16 are parallel to the force distributing muscles 2, sandwich the sleeve 13 (second opening), and the outer dimensions of the pair of lateral reinforcing bars 16, 16 are the outer dimensions of the two opposite sides of the surrounding reinforcing bar 14. It is arranged so as to be almost equal to B2, and each is bound to a plurality of main muscles 1 when the main muscles 1 are arranged. The surrounding reinforcement 14 has a pair of horizontal sides 14c and 14d arranged on the pair of horizontal reinforcements 16 and 16 and bound to the pair of horizontal reinforcements 16 and 16 to form a pair of vertical sides 14a and 14b. The vertical reinforcing bars 15 and 15 are arranged inside and are bound to the pair of vertical reinforcing bars 15 and 15.
図８は、第３実施形態に係る鉄筋コンクリートスラブの開口部補強構造に対応する従来の鉄筋コンクリートスラブの開口部補強構造の一例を示す図である。第３実施形態と共通する要素については同一の符号を用いてその説明は省略する。図８に示されるように、従来の開口部補強構造においては、前記開口補強筋として、一対の縦補強筋１５、１５と、一対の横補強筋１６、１６と、八つの斜め補強筋１７と、が用いられていた。八つの斜め補強筋１７は、所定の長さを有し、主筋１及び配力筋２に対して傾斜しており、下端筋と上端筋との間においてスリーブ１３（第２開口部）を囲むように設置される。したがって、作業者は、八つの補強筋１７を設けるために、所定の長さに切断された８本の鋼棒のそれぞれを主筋１及び配力筋２に対して傾斜させて適切な位置に配置すると共に、８本の鋼棒のそれぞれを主筋１、配力筋２、縦補強筋１５及び／又は横補強筋１６に結束する必要がある。このため、前記開口補強筋の設置作業に手間がかかる。 FIG. 8: is a figure which shows an example of the opening reinforcement structure of the conventional reinforced concrete slab corresponding to the opening reinforcement structure of the reinforced concrete slab which concerns on 3rd Embodiment. The same elements as those in the third embodiment are designated by the same reference numerals and the description thereof will be omitted. As shown in FIG. 8, in the conventional opening reinforcing structure, a pair of vertical reinforcing bars 15, 15, a pair of horizontal reinforcing bars 16, 16 and eight diagonal reinforcing bars 17 are provided as the opening reinforcing bars. , Were used. The eight diagonal reinforcing bars 17 have a predetermined length, are inclined with respect to the main bar 1 and the force distributing bar 2, and surround the sleeve 13 (second opening) between the lower end bar and the upper end bar. Is installed. Therefore, in order to provide the eight reinforcing bars 17, the worker inclines each of the eight steel rods cut into a predetermined length with respect to the main bar 1 and the force distributing bar 2 and arranges them at appropriate positions. At the same time, it is necessary to bind each of the eight steel rods to the main reinforcement 1, the distribution reinforcement 2, the vertical reinforcement reinforcement 15, and/or the horizontal reinforcement reinforcement 16. Therefore, it takes a lot of time to install the opening reinforcing bar.
これに対し、第３実施形態に係る鉄筋コンクリートスラブの開口部補強構造では、８本の鋼棒を斜め補強筋１７として設置することに代えて、下端筋側及び上端筋側のそれぞれにスリーブ１３（前記第２開口部）を囲繞する囲繞補強筋１４を設置すればよい。したがって、第３実施形態に係る鉄筋コンクリートスラブの開口部補強構造（図６）によれば、従来の鉄筋コンクリートスラブの開口部補強構造（図８）に比べて、開口補強筋の設置作業の手間が大幅に軽減され、配筋作業性が向上する。 On the other hand, in the opening reinforcing structure for the reinforced concrete slab according to the third embodiment, instead of installing eight steel rods as the diagonal reinforcing bars 17, the sleeves 13 ( The surrounding reinforcing bar 14 may be installed to surround the second opening). Therefore, according to the opening reinforcing structure (FIG. 6) of the reinforced concrete slab according to the third embodiment, compared to the conventional opening reinforcing structure (FIG. 8) of the reinforced concrete slab, the work of installing the opening reinforcing bar is significantly performed. The workability of bar arrangement is improved.
