JP3981993B2 - Rust prevention agent for lightweight cellular concrete reinforced steel bars - Google Patents
Rust prevention agent for lightweight cellular concrete reinforced steel bars Download PDFInfo
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Description
【０００１】
【発明の属する技術分野】
この発明は主として水蒸気養生軽量気泡コンクリート（以下ＡＬＣという）の補強用鉄筋に塗布して、この鉄筋の錆の発生を防止する軽量気泡コンクリート補強鉄筋用防錆剤の組成に関するものである。
【０００２】
【従来の技術】
ＡＬＣを製造する場合には、先ず直径５〜１２ｍｍの鉄筋を金網状に整形した鉄筋マットや、細い鉄線の網状のメタルラスなどの補強用鉄筋に、防錆処理してから型枠にセットする。次にこの型枠内に、珪砂などの珪酸質原料と、ポルトランドセメントなどの石灰質原料に、水を加えて混練したスラリーに、アルミニウム粉などを添加したスラリーを注入して発泡させる。そして所望時間経過して半可塑性状態に硬化したら、前記型枠から半可塑性体を取り出して所望寸法に切断し、オートクレーブに装入して高温高圧で水蒸気養生する。その後必要に応じて表面を仕上げ加工して製品にしている。
【０００３】
このようにして製造されたＡＬＣは、約８０％の気孔を有するので、嵩比重が０．６程度と軽量であり、断熱性や耐久性、加工性にも優れているので、建築材料として広く使用されている。一方前記気泡を通じて外気中の水分や塩分が内部に侵入すると、埋設されている補強用鉄筋が腐食されやすい問題がある。そのため、この補強用鉄筋には前述のように防錆処理されているが、その方法は一般にスラリー状の防錆剤に補強鉄筋を浸漬させてから引上げ、乾燥させる工程を１〜２回繰り返して施工している。そのためこの防錆剤には、その防錆性能や作業性に関連して次のような特性が要求されている。
【０００４】
即ち▲１▼鉄筋の防錆性に優れていること。▲２▼種々な形状、寸法の鉄筋にも均一に付着し、且つこの被膜の付着力が高いこと。▲３▼適度な可撓性があり剥離し難いこと。▲４▼長時間防錆剤スラリーの粘性変化や、沈殿などが発生しないこと。▲５▼施工時に有害なガスや着火性のガスが発生しないこと。▲６▼経済的であることなどである。そして従来の防錆剤としては、１）センメントを主結合剤とするもの。２）アスファルトを主結合剤とするもの。３）樹脂または樹脂エマルジョン、或いはラテックスを主結合剤とするものがあった。
【０００５】
しかしいずれも一長一短があって前記すべての条件を満たす防錆剤はなかった。そこで本出願人は種々研究の結果、特公平１−３２３１０号及び特開昭６２−１６１８６９号公報に記載した防錆剤を発明し、実用上一応満足できる結果がえられた。しかしこの防錆剤では、ｐＨ調整用に消石灰を添加し、防錆施工後の被膜表面の平滑性を向上させるために石灰石粉を添加するが、これら石灰質の量が１０％以上になると、オートクレーブでの蒸気養生の際に、原料中の珪酸とアルカリ土類金属とが化学反応して非晶質の珪酸カルシウムが生成され、被膜の強度低下や吸水性の上昇などの悪影響がでる問題があった。
【０００６】
【発明が解決しようとする課題】
この発明は主としてＡＬＣ用の補強用鉄筋等に防錆被膜を形成した場合に、この鉄筋の防錆効果が長期にわたって安定して大きく、また作業性と経済性に優れた軽量気泡コンクリート補強鉄筋用防錆剤を提供するものである。
【０００７】
【課題を解決するための手段】
本発明の防錆剤の組成は、スチレン系樹脂の水性エマルジョンを固形分として５〜２５重量％と、アスファルトの水性エマルジョンを固形分として５〜１５重量％とからなる結合剤（ａ）と、珪酸塩を含有しないアルカリ土類の炭酸塩の無機質粉末を固形分として６０〜９０重量％（ｂ）とを主成分としたものである。またアルカリ土類の炭酸塩が石灰石であるものである。また前記スチレン系樹脂の水性エマルジョンは、スチレン結合量が６５〜７５重量％のハイスチレンＳＢＲの水性エマルジョン、又はスチレン結合量が５５〜６５重量％のＳＢＲの水性エマルジョンを、不飽和カルボン酸で変性硬化したスチレンブタジエン樹脂の水性エマルジョンとしたものである。更に無機質粉末に、５重量％以下の消石灰を添加したものである。
【０００８】
【発明の実施の形態】
