JP3750056B2 - Fixing method of column head reinforcement - Google Patents

Description

【００２３】
（考察）本計測結果に対し、「各種アンカーボルトの設計（日本建築学会）」を適用する。許容引張力は、ガス圧接節定着工法の中央位置は支圧破壊によって決まるが、１８０°曲げフックと、ガス圧接節定着工法の中間、隅位置はコンクリートのコーン状破壊により決定される。又、本実験結果では、引張耐力は、１８０°曲げフックとガス圧接節定着工法の中央位置は鉄筋の降伏によって決まり、１８０°曲げフックとガス圧接節定着工法の中間、隅位置はコンクリートのコーン状破壊により決定されると考えられる。
【００２４】
上記表１より、１８０°曲げフックの中央、中間位置では、引張耐力は許容引張力の１．５〜２．０倍程度であった。又、ガス圧接節定着工法の中央、中間位置では、引き抜き試験による引張耐力は許容引張力の１．５〜１．８倍程度であった。
【００２５】
（まとめ）本実験より以下のことが得られた。又、先端形状による比較を図９に示す。
▲１▼ 本実験では、ガス圧接節定着工法は、場所によっては１８０°曲げフック以上の耐力を有しており、更にその圧接節の効果は図８より、１８０°曲げフックより変位量を小さく留めていることが確認できた。
▲２▼ ネジナット定着工法に関しても、ガス圧接節定着工法とほぼ同等の耐力を有すると考えられる。
【００２６】
【発明の効果】
以上説明したように、本発明は、柱頭部における柱主筋の上端部要所にガス圧接又は定着ナットによる膨出部を形成し、この膨出部に当接し且つ当該膨出部を挟むようにして上下にフープを配筋し、前記膨出部は梁主筋の位置を見込んで位置決めされ、前記フープの上或は下に梁主筋を当接させて配筋するようにしたので、柱主筋の上端部は、間隔の狭い２本のフープで締め付けられるため堅固に定着されることになり、又これら２本のフープは膨出部を介して柱主筋の押し込み、引き抜きに対して抵抗作用をなす。そして、次のような優れた効果も得られる。
（ａ）精度の高い確実な配筋施工が可能である。
（ｂ）柱頭部において梁筋がある場合、柱と梁の配筋組立が容易である。
（ｃ）スラブに傾斜がある場合でも、定着部のレベルが容易に調整可能である。
（ｄ）柱頂部からの打設コンクリートの充填性が良好となる。
（ｅ）定着節の形状、大きさを適宜設計に応じて設定することが可能である。
（ｆ）ネジ節鉄筋等の高価な特殊材料を使う必要がない。
（ｇ）鉄骨柱の根巻きコンクリート部にも適用した場合、鉄骨柱の建て込みが容易になる。
【図面の簡単な説明】
【図１】本発明に係る柱頭部鉄筋の定着工法の実施形態を示す概略断面図
【図２】図１におけるＳ部のＸ方向拡大図
【図３】図１におけるＳ部のＹ方向拡大図
【図４】本発明の他の実施形態を示す要部の概略図
【図５】根巻きコンクリートに適用した場合の説明図
【図６】定着工法実験における定着タイプの説明図
【図７】供試体を示すもので、（ａ）は正面図、（ｂ）は側面図
【図８】柱主筋の先端形状Ｔｙｐｅによる比較図
【図９】従来例を示すもので、（ａ）は柱・梁接合部の横断面図、（ｂ）は同縦断面図
【符号の説明】
１…柱主筋
２…フープ
２ａ…接合部フープ
２ｂ…梁主筋受けフープ
３…梁上端主筋
４…膨出部
５…後組みの梁主筋
６…スターラップ
７…定着ナット
８…鉄骨柱
９…根巻きコンクリート[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing method for column head reinforcing bars on the top floor of a building or the like.