［第４実施形態］
図９は、第４実施形態に係る鉄筋コンクリートスラブの開口部補強構造を示す要部概略図であり、コンクリート打設前の下端筋側の構成を示している。第３実施形態（図６）と共通する要素については同一の符号を用いてその説明は省略する。第３実施形態（図６）と第４実施形態（図９）との主な相違は、次のとおりである。すなわち、第３実施形態においては一つの第２開口部が設けられ又は複数の第２開口部が互いに十分な間隔を開けて設けられる。これに対し、第４実施形態においては二つの第２開口部が近接して設けられる。
[Fourth Embodiment]
FIG. 9 is a schematic view of a main part showing the opening reinforcing structure of the reinforced concrete slab according to the fourth embodiment, and shows the configuration of the lower end reinforcement side before placing concrete. Elements common to those in the third embodiment (FIG. 6) will be assigned the same reference numerals and explanations thereof will be omitted. The main differences between the third embodiment (FIG. 6) and the fourth embodiment (FIG. 9) are as follows. That is, in the third embodiment, one second opening is provided or a plurality of second openings are provided with a sufficient space therebetween. On the other hand, in the fourth embodiment, two second openings are provided close to each other.
本実施形態においては、図９に示されるように、鉄筋コンクリートスラブＲＣＳに二つの第２開口部を形成するため、第３実施形態におけるスリーブ１３と同形状の第１、第２スリーブ１３Ａ、１３Ｂが設置される。二つの第２開口部のうちの一方の第２開口部を形成するための第１スリーブ１３Ａは、第３実施形態におけるスリーブ１３と同様、主筋１ａ、１ｂ及び配力筋２ａ、２ｂが切断されることによって設置され、他方の第２開口部を形成するための第２スリーブ１３Ｂは、主筋１ａ、１ｂ及び配力筋２ｃ、２ｄが切断されることによって設置される。換言すれば、前記一方の第２開口部は主筋１ａ、１ｂ及び配力筋２ａ、２ｂが切断されることよって形成され、前記他方の第２開口部は主筋１ａ、１ｂ及び配力筋２ｃ、２ｄが切断されることによって形成される。 In the present embodiment, as shown in FIG. 9, since the two second openings are formed in the reinforced concrete slab RCS, the first and second sleeves 13A and 13B having the same shape as the sleeve 13 in the third embodiment are formed. Is installed. The first sleeve 13A for forming one of the two second openings is cut with the main muscles 1a, 1b and the force distribution muscles 2a, 2b, like the sleeve 13 in the third embodiment. The second sleeve 13B that is installed by forming the other second opening is installed by cutting the main muscles 1a and 1b and the force distribution muscles 2c and 2d. In other words, the one second opening is formed by cutting the main muscles 1a, 1b and the power distribution muscles 2a, 2b, and the other second opening is formed by the main muscles 1a, 1b and the power distribution muscles 2c, It is formed by cutting 2d.
また、本実施形態においては、前記開口補強筋として、主筋１に平行な一対の縦補強筋２５、２５と、配力筋２に平行な一対の第１横補強筋１６Ａ、１６Ａと、配力筋２に平行な一対の第２横補強筋１６Ｂ、１６Ｂと、前記一方の第２開口部を囲繞する第１囲繞補強筋１４Ａと、前記他方の第２開口部を囲繞する第２囲繞補強筋１４Ｂと、が用いられる。第１、第２囲繞補強筋１４Ａ、１４Ｂは、第３実施形態における囲繞補強筋１４と同じものであり、第１、第２横補強筋１６Ａ、１６Ｂは、第３実施形態における横補強筋１６と同じものである。縦補強筋２５は、第３実施形態における縦補強筋１５よりも長く形成されている。 Further, in the present embodiment, as the opening reinforcing bar, a pair of vertical reinforcing bars 25, 25 parallel to the main bar 1, a pair of first lateral reinforcing bars 16A, 16A parallel to the force distributing bar 2, A pair of second lateral reinforcing bars 16B and 16B parallel to the muscle 2, a first surrounding reinforcing bar 14A surrounding the one second opening, and a second surrounding reinforcing bar surrounding the other second opening. 14B and are used. The first and second surrounding reinforcements 14A and 14B are the same as the surrounding reinforcements 14 in the third embodiment, and the first and second lateral reinforcements 16A and 16B are the lateral reinforcements 16 in the third embodiment. Is the same as. The vertical reinforcing bar 25 is formed longer than the vertical reinforcing bar 15 in the third embodiment.