本発明の防錆剤の組成は、スチレン系樹脂の水性エマルジョンを固形分として５〜２５重量％と、アスファルトの水性エマルジョンを固形分として５〜１５重量％とからなる結合剤（ａ）と、珪酸塩を含有しないアルカリ土類の炭酸塩の無機質粉末を固形分として６０〜９０重量％（ｂ）とを主成分としたので、オートクレーブでの蒸気養生の際に、珪酸塩とアルカリ土類金属とが化学反応して非晶質の化学的に不安定なゲル状の珪酸カルシウム化合物が生成されることがない。
【０００９】
本発明において珪酸塩とは珪酸および珪酸の塩類を示すものである。本発明ではアルカリ土類の炭酸塩の無機質粉末が結合剤中に分散し、鉄筋表面に該無機質粉末を骨材としたスチレン系樹脂とアスファルトとで結合された被膜を形成するものである。この被膜は化学的に安定であるから被膜の強度低下や吸水性の上昇などの悪影響を長期にわたって避けることができる。また該結合剤は水性エマルジョンなので有害なガスが発生することがない。
【００１０】
更に石灰石粉などの炭酸塩類の量が多いので、防錆被膜の可撓性と防錆性が向上するし、経済的である。またアルカリ土類の炭酸塩類としては、一般に天然石灰石が使用される。工業原料としての炭酸カルシウム粉末も差し支えなく使用できる。この石灰石には炭酸マグネシウムや炭酸バリウムなど非珪酸質の不純物が含有されていても問題ない。そしてスチレン系樹脂の水性エマルジョンを固形分として５〜２５重量％の結合剤とし、アスファルトの水性エマルジョンを固形分として５〜１５重量％とからなる結合剤としたのは、いずれも５重量％未満では、防錆性能が顕著に低下し、２５重量％を越えると、ＡＬＣとの付着力が低下し防錆性能が悪化するからであり、望ましくは前者は８〜１６重量％、後者は７〜１２重量％である。
【００１１】
なおスチレン系樹脂の水性エマルジョンとしては、ポリスチレン、スチレンブタジエン、スチレンアクリロニトリル、ポリブタジエンスチレン、アクリロニトリルブタジエンスチレンなどの水性エマルジョンを使用できるが、前記スチレン系樹脂の水性エマルジョンは、スチレン結合量が６５〜７５重量％であるかまたはスチレン結合量が５５〜７５重量％であって、一部を不飽和カルボン酸で変性硬化させたスチレンブタジエン樹脂の水性エマルジョンであることが望ましい。スチレン結合量が５５重量％未満では、防錆被膜が軟質で付着力が劣り、７６重量％以上では被膜が硬質で可撓性が劣るためである。また、不飽和カルボン酸は硬化作用のほかに可撓性も同時に付与できるので、上記スチレン結合量が６５〜７５重量％である場合でも少量を使用することが好ましい。
【００１２】
なお、スチレン結合量が５５重量％未満の場合でも不飽和カルボン酸などの二重結合を有する物質を適当量共重合させることによって、所望硬度の被膜を形成することができる。また前記無機質には、消石灰は必ずしも添加しなくてもよいが、５重量％以下の消石灰を添加すると防錆剤のｐＨや粘度の調整が可能で、防錆剤の被膜の付着性と防錆性能が向上できる。しかし消石灰の添加量が５重量％を越えると、防錆剤の粘度が顕著に上昇して防錆剤被膜の膜厚の調整が困難となったり、防錆剤がゲル化し易くなる弊害がでるので、望ましくは２〜４％である。更に前記無機質物質に、インヒビターを添加すれば防錆性能が向上できるし、カーボンファイバーなどの繊維を添加すれば、防錆被膜の亀裂を防止できる。その他、必要に応じて分散剤や消泡剤、酸化鉄、酸化チタンなどを添加してもよい。
【００１３】
【実施例】
以下本発明の一実施例を説明する。この防錆剤はスチレン結合量約７０重量％、ブタジエン約３０重量％を主成分とする固形分が４５重量％の、スチレンブタジエン樹脂の水性エマルジョン（武田薬品工業製商品名クロスレンＳＰＸ−１）を、固形分として３〜３０重量％と、固形分５５重量％の水性アスファルトエマルジョン（昭和シェル石油製商品名フリンコートＮＯ５）を固形分として３〜２０重量％とを結合剤（ａ）とし、石灰石粉末（菱光石灰製商品名ＣＸ）を６０〜８５重量％（ｂ）とし、更に外割りで添加物としては分散剤（花王製商品名マイテイー１５０Ｒ）を０．５重量％と、消泡剤（第一工業製薬製商品名アンチフロス）０．１重量％を添加し、これらの混合物に適量の水とｐＨ調整剤（試薬１級消石灰）を加えて３０分撹拌し、スラリー状の防錆剤を作成した。
【００１４】
また性能を比較するために使用した従来の防錆剤は次の１種類である。結合剤（ａ）としては前述と同様なスチレンブタジエン樹脂の水性エマルジョンを固形分として２０重量％と、水性アスファルトエマルジョンを固形分として７重量％使用し、無機質（ｂ）としては珪石粉末（東海工業製特粉）７０重量％と消石灰３重量％とし、他の分散剤や消泡剤は前例と同様である。
【００１５】