[0002]
[Prior art]
In a reinforced concrete building, when fixing the column main reinforcement of the column head on the top floor into the column / beam joint, conventionally, for example, the required fixing length of the column main reinforcement A as shown in FIGS. In order to ensure the above, the hook B is formed by bending the upper end portion of the columnar reinforcement A by 180 ° or 90 °. However, in this fixing method, the column main reinforcement A and the beam main reinforcement C that crosses the column main reinforcement A are complicated, and the arrangement work becomes complicated and the filling property of the cast concrete also deteriorates. In addition, in the case of a sloped roof where the slab on the top floor is inclined, excessive or insufficient lengths or irregularities occur at the upper end of the column main reinforcement A, and a gap is formed between the beam main reinforcement C or play in the upper hoop D. The trouble that the column main muscle A cannot be firmly fixed occurs frequently. Then, even when root-rolled concrete is constructed on a steel column, if there is a hook on the main bar of the root-wrapped concrete part, there is also a problem that the workability is not good when the steel column is built.
[0003]
[Problems to be solved by the invention]
The present invention has been made in view of such a conventional situation. The positioning of the fixing portion is easy, the head of the column main muscle can be firmly fixed with a simple structure, and the beam bars and the steel frames cross or cross. An object of the present invention is to provide a fixing method for a column head reinforcing bar, which can be easily arranged even in the case where they are arranged close to each other.
[0004]
[Means for Solving the Problems]
As a technical means for achieving the above object, the present invention forms a bulging portion by gas pressure welding or a fixing nut in the vicinity of the upper end portion of the column main bar at the column head, contacts the bulging portion , and The gist of the fixing method of the column head reinforcing bar is that the hoops are arranged vertically so as to sandwich the part .
In addition, in the fixing method of this column head rebar,
(1) The bulging portion is positioned in anticipation of the position of the beam main bar that intersects with the column main bar, and the bar main bar is brought into contact with or above the hoop for placement.
(2) The bulging portion should be at least about twice the diameter of the columnar main bar,
It is characterized by.
As concrete means of fixation method of pillar head reinforcement,
(A) a step of striking a pillar main bar having a length that allows at least a predetermined cover thickness to be taken from the top of the pillar head;
(B) a step of depositing a hoop in advance under the pillar main bars;
(C) forming a bulging portion by gas pressure welding or a fixing nut at a required position of the upper end portion of the column main bar;
(D) a step of arranging the hoop up and down so as to contact the bulging portion and sandwich the bulging portion ;
(E) placing the beam main bar on the upper hoop;
It is a gist to contain at least.
Furthermore, when the leg part of a steel column is hardened with the root winding concrete, the gist of the fixing method of the root winding concrete part head reinforcing bar arranged in the root winding concrete.
[0005]
In the present invention, a bulging portion by gas pressure welding or a fixing nut is formed at a required position of the upper end portion of the column main reinforcement, and a hoop is arranged vertically so as to sandwich the bulging portion, thereby firmly fixing the upper end portion of the column main reinforcement. Can be fixed.
With the configuration (1), the beam main bars can be easily arranged, and the beam main bars are supported by the hoops, so that the bar arrangement strength is sufficiently obtained. This is fully guaranteed by configuration (2).
Further, even if the slab on the top floor of the building has a slope that is inclined by the above process, the fixing portion can be easily positioned, and the joint portion between the column main bar and the beam main bar can be easily constructed.
Furthermore, the fixing method of the column head reinforcing bar of the present invention can also be applied to the case where the leg portion of the steel column is hardened with root winding concrete.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a fixing method for column head reinforcing bars according to the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an embodiment in which the present invention is applied to a case where the slab has an inclination. 1 is a column main reinforcement, 2 is a hoop (band), the column main reinforcement 1 is a straight straight line, and the slab on the uppermost floor. Gas pressure welding is performed at the column base P so that the required height (about 200 mm) protrudes from the top, and a predetermined number of hoops 2 are deposited below the column base P before the gas pressure welding. These hoops 2 are arranged on the column main reinforcement 1 at a specified pitch after the column main reinforcement 1 is erected by gas pressure welding.
