JP2809805B2 - Corrosion protection method for RC structures - Google Patents
Corrosion protection method for RC structuresInfo
- Publication number
- JP2809805B2 JP2809805B2 JP2088134A JP8813490A JP2809805B2 JP 2809805 B2 JP2809805 B2 JP 2809805B2 JP 2088134 A JP2088134 A JP 2088134A JP 8813490 A JP8813490 A JP 8813490A JP 2809805 B2 JP2809805 B2 JP 2809805B2
- Authority
- JP
- Japan
- Prior art keywords
- concrete
- corrosion
- structures
- corrosion protection
- protection method
- 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 - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Building Environments (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、RC（鉄筋コンクリート）構造物の鉄筋防食
方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for protecting a steel bar from reinforced concrete (RC).
RC構造物の鉄筋防食方法としては、コンクリート表面
の保護塗装、樹脂塗装鉄筋の使用、かぶりの確保等の方
策がとられている。Measures such as protective painting of concrete surfaces, use of resin-painted reinforcing bars, and securing of fogging have been taken as methods of corrosion protection for RC structures.
しかし、何れの方法によっても、恒久的な対策とはい
えず、コスト的にも高い方法である。個々の方法につい
ても他の問題点をあげると、 （１）コンクリート表面の保護塗装は施工性が悪い。However, any of these methods is not a permanent measure and is a costly method. Other problems with each method are as follows: (1) Protective coating on concrete surface is poor in workability.
（２）樹脂塗装鉄筋の使用は、弱点として取扱い時等に
傷が生ずるおそれがあり、傷部の補修を要する。またプ
レストレストコンクリート構造物の緊張材に適用するこ
とはできない。(2) The use of resin-coated steel rebar has a weak point that it may be damaged during handling, etc., and repair of the damaged part is required. Also, it cannot be applied to tendons of prestressed concrete structures.
（３）鉄筋かぶりを大きく確保することは構造断面が不
利になる。(3) Ensuring a large reinforcing bar cover disadvantageously results in a structural cross section.
等の問題があり、未だ根本的な解決策はなかった。There was no fundamental solution yet.
本発明者らは上記実情にかんがみ、RC構造物中の鉄筋
の腐食について多年に亘る研究を行った結果、簡易で効
果の大きい方法を見出し、この知見に基づいて本発明を
完成した。In view of the above-described circumstances, the present inventors have conducted research for many years on corrosion of reinforcing bars in RC structures, and as a result, have found a simple and effective method, and completed the present invention based on this finding.
本発明はこのような画期的な新技術を提供することを
目的とするものである。An object of the present invention is to provide such a revolutionary new technology.
上記問題点を解決する本発明の特徴的な技術手段は、
コンクリートの打設時に普通コンクリート中に、鉄分を
含みコンクリート中で化学的に安定な化学的安定物を混
入し、塩化物イオンのコンクリート中への浸入に対する
鉄筋の腐食反応を抑制することを特徴とするRC構造物の
鉄筋防食方法である。The characteristic technical means of the present invention for solving the above problems is as follows:
It is characterized by mixing iron-containing and chemically stable chemicals in the concrete at the time of placing concrete, thereby suppressing the corrosion reaction of the reinforcing steel bar when chloride ions enter the concrete. This is a method for preventing corrosion of RC structures.
本発明において化学的安定物とは、成分中に鉄粉、鉄
鉱石等のような鉄を含み、コンクリート中において化学
的に安定な材料を云う。このような材料は塩化物イオン
等の有害成分がコンクリート中に混入したとき、鋼の不
動態皮膜が破壊されるのを抑制する作用を有するもので
ある。In the present invention, a chemically stable material refers to a material which contains iron such as iron powder and iron ore in its components and is chemically stable in concrete. Such a material has an effect of suppressing the destruction of the passive film of steel when harmful components such as chloride ions are mixed into concrete.
コンクリート中の鉄筋は次のような環境条件の下にあ
る。Reinforcing bars in concrete are under the following environmental conditions.
（ａ） 炭酸作用によりコンクリート中のアルカリ度が
低下する。(A) The alkalinity in concrete decreases due to the carbonic action.
（ｂ） 塩化物イオン等の有害成分の混入により鋼の不
動態皮膜が破壊され、鋼が活性態となるなどの原因によ
り以下の反応が進行する。(B) The passivation film of steel is destroyed by the incorporation of harmful components such as chloride ions, and the following reaction proceeds due to factors such as activation of the steel.
Fe→Fe2+＋2e-（アノード反応） 上記反応により生じたOH-はFeと反応し、Fe（OH）２
やFe（OH）３となり、また、FeOOH、Fe2O3などを生じて
腐食が進行する。Fe → Fe 2+ + 2e - (anode reaction) OH produced by the reaction - reacts with Fe, Fe (OH) 2
And Fe (OH) 3 , and further, corrosion proceeds due to generation of FeOOH, Fe 2 O 3 and the like.
