JPH028383A - Back filler for electrolytic protection - Google Patents
Back filler for electrolytic protectionInfo
- Publication number
- JPH028383A JPH028383A JP63158484A JP15848488A JPH028383A JP H028383 A JPH028383 A JP H028383A JP 63158484 A JP63158484 A JP 63158484A JP 15848488 A JP15848488 A JP 15848488A JP H028383 A JPH028383 A JP H028383A
- Authority
- JP
- Japan
- Prior art keywords
- anode
- backfill
- sulfate
- concrete
- parts
- 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.)
- Granted
Links
- 239000000945 filler Substances 0.000 title abstract 3
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 claims abstract description 42
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 claims abstract description 22
- 229910001629 magnesium chloride Inorganic materials 0.000 claims abstract description 21
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 claims abstract description 20
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims abstract description 11
- 229910052943 magnesium sulfate Inorganic materials 0.000 claims abstract description 11
- 235000019341 magnesium sulphate Nutrition 0.000 claims abstract description 11
- YKTSYUJCYHOUJP-UHFFFAOYSA-N [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] Chemical compound [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] YKTSYUJCYHOUJP-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052938 sodium sulfate Inorganic materials 0.000 claims abstract description 10
- 235000011152 sodium sulphate Nutrition 0.000 claims abstract description 10
- 229910052751 metal Inorganic materials 0.000 claims abstract description 8
- 239000002184 metal Substances 0.000 claims abstract description 8
- 238000004210 cathodic protection Methods 0.000 claims description 17
- 238000005260 corrosion Methods 0.000 claims description 9
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 5
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 claims description 2
- 230000005611 electricity Effects 0.000 claims 1
- 229910000831 Steel Inorganic materials 0.000 abstract description 15
- 239000010959 steel Substances 0.000 abstract description 15
- 239000002689 soil Substances 0.000 abstract description 8
- 235000011147 magnesium chloride Nutrition 0.000 abstract description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 3
- 239000007832 Na2SO4 Substances 0.000 abstract description 2
- 229910052925 anhydrite Inorganic materials 0.000 abstract description 2
- 230000002633 protecting effect Effects 0.000 abstract description 2
- 150000003467 sulfuric acid derivatives Chemical class 0.000 abstract description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract 1
- 229910052593 corundum Inorganic materials 0.000 abstract 1
- 229910001845 yogo sapphire Inorganic materials 0.000 abstract 1
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 7
- 239000000440 bentonite Substances 0.000 description 7
- 229910000278 bentonite Inorganic materials 0.000 description 7
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 7
- 239000001110 calcium chloride Substances 0.000 description 7
- 229910001628 calcium chloride Inorganic materials 0.000 description 7
- 230000007797 corrosion Effects 0.000 description 7
- 239000010440 gypsum Substances 0.000 description 7
- 229910052602 gypsum Inorganic materials 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 150000001805 chlorine compounds Chemical class 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 235000011132 calcium sulphate Nutrition 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 239000012024 dehydrating agents Substances 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000010446 mirabilite Substances 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Landscapes
- Prevention Of Electric Corrosion (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は電気防食に用いるバックフィルに関し、特に高
抵抗環境、例えばコンクリートあるいは土壌中にある鉄
鋼構造物の電気防食を行うに際し、陽極周辺の抵抗率の
低減と長期に亘って保水性を確保するためのバックフィ
ルに関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a backfill used for cathodic protection, particularly when performing cathodic protection of steel structures in high resistance environments such as concrete or soil. Related to backfill for reducing resistivity and ensuring water retention over a long period of time.
従来、土壌、淡水等の比較的高抵抗率の電解質環境中に
ある金属構造物を電気防食する場合、陽極周辺の抵抗が
高いため、外部電源方式では浴電圧の上昇が避けられず
、また流電陽極方式では防食に必要な陽極発生電流が過
小となり、長期に亘り陽極と金属構造物との有効な電位
差を保持することが難しく、所要の防食電流を維持する
ことが困難になることが多い。Conventionally, when cathodic protection is applied to metal structures in relatively high-resistivity electrolyte environments such as soil or fresh water, the resistance around the anode is high, so using an external power supply method inevitably increases the bath voltage, and the current In the electrode anode method, the anode generated current required for corrosion protection is too small, making it difficult to maintain an effective potential difference between the anode and the metal structure over a long period of time, and it is often difficult to maintain the required corrosion protection current. .