そして上記の各防錆剤に、直径５．５ｍｍの補強鉄筋を浸漬後８０℃で熱風乾燥する作業を繰り返して、平均厚さ２００μｍの防錆被膜を形成した。これらの補強鉄筋を型枠に固定して、以下通常の方法に従って比重０．５のＡＬＣを製造した。こうして製作されたＡＬＣから４×４×１６ｃｍの角柱の縦方向の中心に鉄筋が位置するように切断して１３種類の試料が作成した。
【００１６】
こうして得られた各試料の試験方法と、性能の判断基準は次の通りであり、試験結果は表１に示す。表中の試験番号１は従来の防錆剤を使用したものであり、試験番号２〜６はいずれも本発明の防錆剤を使用した実施例であるが、試験番号６の結合剤（Ａ）はスチレン結合量約５５重量％のＳＢＲの水性エマルジョンを、不飽和カルボン酸で変性硬化したスチレンブタジエン樹脂の水性エマルジョンを使用したものである。また試験番号７〜１２はいずれも比較例であるが、試験番号７〜１１は結合剤や石灰石の配合量が本発明の範囲外の例であり、試験番号１２及び１３はスチレン結合量が夫々約５５重量％と、８５％のハイスチレンＳＢＲの水性エマルジョンを使用した例である。
付着力；押し抜き法による最大荷重を鉄筋の表面積で除した値
○：２０ｋｇ／ｃｍ2 以上
△：１５〜２０ｋｇ／ｃｍ2
×：１５ｋｇ／ｃｍ2 未満
防錆性：ＪＩＳＡ５４１６に準ずるが、一層判別しやすいように、試験開始前と試験期間中は２日おきに試料を３％の食塩水に浸漬し、試験期間は２週間として発錆面積を測定した。
◎：０．５％未満
○：０．５〜２．０％
×：２．０％以上
可撓性
○：４５度折り曲げても亀裂が発生しない。
×：４５度折り曲げて亀裂が発生する。
ポットライフ：蓋付きの容器に防錆剤を入れ、密封状態で放置した場合と、毎日容器内の防錆剤の１０％を新品と入れ替えた場合の両者について、容器内の防錆剤の粘度の変化やゲル化、沈降状態を観察する。
○：１か月以上変化しないか、一部沈降しても撹拌すれば元に戻る。
×：１か月以内にゲル化したり、沈降物を撹拌しても元に戻らない。
【００１７】
【表１】
表１から明らかなように、従来の防錆剤を使用した試験番号１は、防錆性が劣っている。それに対し、試験番号２〜６の本発明の実施例では全ての性能が満たされている。特に試験番号２〜３の配合では最も優れた性能を示した。また、試験番号４の消石灰を配合しない場合は、他の例に比し付着性と防錆性がやや低下し、試験番号６の結合剤を代えた場合は、防錆性がやや低いが、いずれも実用性に問題はない。
【００１９】
比較例の試験番号７、８と９、１０は、ＡまたはＢの配合率が高過ぎたり低すぎるために、付着力と防錆性のいずれか又は両方が基準値に達せず、試験番号１１はＤの配合率が高すぎるため、作業性が悪化しポットライフと付着力に問題がある。更にスチレン結合量が夫々約５５重量％と、８５重量％のＳＢＲの水性エマルジョンを使用した例試験番号１２、１３でも付着力と可撓性に問題が出る。
【００２０】
【発明の効果】
以上詳細に説明したように、本発明の防錆剤は作業性や保存性に優れ、どんな形状、寸法の補強鉄筋にも防錆被膜を形成することができ、またこの防錆被膜は鉄筋への付着力が大きく、可撓性もあるので亀裂の発生がなく、優れた防錆性を得ることができる。そのため、沿岸部など塩害が発生しやすい地域でも鉄筋が腐食することがない。またこの防錆剤は、価格も比較的安く経済性にすぐれており、ＡＬＣの補強鉄筋のみならず、一般の鉄筋コンクリートの鉄筋の防錆にも使用することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a composition of a rust inhibitor for lightweight cellular concrete reinforced reinforcing bars, which is applied to reinforcing bars for steam-cured lightweight aerated concrete (hereinafter referred to as ALC) to prevent the rust of the reinforcing bars.
[0002]
[Prior art]