一対の縦補強筋２５、２５は、配力筋群Ｇ２の下側において、第１スリーブ１３Ａ（前記一方の第２開口部）及び第２スリーブ１３Ｂ（前記他方の第２開口部）を挟んで設置される。具体的には、一対の縦補強筋２５、２５は、主筋１に平行であり、第１、第２スリーブ１３Ａ、１３Ｂ（二つの第２開口部）を挟み、かつ、その外寸が第１、第２囲繞補強筋１４Ａ、１４Ｂ（＝囲繞補強筋１４）の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが配力筋２の配筋時に複数の配力筋２と結束される。 The pair of vertical reinforcing bars 25, 25 sandwich the first sleeve 13A (the one second opening) and the second sleeve 13B (the other second opening) below the force distribution group G2. Is installed. Specifically, the pair of vertical reinforcing bars 25, 25 is parallel to the main bar 1, sandwiches the first and second sleeves 13A, 13B (two second openings), and has an outer dimension of the first. , The second reinforcement reinforcements 14A, 14B (= reinforcement reinforcement 14) are arranged so as to be substantially equal to the outer dimensions B2 of the two facing sides, and each of the reinforcement reinforcements 2 has a plurality of force distributions. It is united with muscle 2.
一対の第１横補強筋１６Ａ、１６Ａは、主筋群Ｇ１の上側において、第１スリーブ１３Ａ（前記一方の第２開口部）を挟んで設置される。具体的には、一対の第１横補強筋１６Ａ、１６Ａは、配力筋２に平行であり、第１スリーブ１３Ａ（前記一方の第２開口部）を挟み、かつ、その内寸が第１囲繞補強筋１４Ａ（＝囲繞補強筋１４）の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが複数の主筋１に取り付けされる（結束される）。 The pair of first lateral reinforcing bars 16A, 16A are installed above the main bar group G1 with the first sleeve 13A (the one second opening) interposed therebetween. Specifically, the pair of first lateral reinforcing bars 16A, 16A are parallel to the force distributing muscles 2, sandwich the first sleeve 13A (the one second opening), and have an inner size of the first. The reinforcement reinforcement 14A (=reinforcement reinforcement 14) is arranged so as to be approximately equal to the outer dimension B2 of two opposing side portions, and each is attached (bound) to a plurality of main reinforcements 1.
一対の第２横補強筋１６Ｂ、１６Ｂは、主筋群Ｇ１の上側において、第２スリーブ１３Ｂ（前記他方の第２開口部）を挟んで設置される。具体的には、一対の第２横補強筋１６Ｂ、１６Ｂは、配力筋２に平行であり、第２スリーブ１３Ｂ（前記他方の第２開口部）を挟み、かつ、その内寸が第２囲繞補強筋１４Ｂ（＝囲繞補強筋１４）の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが複数の主筋１に取り付けされる（結束される）。 The pair of second lateral reinforcing bars 16B and 16B are installed above the main bar group G1 with the second sleeve 13B (the other second opening) interposed therebetween. Specifically, the pair of second lateral reinforcing bars 16B, 16B are parallel to the power distributing muscles 2, sandwich the second sleeve 13B (the second opening of the other side), and have an inner dimension that is the second. The reinforcement reinforcement 14B (= reinforcement reinforcement 14) is arranged so as to be approximately equal to the outer dimensions B2 of the two opposing side portions, and each is attached (bound) to a plurality of main reinforcements 1.