[0007]
After assembling the column form frame (not shown), before placing the beam upper main bar 3, a hoop 2a for the joint is provided at the upper end of the column main bar 1 below the beam upper main bar 3 and inside the beam. Deposit the number of provisions to be placed.
[0008]
After this, the column main reinforcement 1 is marked at a position lower than the required distance from the top of the slab (this distance is determined in consideration of the cover thickness of the beam main reinforcement and the diameter of the beam main reinforcement and the hoop). A bulging portion 4 having a size of at least about twice the diameter of the columnar reinforcement 1 is formed at each marking position (FIG. 2). In this embodiment, there is a main bar of the beam, but when there is no main bar of the beam, the position of the bulging portion is 11 cm to 15 cm below the top of the column concrete in consideration of the pushing and pulling force acting on the column head. Form. In this embodiment, it is about 13 cm. These bulging portions 4 can be formed by heating and pressurizing with a gas flame.
[0009]
After the bulging portion 4 is formed, the column main reinforcement 1 that is too long is cut as shown by a broken line in FIG. In this embodiment, the extra length is secured above the bulging portion and cut at a position about 4 cm lower than the top end of the slab.
[0010]
By the way, when the column main reinforcement 1 is gas-welded to the column base P, the bulging portion 4 is manufactured in advance at the upper end of the column main reinforcement 1 on the ground, and if the level can be accurately constructed in advance, the marking is performed. A process and the cutting process of the column main reinforcement 1 upper end part can be omitted.
[0011]
Thereafter, a beam main bar receiving hoop 2b is mounted on the bulging portion 4, and the beam main bar of the first assembly, that is, the beam upper end main bar 3 is arranged on the hoop 2b. At this time, the hoop 2b becomes the positioning of the beam upper main bar 3 and the level of the beam upper main bar 3 is easily secured. Further, since the beam upper main bar 3 is received by the bulging portion 4 through the hoop 2b, the stability is remarkably improved.
[0012]
Next, the beam main reinforcement 5 in the direction intersecting with the rear beam main reinforcement 4 is passed over the beam upper main reinforcement 3 in a perpendicular direction and arranged. The rear beam main reinforcing bar 5 corresponds to the beam upper main bar of the horizontal beam R (FIG. 3) perpendicular to the inclined beam Q including the beam upper main bar 3 of the previous assembly. Then, both the horizontal beam R and the inclined beam Q surround the upper and lower beam main bars, and the stirrups 6 (reinforcing bars) and 6a are arranged at prescribed pitches on both sides of the joint portion.
[0013]
Thereafter, the hoops 2a of the joints are allocated at a specified pitch. At this time, one hoop 2c is always brought into contact with and directly below the bulging portion 4. As a result, the bulging portion 4 is sandwiched between the hoop 2c and the beam main bar bearing hoop 2b. Since the upper end portion of the columnar reinforcement 1 is fastened by the two hoops 2b and 2c having a small interval, it is firmly fixed. Further, these two hoops 2 b and 2 c have a resistance action against the pushing and pulling of the column main reinforcement 1 through the bulging portion 4.
[0014]
After arranging the column bars and beam bars in this way, prescribed spacers (not shown) are respectively attached between the column mold frame and the beam mold frame, and the preparation of the placing concrete is completed. Since there is no hindrance hook as in the prior art at the joint between the column and the beam, the filling property of the cast concrete is improved.