このため、タンク底抜や埋設管の如く土壌環境を対象と
した電気防食に際して、陽極周辺にベントナイト、石膏
および芒硝等からなるバックフィルを充填して陽極の抵
抗率の低減や陽極の不活性化を防止する手段がとられて
いる。このバックフィルは設置にあたって初めから水分
を含有させるか、あるいは環境から水分を取り入れ、そ
の後は長期に亘って保水性を維持することが重要である
。従って、陽極に接する周辺環境が著しい乾燥状態であ
ると、バックフィルに取り込まれた水分が周辺環境に逸
散し、バックフィルの抵抗率の増大をきたし、その結果
、陽極の分極（資化）を起こし、発生電流の低減や浴電
圧の増大等を促進し、陽極性能が不安定化し、満足し得
る結果が期待できない場合がある。For this reason, when performing cathodic protection for soil environments such as tank bottom removal and buried pipes, a backfill made of bentonite, gypsum, mirabilite, etc. is filled around the anode to reduce the resistivity of the anode and to inactivate the anode. Measures are being taken to prevent this. It is important that this backfill contains moisture from the beginning when it is installed, or that it takes in moisture from the environment, and that it maintains its water retention properties over a long period of time. Therefore, if the surrounding environment in contact with the anode is extremely dry, the moisture taken into the backfill will dissipate into the surrounding environment, causing an increase in the resistivity of the backfill and, as a result, polarization (assimilation) of the anode. This may cause a reduction in the generated current, an increase in the bath voltage, etc., and the anode performance may become unstable, making it impossible to expect a satisfactory result.
また、土壌等以外の高抵抗環境としてコンクリートが挙
げられる。すなわちコンクリートで覆われた鉄鋼構造物
を電気防食する場合である。Furthermore, concrete is an example of a high resistance environment other than soil. This is the case when cathodic protection is applied to steel structures covered with concrete.
コンクリートは従来から難透水性でしかもアルカリ環境
であるということから、鉄筋や鋼管杭等のコンクリート
被覆鉄鋼構造物の腐食はほとんど無視されていた。しか
しながら、コンクリート成分である在来の砂、砂利に含
まれる塩化物や環境から外来の海水飛沫等の塩化物が溶
解した水分となって徐々にコンクリート中に浸透し、コ
ンクリートの中性化を促し、やがては鉄鋼構造物が腐食
環境にさらされる。その結果、塩化物イオンが鋼表面の
保護皮膜を破壊し、鉄鋼の腐食の進行とともにコンクリ
ート内部において腐食性成物が増量し、コンクリート構
造物のひび割れや破壊が起こる。現実に、橋梁、橋桁、
床版、鋼杭等の港湾コンクリート施設は半永久的施設と
いわれていながら１０〜２０年で取替えの必要性に迫ら
れているのが現状である。これらの既設コンクリート鉄
鋼構造物の防食は電気防食法が唯一の手段である。電気
防食には外部電源方式であれ、流電陽極方式であれ、陽
極からの防食電流を通す電解質の存在が不可欠である。Concrete has traditionally been poorly permeable and has an alkaline environment, so corrosion of concrete-coated steel structures such as reinforcing bars and steel pipe piles has been largely ignored. However, chlorides contained in the native sand and gravel that are concrete components, as well as chlorides from foreign seawater splashes from the environment, gradually penetrate into the concrete as dissolved water, promoting the neutralization of the concrete. Eventually, steel structures will be exposed to corrosive environments. As a result, chloride ions destroy the protective film on the steel surface, and as the corrosion of the steel progresses, the amount of corrosive compounds inside the concrete increases, causing cracks and destruction of the concrete structure. In reality, bridges, bridge girders,
Although port concrete facilities such as deck slabs and steel piles are said to be semi-permanent facilities, the current situation is that they need to be replaced every 10 to 20 years. Cathodic protection is the only means of corrosion protection for these existing concrete and steel structures. For cathodic protection, whether using an external power supply method or a galvanic anode method, the presence of an electrolyte that conducts the protective current from the anode is essential.
換言すると水分の存在が絶対要件である。In other words, the presence of moisture is an absolute requirement.