第１囲繞補強筋１４Ａは、第１スリーブ１３Ａ（前記一方の第２開口部）を囲繞し、一対の縦辺部１４ａ、１４ｂが主筋１に平行となり、かつ、一対の横辺部１４ｃ、１４ｄが配力筋２に平行となるように配置され、一対の縦辺部１４ａ、１４ｂが一対の縦補強筋２５、２５に取り付けられ、一対の横辺部１４ｃ、１４ｄが一対の第１横補強筋１６Ａ、１６Ａに取り付けられる。具体的には、一対の縦辺部１４ａ、１４ｂは一対の縦補強筋２５、２５上に配置されて一対の縦補強筋２５、２５に結束され、一対の横辺部１４ｃ、１４ｄは一対の第１横補強筋１６Ａ、１６Ａの内側に配置されて一対の第１横補強筋１６Ａ、１６Ａに結束される。 The first surrounding reinforcing bar 14A surrounds the first sleeve 13A (the one second opening), the pair of vertical side parts 14a and 14b are parallel to the main bar 1, and the pair of lateral side parts 14c and 14d. Are arranged so as to be parallel to the force distribution muscle 2, the pair of vertical side portions 14a and 14b are attached to the pair of vertical reinforcing ribs 25 and 25, and the pair of horizontal side portions 14c and 14d are the pair of first lateral reinforcing portions. Attached to the muscles 16A, 16A. Specifically, the pair of vertical side portions 14a and 14b are arranged on the pair of vertical reinforcing ribs 25 and 25 and are bound to the pair of vertical reinforcing ribs 25 and 25, and the pair of horizontal side portions 14c and 14d are paired. It is arranged inside the first lateral reinforcing bars 16A, 16A and is bound to the pair of first lateral reinforcing bars 16A, 16A.
第２囲繞補強筋１４Ｂは、第２スリーブ１３Ｂ（前記他方の第２開口部）を囲繞し、一対の縦辺部１４ａ、１４ｂが主筋１に平行となり、かつ、一対の横辺部１４ｃ、１４ｄが配力筋２に平行となるように配置され、一対の縦辺部１４ａ、１４ｂが一対の縦補強筋２５、２５に取り付けられ、一対の横辺部１４ｃ、１４ｄが一対の第２横補強筋１６Ｂ、１６Ｂに取り付けられる。具体的には、一対の縦辺部１４ａ、１４ｂは一対の縦補強筋２５、２５上に配置されて一対の縦補強筋２５、２５に結束され、一対の横辺部１４ｃ、１４ｄは一対の第２横補強筋１６Ｂ、１６Ｂの内側に配置されて一対の第２横補強筋１６Ｂ、１６Ｂに結束される。 The second surrounding reinforcing bar 14B surrounds the second sleeve 13B (the other second opening), the pair of vertical sides 14a, 14b are parallel to the main bar 1, and the pair of lateral sides 14c, 14d. Are arranged so as to be parallel to the force distribution muscles 2, the pair of vertical side portions 14a, 14b are attached to the pair of vertical reinforcing ribs 25, 25, and the pair of horizontal side portions 14c, 14d are a pair of second lateral reinforcing portions. Attached to the muscles 16B, 16B. Specifically, the pair of vertical side portions 14a and 14b are arranged on the pair of vertical reinforcing ribs 25 and 25 and are bound to the pair of vertical reinforcing ribs 25 and 25, and the pair of horizontal side portions 14c and 14d are paired. It is arranged inside the second lateral reinforcing bars 16B, 16B and is bound to the pair of second lateral reinforcing bars 16B, 16B.