In the case of manufacturing ALC, first, a reinforcing bar such as a rebar mat in which a rebar having a diameter of 5 to 12 mm is shaped into a wire mesh or a reinforcing metal rebar such as a net-like metal lath of a thin iron wire is subjected to rust prevention treatment and then set on a mold. Next, a slurry obtained by adding aluminum powder or the like to a slurry obtained by adding water to a siliceous raw material such as silica sand and a calcareous raw material such as Portland cement is poured into the mold and foamed. Then, after the desired time has passed and the resin is cured to a semi-plastic state, the semi-plastic material is taken out from the mold, cut into a desired size, charged into an autoclave, and steam-cured at high temperature and high pressure. After that, the surface is finished as necessary to make a product.
[0003]
Since the ALC produced in this way has about 80% pores, its bulk specific gravity is as light as about 0.6, and it has excellent heat insulation, durability, and workability. in use. On the other hand, when moisture or salt in the outside air enters the inside through the bubbles, there is a problem that the reinforcing reinforcing bars embedded are easily corroded. Therefore, this reinforcing steel bar has been rust-proofed as described above, but the method is generally to repeat the process of pulling up and drying the reinforcing steel bar after immersing the reinforcing steel bar in a slurry-like anticorrosive agent once or twice. We are constructing. Therefore, this rust inhibitor is required to have the following characteristics in relation to its rust prevention performance and workability.
[0004]
That is, (1) The rust resistance of the reinforcing bar is excellent. (2) It adheres uniformly to reinforcing bars of various shapes and dimensions, and the adhesion of this coating is high. (3) It has moderate flexibility and is difficult to peel off. (4) No change in viscosity or precipitation of the rust inhibitor slurry for a long time. (5) No harmful gas or ignitable gas is generated during construction. (6) It is economical. And as a conventional rust preventive agent, 1) What uses a sentiment as a main binder. 2) Asphalt is the main binder. 3) Some resins have resin, resin emulsion, or latex as the main binder.
