JP2023111529A - Reinforcement method for utility pole - Google Patents
Reinforcement method for utility pole Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 31
- 230000002787 reinforcement Effects 0.000 title abstract description 48
- 239000000835 fiber Substances 0.000 claims abstract description 139
- 239000012948 isocyanate Substances 0.000 claims abstract description 55
- 150000002513 isocyanates Chemical class 0.000 claims abstract description 55
- 229920005862 polyol Polymers 0.000 claims abstract description 54
- 150000003077 polyols Chemical class 0.000 claims abstract description 54
- 239000012779 reinforcing material Substances 0.000 claims description 95
- 229920002803 thermoplastic polyurethane Polymers 0.000 claims description 39
- 230000003014 reinforcing effect Effects 0.000 claims description 16
- 239000007788 liquid Substances 0.000 claims description 15
- 239000006260 foam Substances 0.000 abstract description 40
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 abstract description 15
- 239000011347 resin Substances 0.000 abstract description 12
- 229920005989 resin Polymers 0.000 abstract description 12
- 239000000203 mixture Substances 0.000 abstract description 11
- 239000000463 material Substances 0.000 abstract description 9
- 239000007921 spray Substances 0.000 abstract description 6
- 238000002347 injection Methods 0.000 description 50
- 239000007924 injection Substances 0.000 description 50
- 239000011259 mixed solution Substances 0.000 description 17
- 239000011796 hollow space material Substances 0.000 description 6
- 238000010276 construction Methods 0.000 description 5
- 238000007599 discharging Methods 0.000 description 5
- 229920000049 Carbon (fiber) Polymers 0.000 description 3
- 239000004917 carbon fiber Substances 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- 239000004568 cement Substances 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- 239000004760 aramid Substances 0.000 description 1
- 229920006231 aramid fiber Polymers 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
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Abstract
Description
本発明は、電柱の補強方法に関する。 The present invention relates to a method for reinforcing utility poles.
地震や台風などの自然災害によって電柱が折れると、電線が切れて送電や配電が停止されてしまうことなどがあることに加え、建物が折れた電柱によって壊れることがある他、折れた電柱が道路に倒れると、住民が避難する際の障害になったり、緊急車両の通行の妨げとなって地域の復旧作業の遅れの原因になったりする。従って、こうした事態を防ぐために、電柱を折れにくくするための様々な方法が提案されており、本発明者らも、現在の電柱の主流である中空状のコンクリート製電柱の中空部に膨張性樹脂を充填して膨張させることによる補強方法を特許文献１において提案している。本発明者らが特許文献１において提案した方法は、例えば、ポリオールとイソシアネートのそれぞれをスプレーガンに供給し、ガンのノズル先端から両者を電柱の中空部に噴射することで発泡ウレタン樹脂を電柱の中空部に充填して膨張させることにより、電柱を内部から補強でき、施工に手間や時間がかからない優れた方法として評価されている。 When utility poles break due to natural disasters such as earthquakes and typhoons, power lines can be cut and power transmission and distribution stopped. If it collapses, it will become an obstacle for residents to evacuate, and it will hinder the passage of emergency vehicles and cause delays in the restoration work in the area. Therefore, in order to prevent such a situation, various methods have been proposed to make utility poles less likely to break. Patent Document 1 proposes a reinforcement method by filling and expanding the material. In the method proposed by the present inventors in Patent Document 1, for example, polyol and isocyanate are each supplied to a spray gun, and both are sprayed from the nozzle tip of the gun into the hollow part of the utility pole, thereby forming urethane foam resin on the utility pole. By filling the hollow part and expanding it, it is possible to reinforce the utility pole from the inside, and it is evaluated as an excellent method that does not require much labor and time for construction.
しかしながら、本発明者らが特許文献１において提案した方法を、例えば、ポリオールとイソシアネートの少なくとも一方に炭素繊維などの繊維補強材を添加して行おうとすると、スプレーガンの内部で繊維補強材が目詰まりを起こしてしまい、繊維補強材を含む発泡ウレタン樹脂を電柱の中空部に充填して膨張させることができなくなることがある。 However, if the method proposed by the present inventors in Patent Document 1, for example, is performed by adding a fiber reinforcing material such as carbon fiber to at least one of polyol and isocyanate, the fiber reinforcing material is not visible inside the spray gun. Clogging may occur, and it may not be possible to fill the hollow portion of the utility pole with the foamed urethane resin containing the fiber reinforcement and expand it.
そこで本発明は、スプレーガンを用いることなく、中空状のコンクリート製電柱の中空部に繊維補強材を含む発泡ウレタン樹脂を充填して膨張させることによる電柱の補強方法を提供することを目的とする。 SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for reinforcing a utility pole by filling the hollow portion of a hollow concrete utility pole with foamed urethane resin containing a fiber reinforcing material and expanding the resin without using a spray gun. .
上記の点に鑑みてなされた本発明は、請求項１記載の通り、中空状のコンクリート製電柱の中空部に繊維補強材を含む発泡ウレタン樹脂を充填して膨張させることによる電柱の補強方法であって、少なくとも一方に繊維補強材を添加したポリオールとイソシアネートを、空気流に乗せて混合し、両者の混合液を電柱の中空部に注入することで、繊維補強材を含む発泡ウレタン樹脂を充填して膨張させることによる方法である。 The present invention, which has been made in view of the above points, is a method for reinforcing a utility pole by filling the hollow portion of a hollow concrete utility pole with a foamed urethane resin containing a fiber reinforcing material and expanding it. Polyol and isocyanate, at least one of which is added with a fiber reinforcing material, are mixed in an air flow, and the mixture is injected into the hollow part of the utility pole to fill the foamed urethane resin containing the fiber reinforcing material. It is a method by inflating by
本発明によれば、中空状のコンクリート製電柱を折れにくくすることを、スプレーガンを用いることなく、繊維補強材を含む発泡ウレタン樹脂を電柱の中空部に充填して膨張させることで行うことができる。 According to the present invention, it is possible to make a hollow concrete utility pole less likely to break by filling the hollow portion of the utility pole with foamed urethane resin containing a fiber reinforcing material and expanding it without using a spray gun. can.
