Leaching and penetration mechanism of nitrite ions on the surface of concrete and the effects of various factors

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K18098
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Civil engineering materials/Construction/Construction management
• Research Institution: Kitami Institute of Technology
• Principal Investigator: Inoue Masumi 北見工業大学, 工学部, 准教授 (00388141)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 亜硝酸イオン / 溶脱 / 浸透 / 補修 / 排出基準

Outline of Final Research Achievements

This study aimed to clarify the leaching and penetration properties of nitrite ions in nitrite-type repair materials exposed to rainfall. Repaired concrete specimens were prepared for leaching and penetration tests using a lithium nitrite solution, and the amounts of leaching and penetration of nitrite ions were measured under simulated rainfall and real site.
As a result, it was confirmed that the nitrite ion concentration in all repair methods changed at approximately cycle 10. And the nitrite ion leaching can be controlled using cement paste and cement mortar surface coatings with the addition of nitrite solution and surface coating by mortar after direct coating with the nitrite solution. Furthermore, the nitrite ion leaching amounts of all repair methods in all cycles were smaller than that of the discharge standard value (329ppm).

Free Research Field

コンクリート工学