[0005]
However, all of them had advantages and disadvantages, and there was no rust inhibitor satisfying all the above conditions. Therefore, as a result of various studies, the present inventor has invented the rust preventives described in Japanese Patent Publication No. 1-332310 and Japanese Patent Laid-Open No. 62-161869, and has obtained satisfactory results for practical use. However, with this rust inhibitor, slaked lime is added for pH adjustment, and limestone powder is added to improve the smoothness of the coating surface after the rust prevention work. When the amount of these calcareous substances exceeds 10%, the autoclave During steam curing, there is a problem in that silicic acid and alkaline earth metal in the raw material react with each other to produce amorphous calcium silicate, resulting in adverse effects such as reduced coating strength and increased water absorption. It was.
[0006]
[Problems to be solved by the invention]
In the present invention, when a rust preventive coating is formed mainly on reinforcing bars for ALC, etc., the reinforcing effect of these reinforcing bars is stable and large over a long period of time, and for lightweight cellular concrete reinforced reinforcing bars excellent in workability and economy. A rust preventive is provided.
[0007]
[Means for Solving the Problems]
The composition of the rust inhibitor of the present invention comprises a binder (a) consisting of 5 to 25% by weight of an aqueous emulsion of a styrenic resin as a solid, and 5 to 15% by weight of an aqueous emulsion of asphalt as a solid. The main component is 60 to 90% by weight (b) of an inorganic powder of alkaline earth carbonate containing no silicate as a solid content. The alkaline earth carbonate is limestone. In addition, the aqueous emulsion of the styrene resin is modified with an unsaturated carboxylic acid, an aqueous emulsion of high styrene SBR having a styrene bond amount of 65 to 75% by weight, or an aqueous emulsion of SBR having a styrene bond amount of 55 to 65% by weight. This is an aqueous emulsion of a cured styrene butadiene resin. Further, 5% by weight or less of slaked lime is added to the inorganic powder.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The composition of the rust inhibitor of the present invention comprises a binder (a) consisting of 5 to 25% by weight of an aqueous emulsion of a styrenic resin as a solid, and 5 to 15% by weight of an aqueous emulsion of asphalt as a solid. The main component is 60 to 90% by weight (b) of an alkaline earth carbonate inorganic powder containing no silicate as a solid content. Therefore, during steam curing in an autoclave, silicate and alkaline earth metal are used. Does not produce an amorphous chemically unstable gel-like calcium silicate compound.
[0009]
In the present invention, the term “silicate” refers to silicic acid and silicic acid salts. In the present invention, an inorganic powder of alkaline earth carbonate is dispersed in a binder, and a coating is formed on the surface of the reinforcing bar, which is bonded with styrene resin and asphalt using the inorganic powder as an aggregate. Since this film is chemically stable, adverse effects such as a decrease in film strength and an increase in water absorption can be avoided over a long period of time. Further, since the binder is an aqueous emulsion, no harmful gas is generated.
[0010]
Furthermore, since there is much quantity of carbonates, such as limestone powder, the flexibility and rust prevention property of a rust prevention film improve, and it is economical. Further, natural limestone is generally used as the alkaline earth carbonate. Calcium carbonate powder as an industrial raw material can be used without any problem. There is no problem even if this limestone contains non-silicic impurities such as magnesium carbonate and barium carbonate. And, it was less than 5% by weight when the aqueous emulsion of styrenic resin was used as a binder of 5 to 25% by weight as a solid, and the aqueous emulsion of asphalt was used as a binder consisting of 5 to 15% by weight as a solid. In this case, the rust prevention performance is remarkably lowered, and if it exceeds 25% by weight, the adhesion with ALC is lowered and the rust prevention performance is deteriorated. Desirably, the former is 8 to 16% by weight and the latter is 7 to 12% by weight.
