JPH0341533Y2 - - Google Patents
Info
- Publication number
- JPH0341533Y2 JPH0341533Y2 JP10317684U JP10317684U JPH0341533Y2 JP H0341533 Y2 JPH0341533 Y2 JP H0341533Y2 JP 10317684 U JP10317684 U JP 10317684U JP 10317684 U JP10317684 U JP 10317684U JP H0341533 Y2 JPH0341533 Y2 JP H0341533Y2
- Authority
- JP
- Japan
- Prior art keywords
- corrosion
- steel material
- tape
- zinc
- concrete
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 229910000831 Steel Inorganic materials 0.000 claims description 67
- 239000010959 steel Substances 0.000 claims description 67
- 239000000463 material Substances 0.000 claims description 58
- 238000005260 corrosion Methods 0.000 claims description 51
- 239000011513 prestressed concrete Substances 0.000 claims description 51
- 230000007797 corrosion Effects 0.000 claims description 46
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 23
- 229910052725 zinc Inorganic materials 0.000 claims description 18
- 239000011701 zinc Substances 0.000 claims description 18
- 239000011888 foil Substances 0.000 claims description 8
- 229910045601 alloy Inorganic materials 0.000 claims description 6
- 239000000956 alloy Substances 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 6
- 239000012790 adhesive layer Substances 0.000 claims description 5
- 239000002390 adhesive tape Substances 0.000 claims description 2
- 239000004567 concrete Substances 0.000 description 21
- 229910052751 metal Inorganic materials 0.000 description 21
- 239000002184 metal Substances 0.000 description 21
- 238000000034 method Methods 0.000 description 18
- 239000000853 adhesive Substances 0.000 description 11
- 230000001070 adhesive effect Effects 0.000 description 11
- 230000000694 effects Effects 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 8
- 239000011440 grout Substances 0.000 description 5
- 239000003112 inhibitor Substances 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 5
- 238000004210 cathodic protection Methods 0.000 description 4
- 238000005536 corrosion prevention Methods 0.000 description 4
- 238000005336 cracking Methods 0.000 description 4
- 238000005246 galvanizing Methods 0.000 description 4
- 238000011282 treatment Methods 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 238000009825 accumulation Methods 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 238000004804 winding Methods 0.000 description 3
- 241001163841 Albugo ipomoeae-panduratae Species 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- UGZADUVQMDAIAO-UHFFFAOYSA-L zinc hydroxide Chemical compound [OH-].[OH-].[Zn+2] UGZADUVQMDAIAO-UHFFFAOYSA-L 0.000 description 2
- 229940007718 zinc hydroxide Drugs 0.000 description 2
- 229910021511 zinc hydroxide Inorganic materials 0.000 description 2
- 229910000967 As alloy Inorganic materials 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000011083 cement mortar Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
Landscapes
- Bridges Or Land Bridges (AREA)
- Reinforcement Elements For Buildings (AREA)
- Laminated Bodies (AREA)
Description
【考案の詳細な説明】
本考案はプレストレストコンクリート（PC）
鋼材に関し、詳しくは陰極防食作用を有する亜
鉛、アルミニウムまたはこれらの合金の箔または
薄板からなるテープをPC鋼材に巻回させること
によつて、耐食性を向上させた耐食性PC鋼材に
関する。[Detailed explanation of the invention] This invention is made of prestressed concrete (PC).
The present invention relates to steel materials, and specifically relates to a corrosion-resistant PC steel material whose corrosion resistance is improved by winding a tape made of foil or thin plate of zinc, aluminum, or an alloy thereof, which has a cathodic protection effect, around the PC steel material.
鉄道橋などに用いられるPC構造橋においては
コンクリートの補強にプレストレスが利用され、
プレストレスを与えるためにはPC鋼材が用いら
れている。PC鋼材としては鋼線、撚線、鋼棒等
が使用されており、PC鋼材を用いてプレストレ
スを与える方法にはプレテンシヨニング方式とポ
ストテンシヨニング方式とがある。 Prestress is used to reinforce concrete in PC structure bridges used for railway bridges, etc.
PC steel is used to apply prestress. Steel wires, stranded wires, steel bars, etc. are used as the prestressing steel material, and there are two methods of applying prestress using the prestressing steel material: a pretensioning method and a posttensioning method.