なお、上端筋の場合には、例えば次のように構成される。一対の縦補強筋２５、２５は、主筋１に平行であり、第１、第２スリーブ１３Ａ、１３Ｂ（二つの第２開口部）を挟み、かつ、その内寸が第１、第２囲繞補強筋１４Ａ、１４Ｂ（＝囲繞補強筋１４）の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが複数の配力筋２に取り付けられる（結束される）。一対の第１横補強筋１６Ａ、１６Ａは、配力筋２に平行であり、第１スリーブ１３Ａ（前記一方の第２開口部）を挟み、かつ、その外寸が第１囲繞補強筋１４Ａ（＝囲繞補強筋１４）の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが主筋１の配筋時に複数の主筋１と結束される。一対の第２横補強筋１６Ｂ、１６Ｂは、配力筋２に平行であり、第２スリーブ１３Ｂ（前記他方の第２開口部）を挟み、かつ、その外寸が第２囲繞補強筋１４Ｂ（＝囲繞補強筋１４）の対向する二つの辺部の外寸Ｂ２とほぼ等しくなるように配置され、それぞれが主筋１の配筋時に複数の主筋１と結束される。さらに、第１囲繞補強筋１４Ａは、第１スリーブ１３Ａ（前記一方の第２開口部）を囲繞すると共に、一対の横辺部１４ｃ、１４ｄが一対の第１横補強筋１６Ａ、１６Ａ上に配置されて一対の第１横補強筋１６Ａ、１６Ａに結束され、一対の縦辺部１４ａ、１４ｂが一対の縦補強筋２５、２５の内側に配置されて一対の縦補強筋２５、２５に結束される。第２囲繞補強筋１４Ｂは、第２スリーブ１３Ｂ（前記他方の第２開口部）を囲繞すると共に、一対の横辺部１４ｃ、１４ｄが一対の第２横補強筋１６Ｂ、１６Ｂ上に配置されて一対の第２横補強筋１６Ｂ、１６Ｂに結束され、一対の縦辺部１４ａ、１４ｂが一対の縦補強筋２５、２５の内側に配置されて一対の縦補強筋２５、２５に結束される。 In addition, in the case of the upper end streak, for example, it is configured as follows. The pair of vertical reinforcing bars 25, 25 is parallel to the main bar 1, sandwiches the first and second sleeves 13A, 13B (two second openings), and has inner dimensions of the first and second surrounding reinforcements. The muscles 14A and 14B (=encircling reinforcement muscles 14) are arranged so as to be approximately equal to the outer dimensions B2 of the two opposing side portions, and each is attached (bound) to the plurality of force distributing muscles 2. The pair of first lateral reinforcing bars 16A, 16A are parallel to the force distributing muscles 2, sandwich the first sleeve 13A (the one second opening), and the outer size thereof is the first surrounding reinforcing bar 14A ( = Arranged so as to be approximately equal to the outer dimensions B2 of the two opposing side portions of the surrounding reinforcing bar 14), and each of them is bound to the plurality of main bars 1 when the main bars 1 are arranged. The pair of second lateral reinforcing bars 16B, 16B are parallel to the force distributing muscles 2 and sandwich the second sleeve 13B (the other second opening), and the outer size thereof is the second surrounding reinforcing bar 14B ( = Arranged so as to be approximately equal to the outer dimensions B2 of the two opposing side portions of the surrounding reinforcing bar 14), and each of them is bound to the plurality of main bars 1 when the main bars 1 are arranged. Further, the first surrounding reinforcing bar 14A surrounds the first sleeve 13A (the one second opening), and the pair of lateral side portions 14c, 14d are arranged on the pair of first lateral reinforcing bars 16A, 16A. And is bound to the pair of first horizontal reinforcing bars 16A and 16A, and the pair of vertical side portions 14a and 14b is arranged inside the pair of vertical reinforcing bars 25 and 25 to be bound to the pair of vertical reinforcing bars 25 and 25. It The second surrounding reinforcing bar 14B surrounds the second sleeve 13B (the other second opening), and the pair of lateral sides 14c, 14d are arranged on the pair of second lateral reinforcing bars 16B, 16B. The pair of second horizontal reinforcing bars 16B and 16B are bound together, and the pair of vertical side portions 14a and 14b are arranged inside the pair of vertical reinforcing bars 25 and 25 to be bound to the pair of vertical reinforcing bars 25 and 25.
