JP3762808B2 - Repair method of the top of steel tower foundation concrete - Google Patents

Description

【００１８】
アクリル系樹脂でメタクリル酸メチルは、エポキシ樹脂やビニールエステルに比較して、強靭で、耐候性、耐酸性及び耐水性に優れ、屋外での防食材料としては最良のものである。そのため、基礎コンクリートの鉄塔部材の腐食部近傍必要最少限の基礎コンクリート天端部をはつり取るだけでよく、必要材料を最少限に押さえられることから、労力の削減、産業廃棄物の削減ができる効果がある。
【００１９】
また、重合形態がラジカル反応で硬化するため、１〜２時間で実用強度に達する速硬化性で、エポキシ樹脂では２、３日かかった補修工事が半日で完了させることができ、工期の短縮が図れる効果を奏する。
開始剤の過酸化ベンゾイルの添加量を増やすことにより、−５℃の気温まで施工が可能になり、エポキシ樹脂に比較して施工条件が緩和される利点を有している。
【００２０】
シリコーンシーリング材は、優れた弾性と接着性、耐候性、耐水性を有しているため、屋外でも様々に使用されている。その優れた特性をより良く発揮させるために、鉄塔部材に間仕切材を用いてシリコーンシーリング材をより厚く充填、塗布し、防水性を高め、補修部分は強靭なアクリル樹脂モルタルで覆っているため、地震や風勢等によって鉄塔が振動してクラックが発生することがあるが、シリコーンシーリング材の弾性で、鉄塔の振動による応力を緩和し、クラックの発生を防止する効果を果している。
【００２１】
シリコーンシーリング材に無酸型を使用しているため、鉄塔部材の金属部分に再び腐食の発生するのを防止している。
【００２２】
【発明の効果】
以上説明したように、請求項１記載の発明によれば、はつり部分にアクリル樹脂モルタルを打設することとしたので、アクリル樹脂モルタルの持つ速硬化性により工期の短縮が図れる。
また、アクリル系樹脂を使用するため、耐候性、耐酸性、耐水性に優れている。さらに、シリコーンシーリング材を充填，塗布するため、耐候性、耐水性に優れている。
【００２３】
請求項２記載の発明によれば、間仕切材撤去跡にシリコーンシーリング材を充填するので、鉄塔の補修部分の防水性を高めると共に、シリコーンシーリング材の弾性により、鉄塔の振動による応力を緩和することができる。
【図面の簡単な説明】
【図１】本発明の補修工法の補修部分の補修完了後の断面図である。
【図２】本発明の補修工法のはつり部の断面図である。
【図３】本発明の補修工法のアクリル樹脂モルタルを打設した断面図である。
【図４】通常の鉄塔の基礎部分の構成断面図である。
【図５】従来の補修工法の構成断面図である。
【符号の説明】
１ 鉄塔部材
２ 基礎コンクリート
３ 地盤
４ 発錆部
５ はつり部
６ 天端面
７ 掘削
８ 第一プライマー層
９ 第二プライマー層
１０ アクリル樹脂モルタル
１１ トップコート樹脂
１２ シリコーンシーリング材
１３ 間仕切材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for repairing corrosion or the like generated near the contact portion between a steel tower and a foundation concrete top end.
[0002]
[Prior art]
Usually, the structure of the foundation part of a steel tower such as a transmission line is constructed by excavating the ground 3 and standing the tower member 1 in the excavation hole as shown in FIG. It is embedded up to six. As the foundation concrete 2 of the constructed steel tower ages, cracks are generated due to a gap generated between the steel tower member 1 due to drying and shrinkage during concrete construction, or vibration of the steel tower due to earthquakes, winds, and the like. Moreover, a clearance gap will generate | occur | produce between the steel tower members 1 by the weakening by the secular change of concrete, etc. The rainwater enters the cracks near the contact point between the top end surface 6 of the foundation concrete 2 and the tower member 1, causing a typical crevice corrosion rusting part 4 of the tower member 1, and the durability of the tower It will have a serious impact on.
[0003]
In the conventional repair method, as shown in the cross-sectional configuration diagram of FIG. 5, the ground 3 around the foundation concrete 2 is excavated 7, most of the suspension portions 5 above the foundation concrete 2 are removed, and the steel tower member 1 is rusted. The part 4 is repaired, concrete is newly placed, and the top end face 6 is finished with mortar. Alternatively, a repairing method in which an epoxy resin mortar obtained by adding an aggregate to an epoxy resin has been adopted.
[0004]
[Problems to be solved by the invention]
The conventional method of repairing by placing new concrete is to repair the cracks in the steel tower member and concrete with the same material, only to temporarily prevent the corrosion phenomenon. The recurrence of the gaps and cracks cannot be prevented, and corrosion of the steel tower member will occur over time due to the same cause again. In this method, the ground is dug deeply, most of the foundation concrete is removed, new concrete is cast, and curing takes several days to harden, which takes a long construction period. In addition, there are problems such as industrial waste due to the lifting of foundation concrete, formwork installation and removal, and cost increase due to an increase in the amount of materials used.
[0005]
In addition, in the method of repairing by placing an epoxy resin mortar, the epoxy resin is an excellent material in terms of adhesion, strength, shrinkage, etc., but the epoxy resin has a slow curing rate due to thermosetting, It is extremely slow, especially at low temperatures, and sometimes does not harden outdoors in winter. Therefore, in order to speed up curing, a heating device may be installed, but it is difficult to install these devices in mountainous areas, etc., and even if installed, it takes time to transport the device, and this repair method is adopted. It has the disadvantages that it is difficult and the repair costs are expensive. Actually, when repairing with epoxy resin, it will take 2-3 days for normal application, primer application, epoxy resin mortar placement, and coating treatment, while rainproofing of repaired parts, etc. Protective measures must be taken so as not to touch water, which is not practical.
[0006]
In view of such circumstances, the present invention uses a resin mortar made of a fast-curing acrylic resin that has excellent anticorrosion and waterproof properties, mechanical strength, and can shorten the work period. The repair method of a part is provided and it is going to solve the problem of the said conventional repair method.
[0007]
[Means for Solving the Problems]
In the repair of the base concrete top end of the steel tower, the present invention hangs the base concrete top end, applies a zinc-based anticorrosive protective material to the rusting part of the steel tower member, and applies the acrylic resin to the remaining upper surface of the base concrete. Apply a mixture with initiator added, place acrylic resin mortar with initiator and aggregate added to acrylic resin on the suspension part, silicone sealant at and near the contact point between the tower and the top of acrylic resin mortar It is characterized by being configured to fill and apply.