一般にコンクリートの導電性は極めて小さく、水分の存
在が大きく影響する。その抵抗率は数千Ω・１から数十
万Ω・■にわたっており、このようなコンクリートの導
電性を高めることは容易ではない。従って、電気防食の
効果を有効ならしめるためにはこのような環境下におけ
る陽極の性能、すなわち陽極分極や陽極不活性を最小限
に抑えることが必要である。Generally, the conductivity of concrete is extremely low, and the presence of moisture has a large effect. Its resistivity ranges from several thousand Ω·1 to several hundreds of thousands of Ω·■, and it is not easy to improve the conductivity of such concrete. Therefore, in order to make the effect of cathodic protection effective, it is necessary to minimize the performance of the anode under such an environment, that is, the anodic polarization and anode inactivity.
その手段としてはバックフィルで陽極周辺を囲んで陽極
の接地抵抗を下げ陽極から十分に電流を発生させること
が考えられる。しかしながら、前述したような従来から
土壌環境中で使用されていたバックフィルは保水性に難
点があり、コンクリート鉄鋼構造物の電気防食用バック
フィルとして充分な保水性が期待できないという問題点
を有するものであった。One possible means for this is to surround the anode with a backfill to lower the grounding resistance of the anode and to generate sufficient current from the anode. However, the backfill conventionally used in soil environments as described above has a problem in water retention, and it cannot be expected to have sufficient water retention as a backfill for cathodic protection of concrete and steel structures. Met.
そこで本発明では、■コンクリートあるいは土壌の如き
高抵抗環境中にある鉄鋼構造物を電気防食するに際し、
陽極からの防食電流が安定かつ長期に亘って維持できる
バックフィルを提供すること、■長期に亘って陽極の接
地抵抗を低く保ち、特に保水性を高めたバックフィルを
提供すること、■保水性物質が入手容易で安価なバック
フィルの構成物質を見い出すことを目的とするものであ
る。Therefore, in the present invention, (1) When electrolytically protecting a steel structure in a high resistance environment such as concrete or soil,
To provide a backfill that can maintain a stable anti-corrosion current from the anode over a long period of time; ■ To provide a backfill that maintains low grounding resistance of the anode over a long period of time and has particularly high water retention; ■ Water retention. The objective is to find constituent materials for backfill that are easily available and inexpensive.
本発明はケイ酸アルミニウム永和物、金属硫酸塩および
塩化マグネシウムからなる電気防食用バックフィルによ
り、上記課題を達成したものである。The present invention has achieved the above-mentioned problems by using a cathodic protection backfill consisting of aluminum silicate permanent, metal sulfate, and magnesium chloride.
本発明における金属硫酸塩としては、硫酸カルシウム単
独か、あるいは硫酸カルシウムと、硫酸マグネシウム、
硫酸ナトリウム、硫酸アルミニウムから選ばれるいずれ
か１種からなる。The metal sulfate in the present invention includes calcium sulfate alone, calcium sulfate and magnesium sulfate,
Consists of one selected from sodium sulfate and aluminum sulfate.
このような本発明の好ましいバックフィル組成としては
、ケイ酸アルミニウム水和物、硫酸カルシウム、硫酸マ
グネシウムまたは硫酸ナトリウム、および塩化マグネシ
ウムからなるものが挙げられる。Such preferred backfill compositions of the present invention include those consisting of aluminum silicate hydrate, calcium sulfate, magnesium sulfate or sodium sulfate, and magnesium chloride.
そして、上記のような組成からなるバックフィルの組成
比は、ケイ酸アルミニウム水和物：硫酸カルシウム：硫
酸マグネシウムまたは硫酸ナトリウム：塩化マグネシウ
ムの重量比を、６〜８：１〜３：０〜３：２〜６とし、
より好ましくはその比を、７：２：１：３〜５とする。The composition ratio of the backfill having the above composition is such that the weight ratio of aluminum silicate hydrate:calcium sulfate:magnesium sulfate or sodium sulfate:magnesium chloride is 6 to 8:1 to 3:0 to 3. :2 to 6,
More preferably, the ratio is 7:2:1:3-5.