図１０は、第４実施形態に係る鉄筋コンクリートスラブの開口部補強構造に対応する従来の鉄筋コンクリートスラブの開口部補強構造の一例を示す図である。第４実施形態と共通する要素については同一の符号を用いてその説明は省略する。図１０に示されるように、従来の開口補強構造においては、前記開口補強筋として、一対の縦補強筋２５、２５と、一対の第１横補強筋１６Ａ、１６Ａと、一対の第２横補強筋１６Ｂ、１６Ｂと、八つの第１斜め補強筋１８Ａと、四つの第２斜め補強筋１８Ｂと、が用いられていた。八つの第１斜め補強筋１８Ａは、所定の長さを有し、主筋１及び配力筋２に対して傾斜しており、下端筋と上端筋との間において第１スリーブ１３Ａ（前記一方の第２開口部）及び第２スリーブ１３Ｂ（前記他方の第２開口部）を囲むように設置される。四つの第２斜め補強筋１８Ｂは、第１斜め補強筋１８Ａよりも長い所定の長さを有し、主筋１及び配力筋２に対して傾斜しており、下端筋と上端筋との間において第１スリーブ１３Ａ（前記一方の第２開口部）と第２スリーブ１３Ｂ（前記他方の第１開口部）との間に設置される。したがって、作業者は、八つの第１斜め補強筋１８Ａ及び四つの第２斜め補強筋１８Ｂを設けるため、所定の長さに切断された１２本の鋼棒のそれぞれを主筋１及び配力筋２に対して傾斜させて適切な位置に配置すると共に、１２本の鋼棒のそれぞれを主筋１、配力筋２、縦補強筋２５、第１横補強筋１６Ａ及び／又は第２横補強筋１６Ｂに結束する必要がある。このため、前記開口補強筋の設置作業に手間がかかる。 FIG. 10: is a figure which shows an example of the opening reinforcement structure of the conventional reinforced concrete slab corresponding to the opening reinforcement structure of the reinforced concrete slab which concerns on 4th Embodiment. The same elements as those in the fourth embodiment are designated by the same reference numerals and the description thereof will be omitted. As shown in FIG. 10, in the conventional opening reinforcement structure, as the opening reinforcement, a pair of vertical reinforcements 25, 25, a pair of first lateral reinforcements 16A, 16A, and a pair of second lateral reinforcements. The muscles 16B and 16B, the eight first diagonal reinforcing muscles 18A, and the four second diagonal reinforcing muscles 18B were used. The eight first diagonal reinforcing reinforcements 18A have a predetermined length, are inclined with respect to the main reinforcement 1 and the force distribution reinforcement 2, and are located between the lower end reinforcement and the upper end reinforcement 13A. It is installed so as to surround the second opening) and the second sleeve 13B (the other second opening). The four second diagonal reinforcing bars 18B have a predetermined length longer than that of the first diagonal reinforcing bars 18A, are inclined with respect to the main bar 1 and the distribution muscle 2, and are located between the lower end bar and the upper end bar. Is installed between the first sleeve 13A (the one second opening) and the second sleeve 13B (the other first opening). Therefore, since the worker provides the eight first diagonal reinforcing bars 18A and the four second diagonal reinforcing bars 18B, each of the twelve steel rods cut into a predetermined length is provided with the main bar 1 and the force distributing bar 2. The steel rods are arranged at appropriate positions with respect to each other, and each of the twelve steel bars is provided with a main bar 1, a distribution bar 2, a vertical reinforcing bar 25, a first horizontal reinforcing bar 16A and/or a second horizontal reinforcing bar 16B. Need to be united. Therefore, it takes a lot of time to install the opening reinforcing bar.
これに対し、第４実施形態に係る鉄筋コンクリートスラブの開口部補強構造では、１２本の鋼棒を第１、第２斜め補強筋１８Ａ、１８Ｂとして設置することに代えて、下端筋側及び上端筋側のそれぞれに第１スリーブ１３Ａ（前記一方の第２開口部）を囲繞する第１囲繞補強筋１４Ａ及び第２スリーブ１３Ｂ（前記他方の第２開口部）を囲繞する第２囲繞補強筋１４Ｂを設置すればよい。第１、第２囲繞補強筋１４Ａ、１４Ｂの設置は、１２個の鋼棒（すなわち、第１、第２斜め補強筋１８Ａ、１８Ｂ）の設置に比べて容易である。したがって、第４実施形態に係る鉄筋コンクリートスラブの開口部補強構造（図９）によれば、従来の鉄筋コンクリートスラブの開口部補強構造（図１０）に比べて、開口補強筋の設置作業の手間が大幅に軽減され、配筋作業性が向上する。 On the other hand, in the opening reinforcing structure of the reinforced concrete slab according to the fourth embodiment, instead of installing 12 steel rods as the first and second diagonal reinforcing bars 18A and 18B, the lower reinforcing bar side and the upper reinforcing bar are provided. A first surrounding reinforcing bar 14A surrounding the first sleeve 13A (the one second opening) and a second surrounding reinforcing bar 14B surrounding the second sleeve 13B (the other second opening) on each side. Just install it. The installation of the first and second surrounding reinforcing bars 14A and 14B is easier than the installation of 12 steel rods (that is, the first and second diagonal reinforcing bars 18A and 18B). Therefore, according to the opening reinforcing structure (FIG. 9) of the reinforced concrete slab according to the fourth embodiment, compared to the conventional opening reinforcing structure (FIG. 10) of the reinforced concrete slab, the labor for installing the opening reinforcing bar is significantly increased. The workability of bar arrangement is improved.