本発明の中空状のコンクリート製電柱の中空部に繊維補強材を含む発泡ウレタン樹脂を充填して膨張させることによる電柱の補強方法は、少なくとも一方に繊維補強材を添加したポリオールとイソシアネートを、空気流に乗せて混合し、両者の混合液を電柱の中空部に注入することで、繊維補強材を含む発泡ウレタン樹脂を充填して膨張させることによる方法である。 In the method of reinforcing a utility pole by filling the hollow portion of a hollow concrete utility pole with a foamed urethane resin containing a fiber reinforcing material and expanding it, at least one of the polyol and the isocyanate to which the fiber reinforcing material is added is mixed with air. In this method, they are mixed in a flow, and the mixed solution is injected into the hollow portion of the utility pole to fill and expand the foamed urethane resin containing the fiber reinforcing material.
本発明の電柱の補強方法において、少なくとも一方に繊維補強材を添加したポリオールとイソシアネートを、空気流に乗せて混合し、両者の混合液（即ち繊維補強材を含む発泡ウレタン樹脂となるもの）を電柱の中空部に注入することは、例えば、注入ホースを接続したミキシングヘッドを用いて行うことができる。以下、本発明の電柱の補強方法を、ミキシングヘッドに送液されてきた繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートを、空気流に乗せて混合し、両者の混合液を注入ホースの先端から吐出させ、電柱の側面に設けた注入孔から電柱の中空部に注入する方法を例にとって説明する。 In the method for reinforcing a utility pole of the present invention, a polyol and an isocyanate having a fiber reinforcing material added to at least one of them are mixed in an air flow, and a mixture of the two (that is, a foamed urethane resin containing a fiber reinforcing material) is produced. Injection into the hollow portion of the utility pole can be performed using, for example, a mixing head to which an injection hose is connected. Hereinafter, the method for reinforcing a utility pole of the present invention is performed by mixing the polyol with the added fiber reinforcing material and the isocyanate with the added fiber reinforcing material sent to the mixing head in an air flow, and injecting the mixed solution of both. A method of discharging from the tip of a hose and injecting into a hollow portion of a utility pole through an injection hole provided on the side of the utility pole will be described as an example.
図１は、本発明の電柱の補強方法において用いる、繊維補強材を含む発泡ウレタン樹脂を電柱の中空部に充填して膨張させるための注入ホースを接続したミキシングヘッドの一例の概略断面模式図である。このミキシングヘッドは、例えば市販の金属製であってよく、収容タンクから送液されてきた繊維補強材を添加したポリオールが空気流に供給され、そこにさらに収容タンクから送液されてきた繊維補強材を添加したイソシアネートが供給されることにより、両者が空気流に乗って攪拌されることで混合されながら例えばゴム製の注入ホースの先端に向かって導かれ、両者の混合液が注入ホースの先端から吐出される。ポリオールはイソシアネートよりも粘性が高いので、繊維補強材を添加したポリオールを先に空気流に供給して後から繊維補強材を添加したイソシアネートを供給する方が、逆の順序よりも両者を混合させやすい。繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートを混合し、両者の混合液を吐出させるための空気流の圧力は、例えば少なくとも０．０５ＭＰａとするのがよい。圧力が低すぎると、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合が十分に行われずに注入ホースの先端から吐出される恐れがある。注入ホースは、電柱の側面に設ける注入孔の孔径を考慮し、例えば内径が１０～２０ｍｍのものを用いるのがよい。その長さは、例えば１～３ｍとするのがよい。短すぎると、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合が十分に行われずに注入ホースの先端から吐出される恐れがある。長すぎると、電柱の中空部への繊維補強材を含む発泡ウレタン樹脂の所定分量の充填が完了するまでに膨張し始めてしまうことで均質な発泡体が形成されない恐れがある。また、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の電柱の中空部への注入を、例えば高所作業車の作業台から行う必要がある場合、作業台の限られたスペースでの作業の支障になる恐れがある。 FIG. 1 is a schematic cross-sectional view of an example of a mixing head connected to an injection hose for filling and expanding a hollow part of a utility pole with a foamed urethane resin containing a fiber reinforcing material, which is used in the utility pole reinforcement method of the present invention. be. This mixing head may be made of commercially available metal, for example, and the polyol added with the fiber reinforcing material sent from the storage tank is supplied to the air flow, and the fiber reinforcing material sent from the storage tank is further supplied to the air flow. By supplying the isocyanate to which the material is added, both are mixed by being agitated by the air flow and guided toward the tip of a rubber injection hose, for example, and the mixed solution of both is at the tip of the injection hose. is discharged from Since the polyol is more viscous than the isocyanate, feeding the fiber-reinforced polyol first into the air stream and then the fiber-reinforced isocyanate will cause the two to mix better than the reverse order. Cheap. The pressure of the air flow for mixing the polyol with the added fiber reinforcement and the isocyanate with the added fiber reinforcement and discharging the mixed liquid of the two is preferably, for example, at least 0.05 MPa. If the pressure is too low, the polyol containing the fiber reinforcing material and the isocyanate containing the fiber reinforcing material may not be sufficiently mixed and may be discharged from the tip of the injection hose. The injection hose preferably has an inner diameter of 10 to 20 mm, for example, considering the hole diameter of the injection hole provided on the side of the utility pole. Its length is preferably 1 to 3 m, for example. If it is too short, there is a risk that the fiber reinforcing material-added polyol and the fiber reinforcing material-added isocyanate will not be sufficiently mixed and will be discharged from the tip of the injection hose. If the length is too long, there is a risk that the hollow part of the utility pole will begin to expand before a predetermined amount of the foamed urethane resin containing the fiber reinforcing material is completely filled, and a homogeneous foam will not be formed. In addition, when it is necessary to inject a mixture of a polyol with a fiber reinforcement and an isocyanate with a fiber reinforcement into the hollow part of a utility pole, for example, from the workbench of an aerial work platform, the workbench is limited. It may interfere with work in the open space.