ケイ酸アルミニウム水和物（ＡＱ２０３ｍｓｉｏ２・ｎ
Ｈ２Ｏ）であるベントナイトはバックフィルの主成分で
あり、水分を長期に亘って保持する効果と接地抵抗低減
効果を有している。そして石膏（ＣａＳＯ４・２Ｈ２０
）や芒硝（Ｎａ２ＳＯ４）等の硫酸塩はバックフィルの
抵抗率の低減と保水性維持に有効である。しかし、これ
らの成分は長期的乾燥状態が続くと環境中に水分を逸散
し、その結果バックフィルの抵抗率が高まるとともに陽
極の分極をすすめ、発生電流の低減や浴電圧の増大を促
し、陽極の性能が不安定になる。これに対し、本発明に
おけるように、これら成分に塩化マグネシウムを添加す
ると、この塩化マグネシウムにより乾燥状態が長期に亘
っても水分の逸散を抑制し、また水分を吸収しやすくす
るため、前述の陽極性能を不安定にする要因が抑制され
る結果、極めて安定した陽極性能を長期に亘って維持す
る作用をなす。この塩化マグネシウムは通常入手が容易
であるとともに安価である。Aluminum silicate hydrate (AQ203msio2・n
Bentonite (H2O) is the main component of the backfill, and has the effect of retaining moisture for a long period of time and the effect of reducing ground resistance. and gypsum (CaSO4・2H20
) and sulfates such as sodium sulfate (Na2SO4) are effective in reducing the resistivity of backfill and maintaining water retention. However, if these components remain dry for a long period of time, they will dissipate moisture into the environment, increasing the resistivity of the backfill and polarizing the anode, reducing the generated current and increasing the bath voltage. Anode performance becomes unstable. On the other hand, when magnesium chloride is added to these components as in the present invention, this magnesium chloride suppresses the loss of moisture even if the dry state lasts for a long period of time, and also makes it easier to absorb moisture. As a result of suppressing the factors that make the anode performance unstable, it has the effect of maintaining extremely stable anode performance over a long period of time. This magnesium chloride is usually easily available and inexpensive.
なお、この塩化マグネシウムに代えて塩化カルシウムを
添加することも考えられるが、塩化カルシウムは脱水剤
としては有効であるものの、保水性の点では充分でない
。すなわち、乾燥状態の環境中にあっても水分を長期に
亘って保持するという点では有効ではない。このように
塩化マグネシウムは保水性の点で塩化カルシウムとは大
きな差異を有するものであり、バックフィル添加物とし
ての作用は塩化カルシウムによって代替できるものでな
い。It is possible to add calcium chloride instead of magnesium chloride, but although calcium chloride is effective as a dehydrating agent, it is not sufficient in terms of water retention. That is, it is not effective in retaining moisture for a long period of time even in a dry environment. As described above, magnesium chloride has a large difference from calcium chloride in terms of water retention, and its function as a backfill additive cannot be replaced by calcium chloride.
以下に実施例を示す。Examples are shown below.
実施例
鉄板（１，００Ｘ ７０ Ｘ ０．５ｍｍ）を埋設した
モルタル（かぶり厚さ７ｃｍ）の表面にバックフィルを
介して亜鉛の板状陽極を固定した供試体を作製し、モル
タル中の鉄板を対極として１０μＡ／ａｎ？の定電流ア
ノード電解を行った。Example A specimen was prepared in which a zinc plate anode was fixed to the surface of a mortar (cover thickness 7 cm) in which an iron plate (1,00 x 70 x 0.5 mm) was embedded via a backfill. 10 μA/an as a counter electrode? Constant current anodic electrolysis was performed.
バックフィルは、■ベントナイト、石膏、硫酸マグネシ
ウム（重量比で７：２：１）の混合系、■ベントナイト
、石膏、硫酸マグネシウム、塩化カルシウム（７： ２
： １ ： ４）の混合系、■ベントナイト、石膏、
硫酸マグネシウム、塩化マグネシウム（７： ２ ：
１ ： ４）の混合系、■ベントナイト、石膏、塩化マ
グネシウム（７：２＝４）の混合系の４種類のものを用
いた。The backfill is: ■ A mixed system of bentonite, gypsum, and magnesium sulfate (7:2:1 by weight); ■ Bentonite, gypsum, magnesium sulfate, and calcium chloride (7:2)
: 1 : 4) mixture system, ■bentonite, gypsum,
Magnesium sulfate, magnesium chloride (7: 2:
Four types were used: a mixed system of 1:4), and a mixed system of bentonite, gypsum, and magnesium chloride (7:2=4).