従来、腐食の問題に関しては、ポストテンシヨ
ニング方式でグラウトしない場合、あるいはプレ
テンシヨニング方式による場合でもかぶり厚さが
小さい場合にPC鋼材が腐食する場合があるので、
PC鋼材に防食処理がなされている。そして、防
食処理には高分子材料の塗布や溶融亜鉛メツキな
どのメタルコーテイングが用いられ、またポスト
テンシヨニング方式でグラウトしない場合は、プ
ラスチツク系耐食材料を塗布した後に防水紙を巻
き付ける方法などが採られている。しかし、これ
らの防食法は従来比較的軽視される傾向があつ
た。 Conventionally, regarding the problem of corrosion, PC steel materials may corrode if the post-tensioning method is not grouted, or even if the pre-tensioning method is used and the cover thickness is small.
Anti-corrosion treatment has been applied to the PC steel material. Anti-corrosion treatments include applying polymeric materials and metal coatings such as hot-dip galvanizing.If post-tensioning is not used to grout, methods such as applying a plastic anti-corrosion material and wrapping it with waterproof paper are used. It is taken. However, these anti-corrosion methods have traditionally tended to be neglected.
一方、近年海岸付近に設置されたコンクリート
橋における塩害が問題視され、内部の鋼材が腐食
して損傷を受けたことによるコンクリートの剥離
が多数報告され、著しい場合にはPC鋼材が破断
した事例も報告されている。このことからPC鋼
材の強度を確保することがPC橋には必須である
ので、その防食方法が真剣に検討されており、ま
たこれらの損傷の原因は波浪を浴びるコンクリー
ト橋の表面が乾燥と湿潤のくり返しを受けること
によつて、その内部に30Kg／m3もの塩化物が蓄積
していることに起因することが明らかとなるに到
つた。 On the other hand, in recent years, salt damage to concrete bridges built near the coast has become a problem, and there have been many reports of concrete peeling due to corrosion and damage to the internal steel, and in severe cases, there have been cases where the prestressing steel has fractured. It has been reported. For this reason, securing the strength of the prestressing steel is essential for prestressed bridges, so corrosion prevention methods are being seriously considered.Additionally, the cause of these damages is due to dryness and dampness of the surface of concrete bridges exposed to waves. By repeating this process, it became clear that this was due to the accumulation of 30 kg/m 3 of chloride inside.
このようなコンクリート中での塩化物の蓄積と
濃縮が明らかとなつた現在、従来のかぶり厚さに
よる効果を信じての無防食は勿論のこと、従来よ
り採用されている防食法である高分子材料の塗布
や溶解亜鉛メツキあるいはプラスチツク系耐食材
料塗布と防水紙の併用法は、それぞれ次のように
問題がある。すなわち高分子材料塗布は皮膜が長
年月の経過によつてクラツク等を生じその部位か
ら腐食が進行する。一方、溶融亜鉛メツキはまず
そのメツキ操作のための加熱がPC鋼材の強度低
下を招き望ましくないのと同時に、亜鉛層とPC
鋼材とが金属結合状況にあるためクツシヨンがな
く亜鉛の腐食生成物が生じた場合の体積膨脹がも
ろにコンクリートに伝わり、コンクリートの割れ
を招く欠点がある。また、プラスチツク系耐食材
料塗布と防水紙との併用は基本的な耐食性の不足
と劣化ひび割れとにより長時間後に一部で錆が発
生すると著しい腐食を招く欠点がある。 Now that the accumulation and concentration of chlorides in concrete has become clear, we can go beyond non-corrosion prevention based on the effectiveness of conventional cover thickness, to using polymers, which is the conventional corrosion prevention method. The combination of applying materials, dissolving galvanizing, or applying plastic corrosion-resistant materials and waterproof paper has the following problems. In other words, when coating a polymeric material, the film develops cracks and the like over time, and corrosion progresses from those areas. On the other hand, hot-dip galvanizing is undesirable because the heating required for the plating process lowers the strength of the prestressed steel, and at the same time,
Because there is a metallic bond with the steel material, there is no cushion, and the volumetric expansion when corrosion products of zinc occur is transmitted directly to the concrete, resulting in cracking of the concrete. Furthermore, the combined use of plastic corrosion-resistant material and waterproof paper has the drawback of insufficient basic corrosion resistance and deterioration cracking, which leads to severe corrosion if rust occurs in some areas after a long period of time.