本発明の電柱の補強方法において用いるポリオールとイソシアネートは、例えば両者が３０～４０℃において１：０．８～１．５の重量割合で混合されることによって調製される発泡ウレタン樹脂が、中空状のコンクリート製電柱の中空部で膨張することで電柱を内部から補強することができるものであれば特段に限定されるものではなく、市販のものであってよい。発泡ウレタン樹脂のゲルタイム（ポリオールとイソシアネートが混合されてから膨張し始めるまでの時間）は、例えば２４０～４８０秒（４～８分）がよい。ゲルタイムが短すぎると、電柱の中空部への所定分量の発泡ウレタン樹脂の充填が完了するまでに膨張し始めてしまうことで均質な発泡体が形成されない恐れがある。ゲルタイムが長すぎると、発泡体が形成されるまでに時間がかかりすぎることで施工効率が悪くなる恐れがある。発泡ウレタン樹脂は、発泡体の標準密度（大気中で発泡させた場合の密度）が例えば５０～３００ｋｇ／ｍ３となるものがよい。標準密度が低すぎると、発泡体の強度が不足することで電柱を十分に補強できない恐れがある。標準密度が高すぎると、発泡体の靭性が低下することで脆性破壊されやすくなる恐れがある。ポリオールとイソシアネートの具体例としては、日本パフテム株式会社のノンフロンポリオールＦＦ５０２０－ＵＣと同社のイソシアネートＮＰ－９０の組み合わせ（約３５℃において１：１の重量割合で混合した場合に調製される発泡ウレタン樹脂はゲルタイムが約３００秒であって形成される発泡体は標準密度が約１９０ｋｇ／ｍ３である）を挙げることができる。 Polyol and isocyanate used in the method for reinforcing electric poles of the present invention are, for example, foamed urethane resin prepared by mixing them at a weight ratio of 1:0.8 to 1.5 at 30 to 40 ° C. It is not particularly limited as long as it can reinforce the utility pole from the inside by expanding in the hollow part of the utility pole made of concrete, and it may be a commercially available one. The gel time of the foamed urethane resin (the time from mixing the polyol and isocyanate to starting to expand) is preferably 240 to 480 seconds (4 to 8 minutes), for example. If the gel time is too short, the foam may begin to expand before the predetermined amount of urethane foam resin is completely filled into the hollow portion of the utility pole, and a homogeneous foam may not be formed. If the gel time is too long, it takes too long to form a foam, which may result in poor construction efficiency. The foamed urethane resin preferably has a standard foam density (density when foamed in air) of, for example, 50 to 300 kg/m 3 . If the standard density is too low, the strength of the foam may be insufficient to sufficiently reinforce the utility pole. If the standard density is too high, the toughness of the foam may be reduced, making it susceptible to brittle fracture. A specific example of polyol and isocyanate is a combination of non-Freon polyol FF5020-UC of Nippon Paftem Co., Ltd. and isocyanate NP-90 of the same company (urethane foam resin prepared when mixed at a weight ratio of 1:1 at about 35 ° C. has a gel time of about 300 seconds and the resulting foam has a standard density of about 190 kg/m 3 ).
本発明の電柱の補強方法において用いる繊維補強材は、東レ株式会社製の炭素短繊維（商品名「トレカカットファイバー」３ｍｍ長）に例示される炭素繊維の他、アラミド繊維やガラス繊維など、繊維補強材として市販されているものであってよく、これらを単独または複数種類を組み合わせて用いることができる。繊維補強材は、ポリオールとイソシアネートのいずれか一方だけに添加されてもよいし、両方に添加されてもよいが、繊維補強材を含む発泡ウレタン樹脂の重量に対して例えば１～４ｗｔ％になるように添加するのがよい。添加量が少なすぎると、添加することの効果が得られない恐れがある。添加量が多すぎると、全体にわたって繊維補強材が均一に分散した発泡体が得られない恐れがある（繊維補強材の塊が発泡体の下方に集積したりしやすくなる）。 The fiber reinforcing material used in the utility pole reinforcing method of the present invention includes carbon fibers exemplified by short carbon fibers manufactured by Toray Industries, Inc. (trade name "Torayca Cut Fiber" 3 mm length), aramid fibers, glass fibers, etc. Commercially available reinforcing materials may be used, and these may be used singly or in combination. The fiber reinforcing material may be added to either one of the polyol and the isocyanate, or may be added to both. should be added as follows. If the amount added is too small, there is a risk that the effect of the addition cannot be obtained. If the amount added is too large, it may not be possible to obtain a foam in which the fiber reinforcing material is evenly dispersed throughout (lumps of the fiber reinforcing material tend to accumulate at the bottom of the foam).