これら各混合系バックフィルを用いた場合の陽極電位を
経時的に測定した結果を第１図に示す。この第１図から
れかるように、塩化マグネシウム含有バックフィル■、
■を介した供試体は陽極電位が長期間に亘って陽分極も
なく卑電位で安定しており、従来例■および塩化カルシ
ウム含有のバックフィル■と比較して、塩化マグネシウ
ム含有バックフィルは性能が格段に優れているものであ
った。FIG. 1 shows the results of measuring the anode potential over time when each of these mixed backfills was used. As shown in Fig. 1, backfill containing magnesium chloride ■,
The anodic potential of the test sample through ■ remained stable at a base potential without positive polarization for a long period of time, and compared to the conventional example ■ and the backfill containing calcium chloride ■, the backfill containing magnesium chloride had better performance. was significantly superior.
次に、各供試体のアノード、カソードを導通させて、防
食電流を発生させた場合の電流（電流密度）を測定した
結果を第２図に示す。この第２図から明らかなように本
発明による塩化マグネシウム含有バックフィル■および
■を介した供試体は従来例■および塩化カルシウム含有
バックフィル■の場合と比較して発生電流が大きく、こ
のバックフィル系が高性能であることを示している。Next, FIG. 2 shows the results of measuring the current (current density) when the anode and cathode of each specimen were brought into conduction to generate a corrosion protection current. As is clear from FIG. 2, the specimens using the magnesium chloride-containing backfills (■) and (2) according to the present invention generate a larger current than the conventional example (■) and the calcium chloride-containing backfill (■). This shows that the system has high performance.
また、広口の１００ｍ１ビーカーに４種の系の混合物を
入れて、一定水分を含浸させ、恒温恒湿槽（温度２５℃
一定）に入れ、３０％、５０％、７０％、９０％の湿度
に設定して、それぞれ７日間放置した。恒湿設定前後の
重量を測定したところ、第３図に示す結果が得られた。In addition, a mixture of four types of systems was placed in a wide-mouthed 100 m1 beaker, impregnated with a certain amount of moisture, and placed in a constant temperature and humidity bath (temperature 25°C).
The humidity was set at 30%, 50%, 70%, and 90%, respectively, and left for 7 days. When the weight was measured before and after the humidity was set, the results shown in FIG. 3 were obtained.
この第３図かられかるように、塩化マグネシウム含有混
合物は水分の逸散が小さくバックフィルとして優れたも
のであるといえる。As can be seen from FIG. 3, it can be said that the magnesium chloride-containing mixture exhibits little water loss and is excellent as a backfill.
以上のように本発明によれば、従来から広く用いられて
きたベントナイト、石膏、硫酸マグネシウム（硫酸ナト
リウム）からなるバックフィルに安価で入手容易な塩化
マグネシウムを添加混合しているため、乾燥状態が長期
に亘っても水分の逸脱を抑制し、また水分を吸収しやす
くするため、極めて安定した陽極性能を長期に亘って維
持でき、土壌環境中のみならずコンクリート環境中の鉄
鋼構造物の電気防食に使用するに好適なバックフィルが
得られる。As described above, according to the present invention, inexpensive and easily available magnesium chloride is added to and mixed with the backfill consisting of bentonite, gypsum, and magnesium sulfate (sodium sulfate), which have been widely used in the past, so that dry conditions are reduced. By suppressing moisture leakage and making it easier to absorb moisture over a long period of time, extremely stable anode performance can be maintained over a long period of time, making it suitable for cathodic protection of steel structures not only in soil environments but also in concrete environments. A backfill suitable for use is obtained.
第１図は実施例における各供試体の陽極電位の経時変化
を示す関係図である。
第２図は実施例における各供試体の電流密度の経時変化
を示す関係図である。
第３図は実施例における各供試体の温度一定で湿度を変
えた場合の重量変化を示す関係図である。
特許出願人 中川防蝕工業株式会社FIG. 1 is a relationship diagram showing changes over time in the anode potential of each specimen in Examples. FIG. 2 is a relationship diagram showing changes over time in the current density of each specimen in the example. FIG. 3 is a relationship diagram showing the weight change when the temperature of each specimen in the example is constant and the humidity is changed. Patent applicant Nakagawa Corrosion Industry Co., Ltd.