[0015]
FIG. 4 shows another embodiment of the present invention, which is an example in which a fixing nut 7 is used as a bulging portion. That is, in this case, a threaded portion 1 a is formed by rolling on the upper end portion of the columnar reinforcing bar 1, a fixing nut 7 is fitted into the threaded portion 1 a at a predetermined position, and the hoops 2 b and 2 c are connected to the fixing nut 7. The column main reinforcement 1 is firmly fixed to the top and bottom, and the beam main reinforcement 3 is fixed by the support pressure by the fixing nut 7. The diameter of the fixing nut 7 is at least about twice the diameter of the column main reinforcement 1.
[0016]
Since the column and beam bar arrangement steps in the fixing nut 7 are the same as those in the above-described embodiment, the description thereof will be omitted, but in this embodiment also, the beam upper end main bar on the hoop 2b positioned above the fixing nut 7 3 can be easily secured, and the hoops 2b and 2c positioned above and below the fixing nut 7 and the fixing nut 7 can increase the resistance against pushing and pulling of the column main reinforcement 1.
[0017]
In any of the embodiments, the beam upper end main reinforcement 3 is described as being mounted on the upper hoop 2b sandwiching the bulging portion 4 (fixing nut 7). It may be attached along with. Further, as shown in FIG. 5, when the leg portion of the steel column 8 is solidified by the root-rolled concrete 9, it can also be applied to the bar arrangement structure of the root-wrapped concrete portion column head. The position of the bulging portion in this case is 11 cm to 15 cm from the top of the concrete, generally about 13 cm, in accordance with the position of the bulging portion when there is no beam main bar in the above, The extra length of the reinforcing bar is also secured in consideration of the minimum cover thickness of the reinforcing bar. By adopting this configuration, compared to conventional hook fixing, it is possible to smoothly embed steel pillars without hindering the hang-up due to the hook being hindered.
[0018]
A fixing / adhesion force verification experiment regarding the fixing method of the column head reinforcing bar according to the present invention was conducted, and an outline thereof will be described below.
(Experimental plan) In order to compare the pull-out strength of the fixing portion with that of the conventional method, the fixing type shown in FIG. 6 was set. SD345 and D22 were used for the column main reinforcement, and the fixing length was 13d so that the yielding of the reinforcing bars would not precede. Here, Type A is a 180 ° bending hook (conventional method), Type B is a straight line, and Type C is a gas pressure joint fixing method. The size of the bulging portion in this experiment was able to ensure a diameter of 45 mm.
[0019]
(Material characteristics) The column main bars and gas pressure contact parts used in this experiment were subjected to a material test and confirmed to have a predetermined strength. In addition, for concrete, in order to compare the fixability of the tip shape of the column main reinforcement, the experiment time was set with a target of 10 N / mm ² . In addition, the concrete compressive strength test result by on-site water curing on the test day was 9.9 N / mm ² .
[0020]
(Specimen and Experimental Apparatus) An example of the specimen is shown in FIGS. 7 (a) and 7 (b). The column main bars were subjected to a pull-out test so that the presence or absence of deformed bars could be confirmed and the difference depending on the concrete embedding position.
[0021]
(Experimental results) Table 1 shows a list of experimental results.
[0022]
[Table 1]

[0023]
(Discussion) “Design of various anchor bolts (Architectural Institute of Japan)” is applied to this measurement result. The allowable tensile force is determined by bearing failure at the center of the gas pressure joint fixing method, but the middle and corner positions of the 180 ° bending hook and the gas pressure joint fixing method are determined by concrete cone-like failure. Also, in this experimental result, the tensile strength is determined by the yield of the reinforcing bar at the center position of the 180 ° bending hook and gas pressure joint fixing method, the middle position of the 180 ° bending hook and gas pressure joint fixing method, and the corner position is the cone of concrete. It is thought that it is determined by the state destruction.
[0024]
From Table 1 above, the tensile strength was about 1.5 to 2.0 times the allowable tensile force at the center and middle position of the 180 ° bending hook. Further, at the middle and middle positions of the gas pressure joint fixing method, the tensile strength by the pull-out test was about 1.5 to 1.8 times the allowable tensile force.