注入ホースの先端から吐出された繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の、電柱の側面に設けた注入孔からの電柱の中空部への注入は、中空部に充填された繊維補強材を含む発泡ウレタン樹脂が電柱の下端部から意図する高さまで膨張する分量で行う。この分量は、発泡体の標準密度と電柱の口径（例えば１０～５０ｃｍである）から算出することができる。中空状のコンクリート製電柱の長さは、通常、５～２０ｍであるが、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液は、繊維補強材を含む発泡ウレタン樹脂が電柱の下端部から上端部まで膨張する分量、即ち、電柱の中空部の全ての空間を発泡体が占める分量を注入する必要はなく、繊維補強材を含む発泡ウレタン樹脂が電柱の下端部から長さの例えば少なくとも２／３の高さまで膨張する分量を注入すればよい。地震や台風などの自然災害によって電柱が折れる場合、地際付近をはじめとする電柱の下端部から長さの１／２の高さまでの位置で折れることが多いからである。 Injection of a mixture of polyol with fiber reinforcement and isocyanate with fiber reinforcement discharged from the tip of the injection hose into the hollow part of the utility pole from the injection hole provided on the side of the utility pole The amount of urethane foam containing the filled fiber reinforcing material expands from the lower end of the utility pole to the intended height. This amount can be calculated from the standard density of the foam and the diameter of the utility pole (for example, 10-50 cm). The length of a hollow concrete utility pole is usually 5 to 20 m. It is not necessary to inject the amount that expands from the bottom end to the top end, that is, the amount that the foam occupies the entire space in the hollow part of the utility pole, and the foamed urethane resin containing the fiber reinforcement material extends from the bottom end of the utility pole. For example, an amount that expands to a height of at least 2/3 of the height is injected. This is because when a utility pole breaks due to a natural disaster such as an earthquake or a typhoon, it often breaks at a position from the lower end of the utility pole, such as near the ground, to a height half of the length.
補強対象とする中空状のコンクリート製電柱の長さが１２ｍの場合を例にとると、その中空部への繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の注入を、中空部に充填された繊維補強材を含む発泡ウレタン樹脂が電柱の下端部から少なくとも８ｍの高さまで膨張する分量で行う。この分量の繊維補強材を含む発泡ウレタン樹脂の中空部への充填は、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の１回の注入によって行わずに複数回の注入に小分けして行い、先の注入によって充填された繊維補強材を含む発泡ウレタン樹脂の膨張が完了した後、次の注入を行って、充填された繊維補強材を含む発泡ウレタン樹脂を膨張させるのがよい（即ち先に形成された発泡体の上に次に形成される発泡体を積み重ねる）。繊維補強材を含む発泡ウレタン樹脂が電柱の下端部から少なくとも８ｍの高さまで膨張する分量の注入を１回で行うと、繊維補強材を含む発泡ウレタンが自重によって電柱の下端部から少なくとも８ｍの高さまで膨張せず、下方から上方に向かって密度が低く、繊維補強材が下方に集積した、不均質な発泡体が形成されやすくなる。電柱の下端部から少なくとも８ｍの高さまでの中空部の空間を、全体にわたって繊維補強材が均一に分散した均一な密度を有する均質な発泡体が占めるようにするためには、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の１回の注入によって中空部に充填する繊維補強材を含む発泡ウレタン樹脂の分量は、前述した発泡体の標準密度が５０～３００ｋｇ／ｍ３となる発泡ウレタン樹脂の場合、電柱の３～５ｍの高さまで膨張する分量とし（電柱の口径に依るが概ね１５～３５Ｋｇ程度）、この分量の注入を複数回行うのがよい。繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の１回の注入によって中空部に充填する繊維補強材を含む発泡ウレタン樹脂の分量を電柱の３ｍ未満の高さまで膨張する分量とすると、注入回数が増えてしまい施工効率が悪くなる恐れがある。例えば、長さが１２ｍの電柱の下端部から８ｍの高さまでの中空部の空間を、全体にわたって繊維補強材が均一に分散した均一な密度を有する均質な発泡体が占めるようにする場合、電柱の中空部への繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の注入は、１回の注入によって中空部に充填する繊維補強材を含む発泡ウレタン樹脂の分量を、繊維補強材を含む発泡ウレタン樹脂が電柱の４ｍの高さまで膨張する分量とし、この分量の注入を２度行えばよい。繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の電柱の中空部への注入流量は、例えば少なくとも２ｋｇ／分とするのがよい。注入流量が少なすぎると、繊維補強材を含む発泡ウレタン樹脂の所定分量の充填が完了するまでに膨張し始めてしまうことで均質な発泡体が形成されない恐れがある。注入流量の上限に制限はないが、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートのそれぞれをミキシングヘッドに圧送するための注入機の一般的な性能などに鑑みれば、例えば６ｋｇ／分である。 Taking the example of a hollow concrete utility pole to be reinforced having a length of 12 m, injection of a mixed solution of polyol with a fiber reinforcing material and isocyanate with a fiber reinforcing material added into the hollow part is The amount of foaming urethane resin containing the fiber reinforcing material filled in the hollow expands to a height of at least 8 m from the lower end of the utility pole. The filling of the hollow part of the foamed urethane resin containing this amount of the fiber reinforcing material is not performed by one injection of the mixed solution of the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added. After the expansion of the foamed urethane resin containing the fiber reinforcement filled by the previous injection is completed, the next injection is carried out to expand the foamed urethane resin containing the filled fiber reinforcement. (i.e., stacking a subsequently formed foam on top of a previously formed foam). When the amount of urethane foam resin containing the fiber reinforcing material expands to a height of at least 8 m from the lower end of the utility pole at one time, the urethane foam containing the fiber reinforcing material rises to a height of at least 8 m from the lower end of the utility pole due to its own weight. It tends to form a non-homogeneous foam with lower density from bottom to top, with fiber reinforcements concentrated at the bottom. Fiber reinforcement is added in order to fill the hollow space from the lower end of the utility pole to a height of at least 8 m with a homogenous foam of uniform density with the fiber reinforcement uniformly distributed throughout. The amount of the foamed urethane resin containing the fiber reinforcement that fills the hollow portion by one injection of the mixed solution of the polyol and the isocyanate to which the fiber reinforcement is added is the standard density of the above-mentioned foam of 50 to 300 kg / m 3 . In the case of foamed urethane resin, the amount should be enough to expand to a height of 3 to 5 m (approximately 15 to 35 kg, depending on the diameter of the utility pole), and this amount should be injected multiple times. The amount of foamed urethane resin containing the fiber reinforcing material filled in the hollow part by one injection of the mixed solution of the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added