本考案はかかる問題点を解決すべくなされたも
のであつて、PC鋼材の防食を図ると共に、生成
する防食生成物がコンクリートの割れを招かない
耐食性PC鋼材を提供することを目的とし、特に
PC鋼材とコンクリートとの間の付着強度があま
り重要でないポストテンシヨニング方式の場合に
好適に利用される。 The present invention was made to solve these problems, and aims to provide a corrosion-resistant PC steel material that prevents corrosion of the prestressing steel material and does not cause corrosion-resistant products to cause cracking of concrete.
It is suitably used in the case of a post-tensioning method where the adhesive strength between the prestressing steel and concrete is not so important.
本考案者らは上記目的に沿つて検討の結果、陰
極防食作用を有する亜鉛、アルミニウムまたはこ
れらの合金の箔または薄板からなるテープをPC
鋼材に巻回させることによつて、PC鋼材を被覆
して防食するのみならず、必要に応じ陰極防食作
用をもたらし、その腐食生成物は陰極インヒビタ
ーとして働き、水素発生もなく上記目的が達成さ
れることを見い出し本考案に到達した。 As a result of studies in line with the above objectives, the present inventors developed a tape made of foil or thin plate of zinc, aluminum, or an alloy thereof that has a cathodic protection effect.
By winding it around the steel material, it not only coats the prestressing steel material and prevents corrosion, but also provides cathodic protection when necessary, and the corrosion products act as cathodic inhibitors, achieving the above purpose without hydrogen generation. We discovered this and came up with this idea.
すなわち本考案は、PC鋼材に亜鉛またはアル
ミニウムあるいはそれらの合金の箔または薄板か
らなるテープを巻回させたことを特徴とする耐食
性PC鋼材にある。 That is, the present invention resides in a corrosion-resistant PC steel material, which is characterized in that a tape made of foil or thin plate of zinc, aluminum, or an alloy thereof is wound around the PC steel material.
本考案において、PC鋼材を巻回するテープは
鋼材に対し陰極防食作用をなす金属である亜鉛ま
たはアルミニウムまたはそれらの合金である必要
があり、特に薄板または箔に容易に加工し得るこ
と、腐食生成物が陰極インヒビター効果を持ちア
ルカリ側で電位の大巾な卑化がないこと等を考え
あわせると亜鉛の薄板または箔から得られるテー
プが望ましい。テープの厚みは施工のし易さから
考えると、１mm以下であることが望ましく、最小
の厚みは防食性能から見て0.03mm以上あることが
望ましい。テープの巾は施工しやすければよいの
で実質的に制限はない。 In the present invention, the tape for wrapping the PC steel material must be made of zinc or aluminum, or an alloy thereof, which is a metal that has a cathodic protection effect on the steel material, and must be particularly easy to process into thin plates or foils, and must be able to produce corrosion. Considering the fact that the material has a cathodic inhibitor effect and that there is no significant debasement of the potential on the alkaline side, a tape made of zinc thin plate or foil is desirable. The thickness of the tape is preferably 1 mm or less in terms of ease of application, and the minimum thickness is preferably 0.03 mm or more in terms of anticorrosion performance. There is no practical limit to the width of the tape as long as it is easy to apply.
亜鉛、アルミニウムまたはこれらの合金の箔ま
たは薄板からなるテープ（以下、金属テープと総
称する）に粘着テープ等の粘着剤が塗布されてい
ると、PC鋼材に金属テープを貼り付ける際に施
工しやすく、またグラウトを注入する際に巻回し
た金属テープが剥離することがないので好都合で
ある。ただし、金属テープには防食法としての信
頼性を高めるため犠性陽極としての作用も期待す
るので、粘着剤を用いた場合、金属テープとPC
鋼材との間に電気的接触を保つ必要がある。この
ためには粘着剤が導電性粘着剤であるか、非導電
性粘着剤であつても粘着剤の塗り残し部を意図的
に作る等の処理をして、粘着面を金属接触する部
分を作つておけばよい。なお、粘着剤を用いない
場合は金属テープに直接PC鋼材に巻回すれば電
気的接触は十分保たれる。 Tapes made of foil or thin plates of zinc, aluminum, or their alloys (hereinafter collectively referred to as metal tapes) coated with an adhesive such as adhesive tape make it easier to apply metal tapes to prestressing steel materials. This is also advantageous since the wrapped metal tape will not peel off when grout is injected. However, metal tape is expected to act as a sacrificial anode to increase its reliability as a corrosion prevention method, so if adhesive is used, metal tape and PC
Electrical contact must be maintained with the steel. To do this, whether the adhesive is a conductive adhesive or a non-conductive adhesive, it is necessary to intentionally leave unpainted areas of the adhesive so that the adhesive surface does not come in contact with metal. Just make it. If no adhesive is used, electrical contact can be maintained sufficiently by wrapping the metal tape directly around the PC steel material.