[0011]
In addition, as an aqueous emulsion of a styrene resin, an aqueous emulsion such as polystyrene, styrene butadiene, styrene acrylonitrile, polybutadiene styrene, acrylonitrile butadiene styrene or the like can be used. Or an aqueous emulsion of a styrene butadiene resin having a styrene bond amount of 55 to 75% by weight and partially modified and cured with an unsaturated carboxylic acid. This is because when the styrene bond amount is less than 55% by weight, the rust preventive film is soft and has poor adhesion, and when it is 76% by weight or more, the film is hard and has poor flexibility. Moreover, since unsaturated carboxylic acid can provide flexibility in addition to the curing action, it is preferable to use a small amount even when the amount of styrene bond is 65 to 75% by weight.
[0012]
Even when the amount of styrene bond is less than 55% by weight, a film having a desired hardness can be formed by copolymerizing an appropriate amount of a substance having a double bond such as an unsaturated carboxylic acid. In addition, slaked lime does not necessarily need to be added to the inorganic material, but when 5% by weight or less of slaked lime is added, the pH and viscosity of the rust inhibitor can be adjusted, and the adhesion of the rust inhibitor film and rust prevention Performance can be improved. However, when the added amount of slaked lime exceeds 5% by weight, the viscosity of the rust preventive agent increases remarkably, making it difficult to adjust the film thickness of the rust preventive coating, and the rust preventive agent is easily gelled. Therefore, it is desirably 2 to 4%. Furthermore, if an inhibitor is added to the inorganic substance, the rust prevention performance can be improved, and if a fiber such as carbon fiber is added, cracking of the rust prevention film can be prevented. In addition, you may add a dispersing agent, an antifoamer, iron oxide, titanium oxide, etc. as needed.
[0013]
【Example】
An embodiment of the present invention will be described below. This rust inhibitor is an aqueous emulsion of styrene butadiene resin (trade name Crossren SPX-1 manufactured by Takeda Pharmaceutical Co., Ltd.) having a solid content of about 70% by weight of styrene and about 30% by weight of butadiene as a main component. 3 to 30% by weight as solid content and 55% by weight aqueous asphalt emulsion (trade name Flynn Coat NO5 manufactured by Showa Shell Sekiyu KK) as solid content and 3 to 20% by weight as binder (a), limestone The powder (trade name CX made by Ryoko Lime) is 60 to 85% by weight (b), and as an additive, the additive (trade name Mighty 150R made by Kao) is 0.5% by weight, and an antifoaming agent. (Daiichi Kogyo Seiyaku brand name anti-floss) 0.1% by weight is added, and a proper amount of water and a pH adjuster (reagent grade 1 slaked lime) are added to these mixtures, and stirred for 30 minutes to form a slurry-like rust preventive. Make medicine It was.
[0014]
Moreover, the conventional rust preventive agent used in order to compare performance is the following one type. As the binder (a), an aqueous emulsion of the same styrene butadiene resin as described above is used in a solid content of 20% by weight, and an aqueous asphalt emulsion is used in a solid content of 7% by weight. Special powder) 70% by weight and 3% by weight of slaked lime, and other dispersants and antifoaming agents are the same as the previous examples.
[0015]
And the operation | work which hot-air-drys at 80 degreeC after immersing a reinforcing bar with a diameter of 5.5 mm in each said rust preventive agent was repeated, and the antirust film with an average thickness of 200 micrometers was formed. These reinforcing reinforcing bars were fixed to the mold, and ALC having a specific gravity of 0.5 was produced according to the usual method. Thirteen types of samples were prepared by cutting the ALC thus manufactured so that the reinforcing bar was positioned at the center in the vertical direction of the 4 × 4 × 16 cm prism.
[0016]
The test method and performance criteria for each sample obtained in this way are as follows, and the test results are shown in Table 1. Test number 1 in the table uses a conventional rust inhibitor, and test numbers 2 to 6 are examples using the rust inhibitor of the present invention. ) Is an aqueous emulsion of SBR having an styrene bond amount of about 55% by weight and an aqueous emulsion of styrene butadiene resin modified and cured with an unsaturated carboxylic acid. Moreover, although test numbers 7-12 are all comparative examples, test numbers 7-11 are examples in which the blending amount of the binder and limestone is outside the scope of the present invention, and test numbers 12 and 13 each have a styrene bond amount. This is an example in which an aqueous emulsion of about 55% by weight and 85% of high styrene SBR is used.