Claims (1)
マグネシウムからなる電気防食用バックフィル。 ２、金属硫酸塩が硫酸カルシウムと、硫酸マグネシウム
、硫酸ナトリウム、硫酸アルミニウムから選ばれるいず
れか１種とからなる請求項１記載の電気防食用バックフ
ィル。 ３、金属硫酸塩が硫酸カルシウムからなる請求項１記載
の電気防食用バックフィル ４、ケイ酸アルミニウム水和物、硫酸カルシウム、硫酸
マグネシウムおよび塩化マグネシウムからなる請求項１
記載の電気防食用バックフィル。 ５、ケイ酸アルミニウム水和物、硫酸カルシウム、硫酸
ナトリウムおよび塩化マグネシウムからなる請求項１記
載の電気防食用バックフィル。 ６、重量比で、ケイ酸アルミニウム水和物：硫酸カルシ
ウム：硫酸マグネシウムまたは硫酸ナトリウム：塩化マ
グネシウムが６〜８：１〜３：０〜３：２〜６である請
求項３または４記載の電気防食用バックフィル。 ７、前記重量比が、７：２：１：３〜５である請求項５
記載の電気防食用バックフィル。[Claims] 1. A cathodic protection backfill consisting of aluminum silicate hydrate, metal sulfate and magnesium chloride. 2. The cathodic protection backfill according to claim 1, wherein the metal sulfate comprises calcium sulfate and any one selected from magnesium sulfate, sodium sulfate, and aluminum sulfate. 3. The backfill for cathodic protection according to claim 1, wherein the metal sulfate is composed of calcium sulfate. Claim 1, which is composed of aluminum silicate hydrate, calcium sulfate, magnesium sulfate, and magnesium chloride.
Cathodic protection backfill as described. 5. The cathodic protection backfill according to claim 1, comprising aluminum silicate hydrate, calcium sulfate, sodium sulfate, and magnesium chloride. 6. The electricity according to claim 3 or 4, wherein the weight ratio of aluminum silicate hydrate: calcium sulfate: magnesium sulfate or sodium sulfate: magnesium chloride is 6 to 8:1 to 3:0 to 3:2 to 6. Anti-corrosion backfill. 7. Claim 5, wherein the weight ratio is 7:2:1:3 to 5.
Cathodic protection backfill as described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63158484A JP2711455B2 (en) | 1988-06-27 | 1988-06-27 | Backfill for cathodic protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63158484A JP2711455B2 (en) | 1988-06-27 | 1988-06-27 | Backfill for cathodic protection |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH028383A true JPH028383A (en) | 1990-01-11 |
| JP2711455B2 JP2711455B2 (en) | 1998-02-10 |
Family
ID=15672747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63158484A Expired - Fee Related JP2711455B2 (en) | 1988-06-27 | 1988-06-27 | Backfill for cathodic protection |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2711455B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116641059A (en) * | 2023-05-25 | 2023-08-25 | 水利部交通运输部国家能源局南京水利科学研究院 | A device and method for directional absorption of chloride ions in reinforced concrete |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5969462A (en) * | 1982-10-06 | 1984-04-19 | 川崎重工業株式会社 | Manufacture of hardened body from coal ash |
| JPS6316471A (en) * | 1986-07-08 | 1988-01-23 | Matsushita Electric Ind Co Ltd | Reproducing device for digital data |
-
1988
- 1988-06-27 JP JP63158484A patent/JP2711455B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5969462A (en) * | 1982-10-06 | 1984-04-19 | 川崎重工業株式会社 | Manufacture of hardened body from coal ash |
| JPS6316471A (en) * | 1986-07-08 | 1988-01-23 | Matsushita Electric Ind Co Ltd | Reproducing device for digital data |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116641059A (en) * | 2023-05-25 | 2023-08-25 | 水利部交通运输部国家能源局南京水利科学研究院 | A device and method for directional absorption of chloride ions in reinforced concrete |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2711455B2 (en) | 1998-02-10 |
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