[0008]
In addition, before placing acrylic resin mortar, the partition material of foaming material is installed in the repaired part of the steel tower, acrylic resin mortar is cast, removed after curing, and the silicone sealant is filled in the removal trace To do.
In repairing the top concrete end of the tower tower, lift the foundation concrete top to the position where the corrosion of the tower has occurred, and apply zinc-based rust protection material to the rusted part of the tower member. In order to achieve adhesion with acrylic resin, foundation concrete is coated with a mixture of acrylic resin and initiator added to the suspension surface, and acrylic resin mortar with initiator and aggregate added to acrylic resin is placed. Reinforce the steel tower. Before placing the acrylic resin mortar, a partition material made of a foam material is temporarily placed on the outer periphery of the corroded portion of the steel tower, and the acrylic resin mortar is placed and removed after curing. A silicone sealing material is thickly filled and applied to the contact point between the steel tower member and the top of the acrylic resin mortar and the vicinity of the partition material removal trace, thereby constituting a waterproof and flexible repair.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
1 is a cross-sectional view after completion of repair of the repair method of the present invention, FIG. 2 is a cross-sectional view showing a suspended portion of the repair method, and FIG. 3 is a cross-sectional view in which acrylic resin mortar of the repair method is placed. .
The embodiment will be described with reference to the drawings. The top end of the foundation concrete 2 covering the tower member 1 is suspended up to the position where corrosion of the tower member 1 occurs (shown as the suspended portion 5 in FIG. 2). .
[0010]
The rusting part 4 of the steel tower member 1 is subjected to polishing treatment, and the remaining upper surface of the basic concrete 2 is cleaned.
A zinc-based rust preventive protective material is applied to the rusting portion 4 of the steel tower member 1 as a rust preventive protective material. The zinc-based rust preventive protective material does not hinder the adhesion with the acrylic resin mortar. For example, Zinc Rich Pando 614A (manufactured by Three Bond Co., Ltd.) is applied.
[0011]
Next, a mixture obtained by adding 1 to 10% benzoyl peroxide (BPO), which is an initiator for causing radical polymerization to methyl methacrylate (MMA) monomer of an acrylic resin, on the surface of the basic concrete 2, The first primer layer 8 is formed by adjusting the viscosity to a low viscosity of 10 to 200 cP in order to obtain adhesiveness with the acrylic resin, and applying it so as to sufficiently permeate the details.
[0012]
After the first primer layer 8 is cured, a homogeneous mixture is applied to the surface of the first primer layer 8 to form the second primer layer 9.
After the second primer layer 9 is cured, a 10 mm square foamed polyethylene partition material 13 is attached to the surface of the rusting portion 4 from the position of the top 0-15 mm of the rusting portion 4 of the tower member 1 (see FIG. 3).
[0013]
Acrylic resin mortar 10 in which 1-15% benzoyl peroxide and aggregates such as cinnabar and pebbles are added to methyl methacrylate to cover the rusted portion 4 and repair the top end.
After the acrylic resin mortar 10 is cured, the partition material 13 made of foamed polyethylene is removed.
[0014]
On the surface of the acrylic resin mortar 10, a top coat resin 11 of a mixture obtained by adding 1 to 10% benzoyl peroxide and a toner to methyl methacrylate monomer is applied. After the top coat resin 11 is cured, it is a non-acidic RTV (room temperature curable) silicone sealant 12 on the finished surface of the acrylic resin mortar 10, the trace of the partition member 13 removed, and the surface of the steel tower member 1. For example, ThreeBond 5211KD (manufactured by ThreeBond Co., Ltd.) is filled and applied with a cartrich gun.
[0015]
Examples of the acrylic resin of the acrylic resin mortar include alkyl acrylates such as methyl acrylate, ethyl acrylate, and ethyl methacrylate, alkyl methacrylates, and copolymerized oligomers thereof in addition to the above-described embodiments, and are usually monomers. A polymerization inhibitor and catalyst are included. The polymerization inhibitor and the catalyst are added for storage stability and room temperature polymerization. In addition to the above embodiment, azobisisobutyronitrile (AIBN), cumene hydroperoxide, dicumyl peroxide and the like are used as the initiator, and the addition amount is 1 depending on the temperature and the coating amount. ~ 15% added. As the silicone sealant, an acid-free RTV (room temperature curable) silicone such as a deoxime type other than the deacetic acid type, a deacetone type, and a dealcohol type is used.
[0016]
A comparison table regarding the minimum construction temperature, curing time, strength, water absorption, weather resistance, and physical properties of methyl methacrylate and epoxy resin, cement, and concrete is shown below.
[0017]
[Table 1]