Adhesive force: Value obtained by dividing the maximum load by the punching method by the surface area of the reinforcing bar ○: 20 kg / cm 2 or more Δ: 15-20 kg / cm 2
×: Less than 15 kg / cm 2 Rust prevention: Conforms to JIS A5416, but for easier discrimination, the sample was immersed in 3% saline before starting the test and every 2 days, and the test period was 2 The rusting area was measured as a week.
A: Less than 0.5% B: 0.5-2.0%
×: 2.0% or more Flexibility ○: No cracks occur even when bent at 45 degrees.
X: A crack occurs when bent at 45 degrees.
Pot life: Viscosity of the rust preventive agent in the container, both when the rust preventive agent is put in a container with a lid and left in a sealed state, and when 10% of the rust preventive agent in the container is replaced with a new product every day. Observe changes, gelation, and sedimentation.
○: Does not change for more than one month, or returns to the original state if stirred even if partly settled.
X: Gelation within 1 month or stirring does not return to the original state.
[0017]
[Table 1]
As is apparent from Table 1, test number 1 using a conventional rust inhibitor is inferior in rust resistance. On the other hand, in the examples of the present invention with test numbers 2 to 6, all performances are satisfied. In particular, the blends of Test Nos. 2 to 3 showed the most excellent performance. In addition, when the slaked lime of test number 4 is not blended, the adhesion and rust resistance are slightly reduced compared to other examples, and when the binder of test number 6 is changed, the rust resistance is slightly low, There is no problem in practical use.
[0019]
Test numbers 7, 8 and 9, 10 of the comparative examples are too high or too low in the blending ratio of A or B, so that either or both of adhesion and rust prevention properties do not reach the standard value, and test number 11 Since the compounding ratio of D is too high, workability deteriorates and there is a problem in pot life and adhesion. Furthermore, even in Example Test Nos. 12 and 13 in which an aqueous emulsion of SBR having a styrene bond amount of about 55% by weight and 85% by weight is used, there is a problem in adhesion and flexibility.
[0020]
【The invention's effect】
As described in detail above, the rust preventive agent of the present invention is excellent in workability and storability, and can form a rust preventive film on reinforcing bars of any shape and size. Since the adhesive force is large and flexible, cracks do not occur and excellent rust prevention properties can be obtained. Therefore, the rebar does not corrode even in areas where salt damage is likely to occur, such as coastal areas. Moreover, this rust preventive agent is comparatively inexpensive and excellent in economic efficiency, and can be used not only for reinforcing reinforcing bars of ALC but also for rust prevention of reinforcing bars of general reinforced concrete.
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33784896A JP3981993B2 (en) | 1996-12-18 | 1996-12-18 | Rust prevention agent for lightweight cellular concrete reinforced steel bars |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33784896A JP3981993B2 (en) | 1996-12-18 | 1996-12-18 | Rust prevention agent for lightweight cellular concrete reinforced steel bars |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10176292A JPH10176292A (en) | 1998-06-30 |
| JP3981993B2 true JP3981993B2 (en) | 2007-09-26 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33784896A Expired - Fee Related JP3981993B2 (en) | 1996-12-18 | 1996-12-18 | Rust prevention agent for lightweight cellular concrete reinforced steel bars |
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| Country | Link |
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| JP (1) | JP3981993B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4890127B2 (en) * | 2006-07-14 | 2012-03-07 | 住友金属鉱山シポレックス株式会社 | Emulsion composition for ALC rebar anti-rust treatment material |
| JP2009102700A (en) * | 2007-10-24 | 2009-05-14 | Sumitomo Kinzoku Kozan Siporex Kk | Rust preventive for autoclaved lightweight concrete reinforcing bar |
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1996
- 1996-12-18 JP JP33784896A patent/JP3981993B2/en not_active Expired - Fee Related
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| Publication number | Publication date |
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| JPH10176292A (en) | 1998-06-30 |
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