なお、第４実施形態に係る鉄筋コンクリートスラブの開口部補強構造において、前記他方の第２開口部が主筋１ｃ、１ｄ及び配力筋２ａ、２ｂが切断されることによって形成される場合には、一対の縦補強筋２５、２５、一対の第１横補強筋１６Ａ、１６Ａ及び一対の第２横補強筋１６Ｂ、１６Ｂに代えて、一対の第１縦補強筋、一対の第２縦補強筋及び一対の横補強筋が用いられる。前記一対の第１縦補強筋は、主筋１に平行であり、第１スリーブ１３Ａ（前記一方の第２開口部）を挟んで設置され、前記一対の第２縦補強筋は、主筋１に平行であり、第２スリーブ１３Ｂ（前記他方の第２開口部）を挟んで設置され、前記一対の横補強筋は、配力筋２に平行であり、第１スリーブ１３Ａ（前記一方の第２開口部）及び第２スリーブ１３Ｂ（前記他方の第２開口部）を挟んで設置される。 In addition, in the opening reinforcing structure of the reinforced concrete slab according to the fourth embodiment, when the other second opening is formed by cutting the main bars 1c, 1d and the distribution bars 2a, 2b, Instead of the vertical reinforcements 25, 25, the pair of first horizontal reinforcements 16A, 16A and the pair of second horizontal reinforcements 16B, 16B, a pair of first vertical reinforcements, a pair of second vertical reinforcements and a pair of The horizontal reinforcement of is used. The pair of first vertical reinforcing bars are parallel to the main bar 1 and are installed with the first sleeve 13A (the one second opening) interposed therebetween, and the pair of second vertical reinforcing bars are parallel to the main bar 1. And the pair of lateral reinforcing bars are parallel to the force distribution muscles 2, and the first sleeve 13A (the second opening of the one side) is installed with the second sleeve 13B (the other second opening of the other side) interposed therebetween. Part) and the second sleeve 13B (the second opening of the other side).
以上、本発明の実施形態及びその変形例について説明したが、本発明は上述の実施形態や変形例に限定されるものではなく、本発明の技術的思想に基づいて更なる変形や変更が可能である。 Although the embodiment of the present invention and the modified example thereof have been described above, the present invention is not limited to the above-described embodiment and the modified example, and further modifications and changes can be made based on the technical idea of the present invention. Is.
１…主筋
２…配力筋
３，３Ａ，３Ｂ，１３，１３Ａ，１３Ｂ…スリーブ
４，４Ａ，４Ｂ，１４，１４Ａ，１４Ｂ…囲繞補強筋
４ａ，４ｂ，１４ａ，１４ｂ…縦辺部
４ｃ，４ｄ，１４ｃ，１４ｄ…横辺部
４ｅ〜４ｈ，１４ｅ〜１４ｈ…斜辺部
６，１６，１６Ａ，１６Ｂ…横補強筋
１５，２５…縦補強筋
1... Main muscle 2... Distribution muscle 3,3A, 3B, 13, 13A, 13B... Sleeve 4, 4A, 4B, 14, 14A, 14B... Encircling reinforcement muscle 4a, 4b, 14a, 14b... Vertical side part 4c, 4d , 14c, 14d... Horizontal side portions 4e to 4h, 14e to 14h... Inclined side portions 6, 16, 16A, 16B... Horizontal reinforcing bars 15, 25... Vertical reinforcing bars
Claims (6)
前記囲繞補強筋は、平面視で八角形状に形成され、その一対の縦辺部が前記鉄筋コンクリートスラブの主筋に平行となり、かつ、その一対の横辺部が前記鉄筋コンクリートスラブの配力筋に平行となるように設置される、
鉄筋コンクリートスラブの開口部補強構造。 Includes a reinforcement reinforcement surrounding the opening of the reinforced concrete slab,
The surrounding reinforcing bars are formed in an octagonal shape in a plan view, and the pair of vertical sides are parallel to the main bars of the reinforced concrete slab, and the pair of horizontal sides are parallel to the reinforcing bars of the reinforced concrete slab. Will be installed,
Opening reinforcement structure for reinforced concrete slabs.