is expanded to a height of less than 3 m of the utility pole. As a result, the number of times of injection increases, and there is a risk that the construction efficiency will deteriorate. For example, if the hollow space from the bottom end of a 12 m long utility pole to a height of 8 m is to be occupied by a homogeneous foam with a uniform density in which the fiber reinforcement is evenly distributed throughout, the utility pole Injection of the mixed solution of polyol with fiber reinforcement and isocyanate with fiber reinforcement into the hollow part of the fiber The amount of foamed urethane resin containing the reinforcing material should be such that it expands to a height of 4 m on the utility pole, and this amount may be injected twice. The flow rate of the mixture of the polyol containing the fiber reinforcement and the isocyanate containing the fiber reinforcement into the hollow portion of the utility pole is preferably at least 2 kg/min, for example. If the injection flow rate is too low, there is a risk that the foam will begin to expand before the predetermined amount of foamed urethane resin containing the fiber reinforcing material is completely filled, resulting in an inhomogeneous foam. There is no upper limit to the injection flow rate, but in view of the general performance of injectors for pumping each of the fiber-reinforced polyol and the fiber-reinforced isocyanate to the mixing head, for example, 6 kg/ minutes.
長さが１２ｍの電柱の中空部への繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の１回の注入を、充填された繊維補強材を含む発泡ウレタン樹脂が電柱の４ｍの高さまで膨張する分量とし、この分量の注入を２度行うことで、電柱の下端部から８ｍの高さまでの中空部の空間を、全体にわたって繊維補強材が均一に分散した均一な密度を有する均質な発泡体が占めるようにするための施工プロセスの一例を、図２を用いて説明する。 A single injection of a mixed solution of polyol with fiber reinforcement and isocyanate with fiber reinforcement added into the hollow part of a utility pole with a length of 12 m was performed, and the urethane foam resin containing the filled fiber reinforcement was injected into the utility pole. By setting the amount to expand to a height of 4m and injecting this amount twice, the hollow space from the lower end of the utility pole to the height of 8m is filled with a uniform density in which the fiber reinforcing material is evenly dispersed throughout. An example of a construction process for occupying a homogeneous foam having a structure will be described with reference to FIG. 2 .
図２において、孔１は、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の１度目の注入孔であり、孔径は例えば２０～３０ｍｍである。孔１を設けた位置は、電柱の下端部から３ｍの高さであって、図略のステップ取付穴が設けられている縦のライン上である（このライン上には削孔に干渉する鉄筋が存在しないので削孔を行うにあたって鉄筋の存在箇所を確認する必要がない）。電柱は、長さが１５ｍ以下の場合は長さの１／６以上、長さが１５ｍを超える場合は２．５ｍ以上を地中に根入れすることが定められており、図２に示す電柱では根入れ深さを２ｍとしているので、電柱の下端部から３ｍの高さは、地際から１ｍの高さである。孔１を設ける高さは、地面を掘り起こして設ける必要がなく、また、高所作業車の作業台から設ける必要がない、地際から２ｍまでの高さがよい。繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の孔１からの注入は、図１に示したミキシングヘッドに接続された注入ホースの先端を、孔１に差し込み、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液を吐出させることで行えばよい。繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の所定分量の注入が完了した後は、充填された繊維補強材を含む発泡ウレタン樹脂の膨張が孔１から外部に起こらないようにするため、養生テープを貼って孔１を塞ぐのがよい。繊維補強材を含む発泡ウレタン樹脂の膨張が完了すれば、養生テープを剥がし、孔１からはみ出している発泡体があれば削り落とした後、孔１をセメントで埋めて補修することで、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の孔１からの注入による一連の工程を終了するのがよい。 In FIG. 2, a hole 1 is a first injection hole for a mixed liquid of a polyol to which a fiber reinforcing material is added and an isocyanate to which a fiber reinforcing material is added, and the hole diameter is, for example, 20 to 30 mm. The hole 1 is located at a height of 3 m from the lower end of the utility pole, and is on a vertical line where a step mounting hole (not shown) is provided (on this line there is a reinforcing bar that interferes with drilling). There is no rebar, so there is no need to check the location of the rebar when drilling). If the length of a utility pole is 15m or less, it is stipulated that it should be embedded 1/6 or more of the length, and if the length exceeds 15m, it should be embedded 2.5m or more into the ground. Since the penetration depth is 2m, the height of 3m from the lower end of the utility pole is 1m from the ground. The height at which the hole 1 is provided is preferably a height of up to 2 m from the ground so that there is no need to dig up the ground and provide it from the workbench of the aerial work platform. Injection of the mixed liquid of the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added from the hole 1 is performed by inserting the tip of the injection hose connected to the mixing head shown in FIG. It may be carried out by discharging a mixture of polyol to which the material is added and isocyanate to which the fiber reinforcing material is added. After the injection of a predetermined amount of the mixed liquid of the polyol containing the fiber reinforcing material and the isocyanate containing the fiber reinforcing material is completed, expansion of the filled urethane foam containing the fiber reinforcing material does not occur outside from the hole 1. In order to prevent this, it is recommended to cover the hole 1 with a masking tape. When expansion of the foamed urethane resin containing the fiber reinforcing material is completed, the curing tape is peeled off, and if there is a foam protruding from the hole 1, it is scraped off, and then the hole 1 is filled with cement for repair, thereby reinforcing the fiber. The sequence of steps is preferably terminated by injecting a mixture of polyol to which the material is added and isocyanate to which the fiber reinforcement is added through the holes 1 .