PC鋼材への金属テープの巻回方法は螺旋状に
オーバーラツプさせながら巻回する方法など種々
の方法が考えられるがどの方法でも良く、全表面
を巻回して被覆させるか、腐食し易い特定の部分
だけを巻回するか、もしくは間隔をあけながら巻
回するかは、コンクリート橋が設置される環境に
適宜合わせ選定すればよい。 There are various ways to wrap the metal tape around the prestressing steel material, such as overlapping the tape in a spiral pattern, but any method is fine, either covering the entire surface or covering specific areas that are prone to corrosion. Whether to wrap only one part or to wrap at intervals can be selected depending on the environment in which the concrete bridge will be installed.
以上のように亜鉛等の金属テープをPC鋼材に
巻回させた防食性PC鋼材は、金属テープによる
被覆防食効果および犠性陽極作用効果、腐食生成
部による陰極インヒビター効果により防食性が優
れ、またPC鋼材の機械的性質は何等悪影響を受
けないのでPC鋼材の機械的性質と半永久的に確
保させるものである。 As mentioned above, the corrosion-resistant PC steel material made by wrapping a metal tape such as zinc around the PC steel material has excellent corrosion resistance due to the coating anticorrosion effect and sacrificial anode effect of the metal tape, and the cathode inhibitor effect of the corrosion generating part. The mechanical properties of the prestressed steel material are not adversely affected in any way, so the mechanical properties of the prestressed steel material are guaranteed semi-permanently.
また、海岸際のコンクリート橋を想定した場合
前述したようにコンクリート中には30Kg／m3もの
塩分が濃縮する。そして、この場合コンクリート
の比抵抗は1000Ω−cm以下にまで低下し、コンク
リートは電解質となつているとみなせる。そのよ
うな環境下にあるポストテンシヨニング方式によ
るPC橋では、コンクリートの中性化に伴なつて
シースは腐食して穴があき、さらにグラウトに腐
食媒が浸入してPC鋼材を腐食するに到つている。
そこで本考案の耐食性PC鋼材を従来のPC鋼材に
変えて使用すると、コンクリートの中性化と高濃
度の塩分とによつてシースが腐食して穴があき、
グラウト内に腐食媒が浸透するまでは同様である
が、PC鋼材に被覆してある亜鉛等の金属箔がま
ずPC鋼材を被覆防食する。しかし亜鉛を例にと
れば中性化が進んでいない間に腐食媒に接すると
孔食を生ずることもある。しかしこのような孔食
を生じた場合、または何等かの原因で金属テープ
層が腐食し、あるいは剥離した場合でも正常部の
金属テープの犠性陽極作用によつてPC鋼材の腐
食は避けられる。さらに亜鉛を例にとれば亜鉛の
腐食生成物（主に水酸化亜鉛）は陰極側となる
PC鋼材の上に沈着し、これが陰極インヒビター
効果を持つため万一金属テープの金属分が全て犠
性陽極作用によつて消耗してしまうというような
事態でもPC鋼材の腐食は極力に押さえられる。
また亜鉛の腐食生成物はその近辺のPHを７近くに
もつてゆく効果があるのでこの効果によつて亜鉛
の自己腐食は押さえられ、亜鉛の陰極インヒビタ
ー効果はより有効となり、さらに電位が貴化する
ので水素の発生は生ぜず、水素脆性の心配もな
い。 Furthermore, in the case of a concrete bridge near the coast, as mentioned above, as much as 30 kg/ m3 of salt will be concentrated in the concrete. In this case, the specific resistance of the concrete decreases to below 1000 Ω-cm, and the concrete can be considered to be an electrolyte. In post-tensioned PC bridges in such environments, the sheath corrodes and becomes punctured as the concrete neutralizes, and corrosive media enters the grout, corroding the prestressing steel. It has arrived.