前記囲繞補強筋は、前記一対の縦辺部が前記一対の縦補強筋に取り付けられると共に前記一対の横辺部が前記開口部を挟む二つの配力筋に取り付けられる、請求項１又は２に記載の鉄筋コンクリートスラブの開口部補強構造。 While further sandwiching the opening, each further includes a pair of vertical reinforcing bars parallel to the main bar,
The said reinforcement|strengthening reinforcement is attached to the said pair of vertical sides with the said pair of vertical side parts, and is attached to the two force distribution muscles which pinch|interpose the said opening part with said pair of horizontal sides. Reinforced concrete slab opening reinforcement structure.
前記囲繞補強筋は、前記一対の縦辺部が前記開口部を挟む二つ主筋に取り付けられると共に前記一対の横辺部が前記一対の横補強筋に取り付けられる、請求項１又は２に記載の鉄筋コンクリートスラブの開口部補強構造。 While further sandwiching the opening, each further includes a pair of lateral reinforcing bars parallel to the force distributing muscles,
The said reinforcement|surrounding reinforcement is a pair of vertical side part is attached to the two main reinforcements which pinch|interpose the said opening part, and the said pair of horizontal side parts is attached to the said pair of horizontal reinforcement, The Claim 1 or 2 of Claim 1 or 2. Opening reinforcement structure for reinforced concrete slabs.
前記開口部を挟むと共にそれぞれが前記配力筋に平行な一対の横補強筋と、
をさらに含み、
前記囲繞補強筋は、前記一対の縦辺部が前記一対の縦補強筋に取り付けられると共に前記一対の横辺部が前記一対の横補強筋に取り付けられる、請求項１又は２に記載の鉄筋コンクリートスラブの開口部補強構造。 A pair of vertical reinforcing bars, each of which sandwiches the opening and is parallel to the main bar,
A pair of lateral reinforcing bars, each of which sandwiches the opening and is parallel to the distribution muscle,
Further including,
The reinforced concrete slab according to claim 1 or 2, wherein the pair of vertical sides is attached to the pair of vertical reinforcements and the pair of horizontal sides is attached to the pair of horizontal reinforcements. Opening reinforcement structure.
平面視で八角形状に形成され、
前記開口部を囲繞し、一対の縦辺部が前記鉄筋コンクリートスラブの主筋又は前記主筋に平行な鉄筋に取り付けられ、かつ、一対の横辺部が前記鉄筋コンクリートスラブの配力筋又は前記配力筋に平行な鉄筋に取り付けられるように構成されている、
開口補強筋。 An opening reinforcing bar provided around the opening of the reinforced concrete slab,
It is formed into an octagonal shape in plan view,
Surrounding the opening, a pair of vertical sides is attached to a main bar of the reinforced concrete slab or a reinforcing bar parallel to the main bar, and a pair of horizontal sides is a reinforcing bar of the reinforced concrete slab or the distributing bar. It is configured to be attached to parallel reinforcing bars,
Opening reinforcement.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001107508A (en) * | 1999-10-12 | 2001-04-17 | Nishimatsu Constr Co Ltd | Hole reinforcing member and hole reinforcement structure |
| JP2013112999A (en) * | 2011-11-29 | 2013-06-10 | Kagawa Univ | Opening reinforcement structure for slab |
| JP2014122504A (en) * | 2012-12-21 | 2014-07-03 | Aoki Asunaro Kensetsu Kk | Reinforcing fitting and reinforced concrete perforated beam comprising the same |
| JP2015190103A (en) * | 2014-03-27 | 2015-11-02 | 大和ハウス工業株式会社 | Opening reinforcement structure for rc beam |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001107508A (en) * | 1999-10-12 | 2001-04-17 | Nishimatsu Constr Co Ltd | Hole reinforcing member and hole reinforcement structure |
| JP2013112999A (en) * | 2011-11-29 | 2013-06-10 | Kagawa Univ | Opening reinforcement structure for slab |
| JP2014122504A (en) * | 2012-12-21 | 2014-07-03 | Aoki Asunaro Kensetsu Kk | Reinforcing fitting and reinforced concrete perforated beam comprising the same |
| JP2015190103A (en) * | 2014-03-27 | 2015-11-02 | 大和ハウス工業株式会社 | Opening reinforcement structure for rc beam |
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