図２において、孔２は、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の２度目の注入孔であり、孔径は孔１の孔径と同じ例えば２０～３０ｍｍであって、孔１を設ける時にあわせて設けたものである。孔２を設けた位置は、電柱の下端部から７ｍの高さ（地際から５ｍの高さ）であって、図略のステップ取付穴が設けられている縦のライン上である。繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の孔２からの注入を、孔１からの注入によって充填された繊維補強材を含む発泡ウレタン樹脂の膨張が完了してから行うと、電柱の下端部から４ｍの高さまでの中空部の空間はすでに均質な発泡体が占めている。従って、孔２を設けた高さは、繊維補強材を含む発泡ウレタン樹脂が膨張する高さ（４ｍ）の３／４の高さである（孔１と同じ）。孔２を設ける高さを、繊維補強材を含む発泡ウレタン樹脂が膨張する高さの１／３の高さよりも高くすることで、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の所定分量の注入が完了するまでに、充填された繊維補強材を含む発泡ウレタン樹脂が孔２の高さに到達してしまい、孔２から漏れ出してしまうことを避けることができる。繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の孔２からの注入の方法、所定分量の注入が完了した後の孔２の処置の方法は、孔１についての方法と同じでよい。孔２の設置、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の孔２からの注入、所定分量の注入が完了した後の孔２の処置は、高所作業車の作業台から行えばよい。 In FIG. 2, hole 2 is a second injection hole for a mixed liquid of polyol with added fiber reinforcement and isocyanate with added fiber reinforcement, and the hole diameter is the same as that of hole 1, for example 20 to 30 mm. , are provided at the same time as the holes 1 are provided. The hole 2 is provided at a height of 7 m from the lower end of the utility pole (a height of 5 m from the ground) on a vertical line provided with a step mounting hole (not shown). After the expansion of the foamed urethane resin containing the fiber reinforcing material filled by the injection from the hole 2 of the mixed solution of the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added is completed. When done, the hollow space from the lower end of the utility pole to a height of 4 m is already occupied by homogeneous foam. Therefore, the height at which the hole 2 is provided is 3/4 of the height (4 m) at which the foamed urethane resin containing the fiber reinforcing material expands (same as the hole 1). By setting the height of the holes 2 to be higher than 1/3 of the height at which the foamed urethane resin containing the fiber reinforcing material expands, the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added are mixed. It is possible to prevent the foamed urethane resin containing the filled fiber reinforcing material from reaching the height of the hole 2 and leaking out from the hole 2 before the injection of the predetermined amount of the mixed liquid is completed. The method of injecting the mixed liquid of the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added from the hole 2 and the method of treating the hole 2 after the injection of the predetermined amount is completed are the same as the method for the hole 1. can be the same. The installation of the hole 2, the injection of the mixed liquid of the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added from the hole 2, and the treatment of the hole 2 after the injection of the predetermined amount is completed, You can do it from the workbench.