[0018]
Methyl methacrylate, an acrylic resin, is tougher and better in weather resistance, acid resistance and water resistance than epoxy resins and vinyl esters, and is the best outdoor anticorrosion material. Therefore, it is only necessary to scrape the minimum necessary basic concrete top end near the corroded part of the steel tower member of the basic concrete, and the necessary materials can be kept to the minimum, which can reduce labor and industrial waste. There is.
[0019]
In addition, since the polymerized form is cured by radical reaction, it is fast-curing that reaches practical strength in 1 to 2 hours. With epoxy resin, repair work that took 2 or 3 days can be completed in half a day, and the construction period can be shortened. There is an effect that can be achieved.
By increasing the amount of benzoyl peroxide added as an initiator, the construction can be performed up to a temperature of −5 ° C., and the construction conditions are reduced compared to the epoxy resin.
[0020]
Silicone sealants have excellent elasticity, adhesion, weather resistance, and water resistance, and are therefore used in various ways outdoors. In order to better demonstrate its excellent characteristics, the steel sealant is filled and applied thicker using a partition material on the steel tower member to improve waterproofness, and the repaired part is covered with tough acrylic resin mortar, The steel tower may vibrate due to earthquakes, winds, etc., and cracks may occur. However, the elasticity of the silicone sealing material reduces the stress caused by the vibration of the steel tower and prevents cracks from occurring.
[0021]
Since the non-acidic type is used for the silicone sealant, corrosion is prevented from occurring again in the metal portion of the steel tower member.
[0022]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the acrylic resin mortar is placed on the suspended portion, the work period can be shortened due to the rapid curability of the acrylic resin mortar.
Moreover, since acrylic resin is used, it is excellent in weather resistance, acid resistance, and water resistance. Furthermore, since the silicone sealing material is filled and applied, it is excellent in weather resistance and water resistance.
[0023]
According to the invention described in claim 2, since the silicone sealant is filled in the partition material removal trace, the waterproof property of the repaired portion of the steel tower is enhanced, and the stress caused by vibration of the steel tower is relieved by the elasticity of the silicone sealant. Can do.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a repaired portion of the repairing method according to the present invention after repair is completed.
FIG. 2 is a cross-sectional view of a suspended portion of the repair method according to the present invention.
FIG. 3 is a cross-sectional view in which an acrylic resin mortar according to the repair method of the present invention is placed.
FIG. 4 is a structural cross-sectional view of a basic part of a normal steel tower.
FIG. 5 is a cross-sectional view of a conventional repair method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Steel tower member 2 Foundation concrete 3 Ground 4 Rust part 5 Suspension part 6 Top face 7 Excavation 8 1st primer layer 9 2nd primer layer 10 Acrylic resin mortar 11 Top coat resin 12 Silicone sealing material 13 Partition material

Claims (2)

In repairing the top of the foundation concrete of the steel tower, hang the foundation concrete top, apply zinc-based anticorrosive protective material to the rusting part of the steel tower member, and add an initiator to the acrylic resin on the top of the remaining foundation concrete The acrylic resin mortar in which the initiator and aggregate are added to the acrylic resin is placed in the suspension part, and the silicone sealant is filled and applied at the contact point between the tower and the top of the acrylic resin mortar. A repair method for the top of the steel tower foundation concrete, characterized in that The steel tower according to claim 1, wherein before placing the acrylic resin mortar, a partition material of the foam material is installed at a repaired portion of the steel tower, removed after the acrylic resin mortar is placed and cured, and the silicone sealant is filled in the removed trace. Repair method for top edge of foundation concrete.

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