コンクリート中に鉄粉、鉄鉱石等のような、成分中に
鉄を含んだ化学的に安定した材料を混入することによ
り、上記の反応が抑制される作用がある。その理由とし
ては以下のように考えられる。By mixing a chemically stable material containing iron in a component, such as iron powder and iron ore, into concrete, the above-described reaction is suppressed. The reason is considered as follows.
（イ） コンクリート中に、鉄分を含んだ材料が分散さ
れることにより、磁場が発生する。鉄筋が磁場の中にお
かれることにより、外部との電気化学的反応が抑制され
る。(A) A magnetic field is generated by dispersing a material containing iron in concrete. By placing the rebar in a magnetic field, an electrochemical reaction with the outside is suppressed.
（ロ） コンクリート中に酸化鉄を混入することによ
り、鉄の酸化反応を飽和状態に近づけ、上記腐食の反応
速度を遅らせる。また、コンクリート中に混入した鉄粉
等は、化学的に安定しており、上記の作用は長期的に持
続する。(B) By mixing iron oxide into concrete, the oxidation reaction of iron approaches a saturated state, and the reaction rate of the above-mentioned corrosion is reduced. In addition, iron powder and the like mixed in concrete are chemically stable, and the above-mentioned action is maintained for a long time.
実施例１ 第１表に示す配合の普通コンクリート及び本発明に係
る鉄粉混入コンクリートの供試体を作成した。Example 1 Specimens of ordinary concrete having the composition shown in Table 1 and concrete mixed with iron powder according to the present invention were prepared.
供試体は、10×10×120cmのコンクリート梁に直径10m
m、長さ110cmの異形鉄筋（高炉品）を２本用いた。鉄筋
は、SB:KIP−B6とし、鉄筋のかぶりは2cmとした。The specimen is a 10 x 10 x 120 cm concrete beam with a diameter of 10 m.
Two deformed reinforcing bars (blast furnace products) having a length of 110 cm and a length of 110 cm were used. The reinforcing bar was SB: KIP-B6, and the covering of the reinforcing bar was 2 cm.
供試体は２本作製し、コンクリート打設後４週間散水
養生した後、３等分点状態で締付けてひび割れを導入し
た状態で海洋暴露した。Two test specimens were prepared, sprinkled and cured for 4 weeks after placing concrete, and then exposed to the sea with cracks introduced by tightening at three equal points.
暴露試験場は、静岡県伊東市城が崎の海岸で、最高潮
位より50cm程度上部の荷台に固定した。この場所は常時
海水飛沫を受ける環境である。The exposure test site was fixed on a bed about 50 cm above the highest tide on the coast of Saki in Ito City, Shizuoka Prefecture. This is an environment where seawater is constantly splashed.
試験結果を第２表に示した。鉄粉混入コンクリート梁
（実施例）の鉄筋の腐食は、暴露当初ひび割れを導入し
た部分を中心に発生しており、健全なかぶり部分からの
塩分の侵入によって発生している腐食は認められない。
また、断面における鉄粉自身の腐食は、表面から1mm以
内であった。The test results are shown in Table 2. Corrosion of the reinforcing steel of the concrete beam mixed with iron powder (Example) occurs mainly at the portion where cracks were introduced at the beginning of the exposure, and no corrosion caused by the intrusion of salt from a sound covering portion is observed.
The corrosion of the iron powder itself in the cross section was within 1 mm from the surface.
普通コンクリート梁（比較例）の鉄筋腐食は、全面腐
食に近く断面欠損も大きい。Reinforcement corrosion of ordinary concrete beams (comparative example) is close to general corrosion and has large cross-sectional defects.
実施例２ 第３表に示す配合の普通コンクリート及び本発明に係
る化学的安定物である鉄鉱石細骨材混入コンクリートの
供試体を作製し、促進腐食試験により鉄鉱石細骨材コン
クリートの防食効果を検討した。 Example 2 Specimens of normal concrete having the composition shown in Table 3 and concrete mixed with iron ore fine aggregate, which is a chemical stabilizer according to the present invention, were prepared. It was investigated.
供試体は『コンクリート構造物の腐食・防食に関する
試験方法ならびに基準（案）昭和62年４月10日、JCI−S
C2、「塩分を含んだコンクリート中における補強用鋼棒
の促進腐食試験方法」（オートクレーブ法）』に準じて
作製した。The test specimen was prepared as follows: “Test Method and Standard for Corrosion and Corrosion Protection of Concrete Structures (Draft) April 10, 1987, JCI-S
C2, "Accelerated corrosion test method of reinforcing steel bar in concrete containing salt" (autoclave method).