[0025]
(Summary) The following was obtained from this experiment. FIG. 9 shows a comparison according to the tip shape.
(1) In this experiment, the gas pressure joint fixing method has a proof strength more than 180 ° bending hook depending on the location, and the effect of the pressure welding node is smaller than the 180 ° bending hook from FIG. It was confirmed that it was fastened.
(2) The screw nut fixing method is considered to have almost the same strength as the gas pressure joint fixing method.
[0026]
【The invention's effect】
As described above, the present invention forms a bulging portion by gas pressure welding or a fixing nut at the upper end portion of the column main bar at the column head, and comes into contact with the bulging portion and sandwiches the bulging portion. Since the hoop is arranged, the bulging part is positioned in anticipation of the position of the main beam of the beam, and the upper part of the column main bar is arranged by placing the main beam of the beam above or below the hoop. The two hoops are firmly fixed because they are tightened by two hoops having a narrow interval, and these two hoops have a resistance action against the pushing and pulling of the column main bars through the bulging portion. And the following excellent effects are also obtained.
(A) Accurate and reliable bar arrangement can be performed.
(B) When there is a beam bar at the column head, the bar and beam bar assembly is easy.
(C) Even when the slab is inclined, the level of the fixing unit can be easily adjusted.
(D) Fillability of the cast concrete from the top of the column becomes good.
(E) The shape and size of the fixing node can be appropriately set according to the design.
(F) It is not necessary to use expensive special materials such as screw joints.
(G) When it is applied also to a steel-cylinder root-wrapped concrete part, the steel column can be easily built.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an embodiment of a fixing method for a column head reinforcing bar according to the present invention. FIG. 2 is an enlarged view in the X direction of an S portion in FIG. FIG. 4 is a schematic view of the main part showing another embodiment of the present invention. FIG. 5 is an explanatory diagram when applied to a root-wrapped concrete. FIG. 6 is an explanatory diagram of a fixing type in a fixing method experiment. Fig. 8 is a front view, Fig. 8B is a side view. Fig. 8 is a comparative view based on the shape of the tip of a column main bar. Fig. 9 is a conventional example. Fig. 9A is a column / beam. Cross-sectional view of the joint, (b) is the vertical cross-sectional view [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Column main reinforcement 2 ... Hoop 2a ... Joint part hoop 2b ... Beam main reinforcement receiving hoop 3 ... Beam upper end main reinforcement 4 ... The bulging part 5 ... Rear assembly beam main reinforcement 6 ... Star wrap 7 ... Anchor nut 8 ... Steel column 9 ... Root Rolled concrete

Claims (5)

A bulging portion by gas pressure welding or a fixing nut is formed in the vicinity of the upper end portion of the column main bar at the column head, and a hoop is arranged vertically so as to contact the bulging portion and sandwich the bulging portion. Fixing method for column head reinforcement. 2. The fixing method for a column head reinforcing bar according to claim 1, wherein the bulging portion is positioned in anticipation of a position of a beam main bar that intersects with the column main bar, and the bar main bar is in contact with or above the hoop. The method for fixing a column head reinforcing bar according to claim 1 or 2, wherein the bulging portion is at least about twice the diameter of the column main reinforcing bar. A step of striking a column main bar having a length that allows a predetermined cover thickness to be taken from at least the top of the column head;
The process of depositing a hoop in advance below the pillar main bars,
Forming a bulging portion by gas pressure welding or a fixing nut at a required position of the upper end portion of the column main bar;
Arranging the hoop up and down so as to contact the bulging portion and sandwich the bulging portion ;
Placing the beam main bar on the upper hoop;
The fixing method of the columnar head reinforcing bar according to claim 1 including at least. The fixing method for a head-rolled concrete column head reinforcing bar according to claim 1, wherein, when the leg portion of the steel column is hardened with the root-wrapped concrete, the reinforcement is placed in the root-wrapped concrete.

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