Therefore, when the corrosion-resistant PC steel of this invention is used in place of conventional PC steel, the sheath will corrode due to the neutralization of the concrete and the high concentration of salt, resulting in holes.
The process is the same until the corrosive medium penetrates into the grout, but the metal foil such as zinc that coats the prestressing steel material first coats the prestressing steel material to prevent corrosion. However, taking zinc as an example, if it comes into contact with a corrosive medium before neutralization has progressed, pitting corrosion may occur. However, even if such pitting corrosion occurs, or even if the metal tape layer corrodes or peels off for some reason, corrosion of the PC steel material can be avoided by the sacrificial anodic action of the metal tape in the normal area. Furthermore, if we take zinc as an example, the corrosion products of zinc (mainly zinc hydroxide) will be on the cathode side.
It is deposited on the PC steel material and has a cathodic inhibitor effect, so even in the unlikely event that all the metal in the metal tape is consumed by the sacrificial anodic action, corrosion of the PC steel material will be suppressed to the utmost.
In addition, the corrosion products of zinc have the effect of bringing the pH of the surrounding area close to 7, so this effect suppresses the self-corrosion of zinc, making the cathodic inhibitor effect of zinc more effective, and further increasing the potential. Therefore, no hydrogen is generated and there is no concern about hydrogen embrittlement.
さらに、本考案において、例えば亜鉛箔テープ
を考えた場合、溶融亜鉛メツキ処理したものと比
べると、まずPC鋼材の性能劣化が溶融メツキし
た場合のように起こることがないことも一つの特
徴である。すなわち本考案の耐食性PC鋼材はPC
鋼の性能を出したあとの熱履歴がないため、また
合金層等の脆化層が生成しないため、強度特性お
よび疲労特性の劣化がない。また本考案に用いる
金属テープは粘着剤を用い、または用いないで
PC鋼材に巻回したものであるから金属テープの
腐食生成物が発生してもそれによる体積膨張は粘
着剤層またはたるみ空間に吸収されるので溶融メ
ツキした場合のように膨張の吸収ができずコンク
リートの割れを招くというような心配がない。な
お、本考案の耐食性PC鋼材となすに当つてはPC
鋼材に付着した油や水分を拭いて金属テープを巻
回すればよく、非常に簡便に巻回作業が行なえ
る。 Furthermore, in this invention, when considering a zinc foil tape, for example, one of the characteristics is that compared to a hot-dip galvanized one, the performance deterioration of the prestressing steel material does not occur as in the case of hot-dip galvanizing. . In other words, the corrosion-resistant PC steel material of this invention is PC
Because there is no thermal history after the performance of steel is achieved, and because no brittle layers such as alloy layers are formed, there is no deterioration in strength and fatigue properties. In addition, the metal tape used in this invention may or may not use an adhesive.
Since it is wrapped around PC steel material, even if corrosion products occur on the metal tape, the resulting volume expansion is absorbed by the adhesive layer or slack space, so the expansion cannot be absorbed as in the case of melt plating. There is no need to worry about the concrete cracking. In addition, when making the corrosion-resistant PC steel material of this invention, PC
All you have to do is wipe off any oil or moisture that has adhered to the steel material and then wind the metal tape, making the winding work very simple.
以上の説明はポストテンシヨニング方式のPC
橋について述べてきたが、本考案の耐食性PC鋼
材の鋼材と金属テープとの間の付着力がコンクリ
ートにプレストレスを与える荷重を伝えるには不
足であるからである。しかし、プレテンシヨニン
グ方式のPC橋でもボンドレス工法をとる場合は
付着力がいらないので、本考案の耐食性PC鋼材
がその部分に利用でき、プレテンシヨニング桁に
曲線状のポストテンシヨニング用ケーブルを挿入
し、プレテンシヨニングとポストテンシヨニング
を併用する場合にもむろん利用できる。またポス
トテンシヨニング方式においてグラウトを注入し
ない場合も勿論有効である。 The above explanation uses a post-tensioning PC.