図２において、孔３は、孔２からの繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の注入の際に繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液とともに電柱の中空部に流入する空気の排気孔であり、孔径は例えば１０～２０ｍｍであって、孔１を設ける時にあわせて設けたものである。孔３を設けた位置は、電柱の上端部から２ｍ低い高さ（地際から８ｍの高さ）であって（電柱の上端部から１～３ｍ低い高さに設けるのがよい）、図略のステップ取付穴が設けられている縦のライン上である。孔１からの繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の注入の際に繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液とともに電柱の中空部に流入する空気は、孔２から排気されることができるが、孔２からの繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の注入の際に繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液とともに電柱の中空部に流入する空気は、孔３がなければ排気されることができず、繊維補強材を含む発泡ウレタン樹脂が膨張するにつれて中空部の空間の圧力が高まり、この圧力によって電柱の先端を封止しているキャップ（ポールキャップ）が吹き飛んでしまうといった事態を引き起こす恐れがある。孔３は、孔２から充填された繊維補強材を含む発泡ウレタン樹脂の膨張が完了した後、セメントで埋めて補修するのがよい。孔３の設置、孔２からの繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の注入によって充填された繊維補強材を含む発泡ウレタン樹脂の膨張が完了した後の孔３の処置は、高所作業車の作業台から行えばよい。 In FIG. 2, the hole 3 is filled with the polyol added with the fiber reinforcing material and the isocyanate added with the fiber reinforcing material when the mixed liquid of the polyol added with the fiber reinforcing material and the isocyanate added with the fiber reinforcing material is injected from the hole 2. It is an exhaust hole for the air that flows into the hollow part of the utility pole together with the mixed solution of (1). The position where the hole 3 is provided is 2 m below the top of the utility pole (8 m above the ground) (preferably at a height of 1 to 3 m below the top of the utility pole), not shown. It is on the vertical line where the step mounting holes are provided. When the mixed solution of the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added is injected from the hole 1, the hollow part of the utility pole is filled with the mixed solution of the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added. Although the air flowing into the can be exhausted through hole 2, the fiber reinforcement added during the injection of the mixture of fiber reinforcement added polyol and fiber reinforcement added isocyanate from hole 2 The air that flows into the hollow part of the utility pole together with the mixture of polyol and isocyanate added with the fiber reinforcement cannot be exhausted without the holes 3, and the hollow part expands as the foamed urethane resin containing the fiber reinforcement expands. The pressure in the space between the poles increases, and this pressure may cause the cap (pole cap) that seals the tip of the utility pole to blow off. The hole 3 is preferably repaired by filling with cement after the expansion of the urethane foam resin containing the fiber reinforcing material filled from the hole 2 is completed. Hole 3 after completion of the expansion of the urethane foam containing the fiber reinforcement filled by the placement of the hole 3 and the injection of the mixed liquid of the polyol with the fiber reinforcement and the isocyanate with the fiber reinforcement added from the hole 2. The above procedure should be performed from the workbench of the aerial work platform.
なお、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液を、図１に示した注入ホースを接続したミキシングヘッドを用いて電柱の中空部に注入する場合、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートを混合し、両者の混合液を吐出させるための空気流の圧力は、例えば少なくとも０．０５ＭＰａとするのがよいことは前述の通りであるが、この圧力が高すぎると、孔１から繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液を注入した際、電柱の中空部において下方から上方に向かう強い空気流が発生し、空気流を構成する空気が孔２や孔３から勢いよく排気されるとともに、充填された繊維補強材を含む発泡ウレタン樹脂までもが空気流に乗って孔２や孔３から噴出する現象が起こる恐れがあり、孔２から繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液を注入した際にも同様に、充填された繊維補強材を含む発泡ウレタン樹脂が孔３から噴出する現象が起こる恐れがある。従って、こうした現象を避けるため、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートを混合し、両者の混合液を吐出させるための空気流の圧力は、上限を例えば０．１５ＭＰａとするのがよい。 In addition, when injecting a mixed solution of polyol to which a fiber reinforcing material is added and isocyanate to which a fiber reinforcing material is added into a hollow part of a utility pole using a mixing head connected to an injection hose shown in FIG. As described above, the pressure of the air flow for mixing the added polyol and the isocyanate to which the fiber reinforcing material is added and for discharging the mixture of the two is preferably at least 0.05 MPa, for example. If the pressure is too high, when a mixed solution of polyol with fiber reinforcement added and isocyanate with fiber reinforcement added is injected from the hole 1, a strong air flow is generated from the bottom to the top in the hollow part of the utility pole. There is a risk that the air that constitutes the flow will be vigorously exhausted from the holes 2 and 3, and that even the foamed urethane resin containing the filled fiber reinforcing material will be blown out from the holes 2 and 3 along with the air flow. Similarly, when a mixed liquid of polyol to which a fiber reinforcing material is added and isocyanate to which a fiber reinforcing material is added is injected from the hole 2, the foamed urethane resin containing the filled fiber reinforcing material is ejected from the hole 3. phenomenon may occur. Therefore, in order to avoid such a phenomenon, the upper limit of the pressure of the air flow for mixing the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added and discharging the mixed liquid of both is set to 0.15 MPa. It's good.
また、孔１を設けた高さや孔２を設けた高さよりも例えば２５～７５ｃｍ高い高さに、孔１や孔２からの繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の注入によって中空部に充填された繊維補強材を含む発泡ウレタン樹脂の様子を内視鏡を用いて調べるための確認孔を設けてもよい。 In addition, the polyol added with the fiber reinforcing material from the holes 1 and 2 and the isocyanate added with the fiber reinforcing material are mixed at a height, for example, 25 to 75 cm higher than the height at which the hole 1 is provided and the height at which the hole 2 is provided. A confirmation hole may be provided for checking the state of the foamed urethane resin containing the fiber reinforcing material filled in the hollow portion by injecting the liquid using an endoscope.
以上においては、長さが１２ｍの中空状のコンクリート製電柱を補強する場合を例にとって説明したが、長さが異なる電柱であっても、繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の１回の注入によって中空部に充填する繊維補強材を含む発泡ウレタン樹脂の分量や、この分量に応じて必要な注入孔の個数と設ける位置などを適切に設定することで、電柱を補強することができる。 In the above, the case of reinforcing a hollow concrete utility pole with a length of 12 m was explained as an example. By appropriately setting the amount of foamed urethane resin containing fiber reinforcing material to be filled in the hollow part by one injection of the isocyanate mixed solution, and the number and position of injection holes required according to this amount, Can reinforce poles.
