Corrosion factors of underground steel considering reaction/transportation of substances and proposal of countermeasure for the corrosion protection
| Project/Area Number |
20K04657
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Review Section |
Basic Section 22010:Civil engineering material, execution and construction management-related
|
|---|
| Research Institution | Shizuoka Institute of Science and Technology (2022)
National Institute of Maritime, Port and Aviation Technology (2020-2021) |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
河合 慶有 愛媛大学, 理工学研究科(工学系), 准教授 (90725631)
|
|---|
| Project Period (FY) |
2020-04-01 – 2023-03-31
|
| Project Status |
Completed (Fiscal Year 2022)
|
| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2022: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2021: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2020: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
|
|---|
| Keywords | 鋼材腐食 / 土中 / 抑制方法 / アノード / カソード / 酸素低減 / 反応 / 物質移動 / 腐食対策 |
|---|
| Outline of Research at the Start |
一般に，土中では，陸上や海中と比較して腐食の進行が遅いが，容易に点検・検査が難く，長期間放置しておくと甚大な被害が生じる．一方で，近年，地中構造物の需要は増加の一途をたどっている．本研究では(a)遊具や道路標識などの支柱，(b)無電中化などで埋設される電線類や管路，さらには，(c)放射性廃棄物の地層処分に使用される鋼材などを対象とし，土中の鋼材腐食対策方法の確立に成果の反映を図る．以下に目的を示す．
目的(1) 土中での鋼材腐食の進行速度に及ぼす要因の抽出
目的(2) 目的(1)で抽出された要因を踏まえた腐食の対策方法の確立
|
| Outline of Final Research Achievements |
In this study, electrochemical parameters such as polarisation resistance and natural potential of steel buried in soil were measured through exposure tests. As a result, it was confirmed that the corrosion rate increased once in the early stage of exposure and then decreased. However, in the case of sand, no significant increase in corrosion rate was observed when the steel was installed at the bottom. These results suggest that the corrosion of steel in soil is strongly influenced by oxygen and that corrosion can be reduced by reducing oxygen. In particular, steel in clay tends to develop macrocell corrosion due to changes in oxygen permeability, and this study investigated techniques to prevent localised corrosion of underground steel and found the use of oxygen reducing agents to be effective.
|
| Academic Significance and Societal Importance of the Research Achievements |
本研究では，種々のパラメータを勘案し，カソード反応がアノード反応に及ぼす影響を考慮し，酸素や水の土中での移動速度を関連付けて評価した．また，コンクリート中鋼材を対象として，内部の酸素低減による鉄筋腐食の抑制について検討を進めており，工業副産物や微生物に基づいた技術の特許申請をしている．本研究ではこれらの知見を応用し，酸素低減可能な材料を散布することにより土中の酸素量を低減することを試みた．このような検討はこれまで見当たらず，この点が本研究の独創性である．
|
Report
(4 results)
Research Products
(9 results)