This is because the adhesion between the corrosion-resistant prestressing steel material of the present invention and the metal tape is insufficient to transmit the load that applies prestress to the concrete, as described above regarding bridges. However, if bondless construction is used for pre-tensioned PC bridges, adhesion is not required, so the corrosion-resistant PC steel material of this invention can be used for that part, and curved post-tensioning cables are installed on the pre-tensioned girder. Of course, it can also be used when inserting it and using pretensioning and posttensioning together. Of course, it is also effective to use the post-tensioning method without injecting grout.
以下、実施例および比較例に基づき本考案を詳
述する。 The present invention will be described in detail below based on Examples and Comparative Examples.
実施例および比較例
ポルトランドセメント310Kg／m3、細骨材850
Kg／m3、粗骨材970Kg／m3、水150Kg／m3、食塩30
Kg／m3、減水剤1.9Kg／m3、AE剤0.19Kg／m3の配
合でコンクリートを調合し、かぶり厚５cmの条件
下で26φのシースを埋込んだ。初期塩分（食塩
量）を30Kg／m3としたのは実際の蓄積例に合わせ
促進試験を能率良く行なうためである。埋込んだ
シース管の長さは25cmであるが、中央部およびそ
れから５cmづつ左右に離れた部分に直径２mmの細
孔を貫通させ、実際の場合の腐食孔に対応させ
た。コンクリートが固化したのち、JIS Ｇ 3536
SWPR 7Aに規定される７本撚り12.4mmφPC鋼撚
線を用い、これに何らの処理を施さないものを比
較例とした。また、この７本撚り12.4mmφPC鋼
撚線に、第１図に示すように0.1mm厚、50mmの亜
鉛箔テープを巻回したものを実施例として用い
た。なお、第１図は本考案の耐食性PC鋼材の一
実施例を示す図であり、１はPC鋼材、２は粘着
剤層、３は亜鉛箔テープおよび４はテープのオー
バーラツプ部をそれぞれ示す。Examples and comparative examples Portland cement 310Kg/m 3 , fine aggregate 850
Kg/m 3 , coarse aggregate 970Kg/m 3 , water 150Kg/m 3 , salt 30
Kg/m 3 , water-reducing agent 1.9 Kg/m 3 , and AE agent 0.19 Kg/m 3 were mixed into concrete, and a 26φ sheath was embedded under the condition of a cover thickness of 5 cm. The initial salinity (amount of salt) was set at 30Kg/m 3 in order to efficiently perform the acceleration test in accordance with actual accumulation examples. The length of the embedded sheath tube was 25 cm, and pores with a diameter of 2 mm were penetrated in the center and in parts separated by 5 cm from the center to the left and right to correspond to the corrosion holes in the actual case. After concrete hardens, JIS G 3536
As a comparative example, a 7-strand 12.4 mmφ PC steel stranded wire specified in SWPR 7A was used, and no treatment was applied to it. Further, as shown in FIG. 1, a 0.1 mm thick, 50 mm zinc foil tape was wound around the 7-strand 12.4 mmφ PC steel stranded wire, and this was used as an example. In addition, FIG. 1 is a diagram showing an example of the corrosion-resistant PC steel material of the present invention, in which 1 represents the PC steel material, 2 represents the adhesive layer, 3 represents the zinc foil tape, and 4 represents the overlapping portion of the tape.
実施例および比較例のPC鋼撚線をそれぞれ25
cmの長さとして別個の上記コンクリートに埋込ん
だシースの中にシースに触れないように40％の塩
分を含まない水分で練つたセメントモルタルを注
入して固定した。 25 PC steel stranded wires of Example and Comparative Example each
Cement mortar mixed with 40% salt-free water was injected into the sheath, which was embedded in the above-mentioned concrete as a length of cm, and fixed so as not to touch the sheath.
実施例に用いた亜鉛箔テープにはストライプ状
に粘着剤がついていない部分を作つてあつたので
耐食性PC鋼材を形成させたのちPC鋼材と亜鉛間
の導通を調べたが実質的に抵抗はなかつた。 The zinc foil tape used in the example had a striped area with no adhesive attached, so after forming a corrosion-resistant PC steel material, conduction between the PC steel material and zinc was examined, but there was virtually no resistance. Ta.