例えば、長さが９ｍの中空状のコンクリート製電柱を、その中空部に前述した発泡体の標準密度が５０～３００ｋｇ／ｍ３となる発泡ウレタン樹脂を充填して膨張させることで補強する場合、中空部への繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の注入を２回に小分けして行い、１回の注入を、充填された繊維補強材を含む発泡ウレタン樹脂が電柱の３ｍの高さまで膨張する分量とし、この分量の注入を２度行うことで、電柱の下端部から６ｍの高さまでの中空部の空間を、全体にわたって繊維補強材が均一に分散した均一な密度を有する均質な発泡体が占めるようにすればよい。１度目の注入孔は、例えば、電柱の下端部から３ｍの高さ（根入れ深さを１．５ｍとすると地際から１．５ｍの高さ）であって、ステップ取付穴が設けられている縦のライン上に設ければよい。２度目の注入孔は、例えば、電柱の下端部から６ｍの高さであって、ステップ取付穴が設けられている縦のライン上に設ければよい。排気孔は、例えば、電柱の上端部から２ｍ低い高さであって、ステップ取付穴が設けられている縦のライン上に設ければよい。 For example, when a hollow concrete utility pole with a length of 9 m is reinforced by filling the hollow with the above-described foamed urethane resin having a standard density of 50 to 300 kg/m 3 and expanding it, A mixed liquid of polyol with a fiber reinforcing material added and isocyanate with a fiber reinforcing material added is injected into the hollow portion in two small portions, and one injection is performed with the urethane foam resin containing the filled fiber reinforcing material. is the amount that expands up to a height of 3 m of the utility pole, and by injecting this amount twice, the hollow space from the lower end of the utility pole to a height of 6 m is filled with a uniform fiber reinforcement that is evenly distributed throughout the entire space. It should be occupied by a homogenous foam with a uniform density. The first injection hole is, for example, a height of 3 m from the lower end of the utility pole (a height of 1.5 m from the ground when the penetration depth is 1.5 m), and a step mounting hole is provided. should be provided on the vertical line where the The second injection hole may be provided, for example, at a height of 6 m from the lower end of the utility pole and on the vertical line where the step mounting holes are provided. The exhaust hole may be provided, for example, at a height 2 m lower than the upper end of the utility pole and on the vertical line where the step mounting hole is provided.
例えば、長さが１５ｍの中空状のコンクリート製電柱を、その中空部に前述した発泡体の標準密度が５０～３００ｋｇ／ｍ３となる発泡ウレタン樹脂を充填して膨張させることで補強する場合、中空部への繊維補強材を添加したポリオールと繊維補強材を添加したイソシアネートの混合液の注入を３回に小分けして行い、１回の注入を、１度目の注入においては充填された繊維補強材を含む発泡ウレタン樹脂が電柱の４ｍの高さまで膨張する分量とし、２度目の注入と３度目の注入においては充填された繊維補強材を含む発泡ウレタン樹脂が電柱の３ｍの高さまで膨張する分量とすることで、電柱の下端部から１０ｍの高さまでの中空部の空間を、全体にわたって繊維補強材が均一に分散した均一な密度を有する均質な発泡体が占めるようにすればよい。１度目の注入孔は、例えば、電柱の下端部から４ｍの高さ（根入れ深さを２．５ｍとすると地際から１．５ｍの高さ）であって、ステップ取付穴が設けられている縦のライン上に設ければよい。２度目の注入孔は、例えば、電柱の下端部から７ｍの高さであって、ステップ取付穴が設けられている縦のライン上に設ければよい。３度目の注入孔は、例えば、電柱の下端部から１０ｍの高さであって、ステップ取付穴が設けられている縦のライン上に設ければよい。排気孔は、例えば、電柱の上端部から２ｍ低い高さであって、ステップ取付穴が設けられている縦のライン上に設ければよい。 For example, when reinforcing a hollow concrete utility pole with a length of 15 m by filling and expanding the above-mentioned foamed urethane resin having a standard density of 50 to 300 kg/m 3 in the hollow part, The mixed solution of the polyol to which the fiber reinforcing material is added and the isocyanate to which the fiber reinforcing material is added is injected into the hollow part in three subdivided times, and one injection is performed, and the first injection is filled with fiber reinforcement. The amount of urethane foam resin containing the material expands to a height of 4m of the utility pole, and in the second injection and the third injection, the amount of expansion of the urethane foam resin containing the filled fiber reinforcing material expands to a height of 3m of the utility pole. By doing so, the hollow space from the lower end of the utility pole to a height of 10 m should be occupied by a homogeneous foam having a uniform density in which the fiber reinforcing material is evenly distributed throughout. The first injection hole is, for example, a height of 4 m from the lower end of the utility pole (a height of 1.5 m from the ground when the penetration depth is 2.5 m), and a step mounting hole is provided. should be provided on the vertical line where the The second injection hole may be provided, for example, at a height of 7 m from the lower end of the utility pole and on the vertical line where the step mounting holes are provided. The third injection hole may be provided, for example, at a height of 10 m from the lower end of the utility pole and on the vertical line where the step mounting holes are provided. The exhaust hole may be provided, for example, at a height 2 m lower than the upper end of the utility pole and on the vertical line where the step mounting hole is provided.
本発明は、スプレーガンを用いることなく、中空状のコンクリート製電柱の中空部に繊維補強材を含む発泡ウレタン樹脂を充填して膨張させることによる電柱の補強方法を提供することができる点において産業上の利用可能性を有する。 INDUSTRIAL APPLICABILITY The present invention is capable of providing a method for reinforcing a utility pole by filling the hollow portion of a hollow concrete utility pole with a foamed urethane resin containing a fiber reinforcing material and expanding it without using a spray gun. have availability on
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2022013415A Pending JP2023111529A (en) | 2022-01-31 | 2022-01-31 | Reinforcement method for utility pole |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2023111529A (en) |
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2022
- 2022-01-31 JP JP2022013415A patent/JP2023111529A/en active Pending
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