混入塩分量はCl-で5kg/m3とし、CaCl2で7.85kg/m3を
コンクリートの混練り水に添加した。Mixed amount of salt is Cl - and 5 kg / m 3 in, and the 7.85 kg / m 3 in CaCl 2 was added to the kneading water concrete.
鉄筋は直径13mm、長さ160mmの磨き丸鋼（高炉品）を
用いた。鉄筋のかぶりは1cmと2cmとした。供試体は同一
条件につき２本作製した。コンクリートは打設後密封養
生して７日後にオートクレーブ試験に供した。The reinforcing steel used was a polished round steel (blast furnace product) with a diameter of 13 mm and a length of 160 mm. The cover of the rebar was 1 cm and 2 cm. Two specimens were prepared under the same conditions. The concrete was sealed and cured after casting, and was subjected to an autoclave test 7 days later.
オートクレーブの条件としては、上昇温度は２℃／分
とし、180℃にて８時間保持したのち自然冷却した。The autoclave was heated at a rate of 2 ° C./min, kept at 180 ° C. for 8 hours, and then cooled naturally.
試験結果を第４表、第５表及び第１図に示した。CaCl
2を含まないものは腐食が見られなかったが、CaCl2を含
むものは腐食した。しかし実施例の鉄鉱石細骨材コンク
リートは、腐食面積率でほぼ10分の１の腐食量であっ
た。第１図はこれを棒グラフで示したもので、本発明の
効果は明白である。The test results are shown in Tables 4, 5 and 1. CaCl
No corrosion was observed in those containing no 2 , whereas those containing CaCl 2 corroded. However, the iron ore fine aggregate concrete of the example had a corrosion amount of about 1/10 in the corrosion area ratio. FIG. 1 shows this in a bar graph, and the effect of the present invention is clear.
〔発明の効果〕 本発明によれば、RC構造物中の鉄筋は、防食性に優れ
ており、特に長期的にすぐれた防食性を示す。本発明は
安定的に材料を供給することができ、コンクリートの施
工（製造）が容易であり、低コストで大きな効果を奏す
る。 [Effects of the Invention] According to the present invention, the reinforcing steel in the RC structure has excellent anticorrosion properties, and particularly exhibits excellent anticorrosion properties over a long period of time. ADVANTAGE OF THE INVENTION This invention can supply a material stably, the construction (manufacturing) of concrete is easy, and it has a large effect at low cost.
第１図は本発明の効果を示す棒グラフである。 FIG. 1 is a bar graph showing the effect of the present invention.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 星野 富夫 千葉県千葉市弥生町１―170 東大西千 葉宿舎３―104 (72)発明者 辻 恒平 茨城県水戸市元石川町611―207 (56)参考文献 特開 昭61−247670（ＪＰ，Ａ) 特開 昭48−47527（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) C23F 11/00,11/18,15/00 C04B 14/34,14/48,22/04 E04B 1/64──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomio Hoshino 1-170 Yayoi-cho, Chiba-shi, Chiba 3-104, Chiba-Higashionishi 3-72 (72) Inventor Kohei Tsuji 611-207, Motoishikawa-cho, Mito-shi, Ibaraki-ken References JP-A-61-247670 (JP, A) JP-A-48-47527 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) C23F 11/00, 11/18, 15/00 C04B 14 / 34,14 / 48,22 / 04 E04B 1/64
Claims (1)
中に、鉄分を含みコンクリート中で化学的に安定な化学
的安定物を混入し、塩化物イオンのコンクリート中への
浸入に対する鉄筋の腐食反応を抑制することを特徴とす
るRC構造物の鉄筋防食方法。(1) At the time of placing concrete, a chemical stabilizer containing iron and chemically stable in the concrete is mixed into the ordinary concrete, thereby suppressing a corrosion reaction of the reinforcing steel bar when chloride ions enter the concrete. Corrosion protection method for RC structures characterized by the following.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2088134A JP2809805B2 (en) | 1990-04-04 | 1990-04-04 | Corrosion protection method for RC structures |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2088134A JP2809805B2 (en) | 1990-04-04 | 1990-04-04 | Corrosion protection method for RC structures |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03287792A JPH03287792A (en) | 1991-12-18 |
| JP2809805B2 true JP2809805B2 (en) | 1998-10-15 |
Family
ID=13934459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2088134A Expired - Fee Related JP2809805B2 (en) | 1990-04-04 | 1990-04-04 | Corrosion protection method for RC structures |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2809805B2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5227169B2 (en) * | 1971-10-20 | 1977-07-19 | ||
| JPS61247670A (en) * | 1985-04-24 | 1986-11-04 | 同和鉱業株式会社 | Heavy concrete |
-
1990
- 1990-04-04 JP JP2088134A patent/JP2809805B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03287792A (en) | 1991-12-18 |
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