蒸気養生後、上記の手順で形成させた実施例お
よび比較例の供試体２個の端面シール処理をした
後、これらを海水中に浸漬し、さらに50℃に保つ
たウオーターバス中に入れ10ケ月間保持した。10
ケ月後試料を取り出して破壊して観察したが、比
較例も実施例でもシースは著しい腐食をおこして
いた。また、比較例のPC撚線も重大な腐食を起
していた。一方、実施例の場合は亜鉛に白錆が発
錆し、一部で錆がPC鋼材側に貫通しておりPC鋼
材の表面には一面に水酸化亜鉛と考えられる白錆
が付着していたが、PC鋼材の腐食（赤錆）は認
められなかつた。 After steam curing, the two specimens of the example and comparative example formed according to the above procedure were subjected to end face sealing treatment, then immersed in seawater and then placed in a water bath maintained at 50°C for 10 months. held for a while. Ten
After several months, the samples were taken out, destroyed, and observed, and it was found that the sheaths of both the comparative example and the example had undergone significant corrosion. Furthermore, the PC stranded wire of the comparative example also suffered from severe corrosion. On the other hand, in the case of the example, white rust developed on the zinc, and in some areas, the rust penetrated to the PC steel material side, and the surface of the PC steel material was covered with white rust, which was thought to be zinc hydroxide. However, no corrosion (red rust) of the PC steel material was observed.
この実施例と比較例の比較から明らかなよう
に、本考案の耐食性PC鋼材は耐食性において著
しい向上を示すものである。 As is clear from the comparison between this example and the comparative example, the corrosion-resistant PC steel material of the present invention shows a significant improvement in corrosion resistance.
第１図は本考案の耐食性PC鋼材の一実施例を
示す図であ。
１：PC鋼材、２：粘着剤層、３：亜鉛箔テー
プ、４：テープのオーバーラツプ部。
FIG. 1 is a diagram showing an embodiment of the corrosion-resistant PC steel material of the present invention. 1: PC steel material, 2: adhesive layer, 3: zinc foil tape, 4: tape overlap part.
Claims (1)
はアルミニウムあるいはそれらの合金の箔また
は薄板からなるテープを巻回させたことを特徴
とする耐食性プレストレストコンクリート鋼
材。 ２ 前記テープとプレストレストコンクリート鋼
材間に粘着剤層が設けられている前記実用新案
登録請求の範囲第１項記載のプレストレストコ
ンクリート鋼材。 ３ 前記粘着剤層が粘着テープである前記実用新
案登録請求の範囲第２項記載の耐食性プレスト
レストコンクリート鋼材。 ４ ポストテンシヨニング方式のプレストレスト
コンクリート橋に用いられる前記実用新案登録
請求の範囲第１項、第２項または第３項記載の
耐食性プレストレストコンクリート鋼材。[Claims for Utility Model Registration] 1. A corrosion-resistant prestressed concrete steel material, characterized in that a tape made of foil or thin plate of zinc, aluminum, or an alloy thereof is wound around a prestressed concrete steel material. 2. The prestressed concrete steel material according to claim 1, wherein an adhesive layer is provided between the tape and the prestressed concrete steel material. 3. The corrosion-resistant prestressed concrete steel material according to claim 2, wherein the adhesive layer is an adhesive tape. 4. The corrosion-resistant prestressed concrete steel material according to claim 1, 2, or 3 of the utility model registration claim, which is used in a post-tensioning prestressed concrete bridge.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10317684U JPS6119010U (en) | 1984-07-10 | 1984-07-10 | Corrosion resistant prestressed concrete steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10317684U JPS6119010U (en) | 1984-07-10 | 1984-07-10 | Corrosion resistant prestressed concrete steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6119010U JPS6119010U (en) | 1986-02-04 |
| JPH0341533Y2 true JPH0341533Y2 (en) | 1991-08-30 |
Family
ID=30662570
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10317684U Granted JPS6119010U (en) | 1984-07-10 | 1984-07-10 | Corrosion resistant prestressed concrete steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6119010U (en) |
-
1984
- 1984-07-10 JP JP10317684U patent/JPS6119010U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6119010U (en) | 1986-02-04 |
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