Mechanisms of Combined Effects of AAR and Reinforcement Corrosion on Concrete

AAR与钢筋腐蚀对混凝土的联合作用机理

• 批准号: 08650530
• 负责人: KAWAMURA Mitsunori
• 金额: $ 1.41万
• 依托单位: KANAZAWA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650530/
• 关键词: Sodium Nitrite; Calcium Nitrite; Ettringite; Corrosion; Steel Bar; ASR Gel; Interfacial Transiiton Zone; Sulfate Ion; 海水; 塩化ナトリウム溶液; ブルーサイト; アラゴナイト; アルカリシリカ反応; 鉄筋腐食; 複号劣化機構; 塩分環境; 電気化学的測定; 実態調査; 融雪・融氷剤

We could propose a new thought on the mechanisms of the promotion of ASR due to sodium chloride and sea water through detailed experiments concerning the effects of externally supplied sea water and sodium chloride solution on ASR and the process of ASR chemical reaction in mortars with and without NaCl. Furthermore, the changes in pore solution composition with time at various depths from the surfaces of specimens and their relation to the corrosion of reinforcement steel bars in the specimens were elucidated. Another important result was a finding on the relation between the effectiveness of nitrites and the pore solution composition in mortars containing the nitrites.The major results obtained were summarized as follows ;(1) The Cl-/OH- ratios in mortars in 0.51Mm NaCl solution were greater than in sea water at 360 daysafter, immersion. The formation of dense layrs aragonite and brucite might hinder the intrusion of the Cl- ions into mortar cylinders and the leakage of OH- ions from them.(2) From a point of view of the pore solution composition, far greater corrosion degree in steel bars in reactive. aggregate-containing mortars was unexpected.(3) Replacement of greater amounts of reactive aggregate for standerd sand in mortars resulted in less degree of corrosion in steel bars except one case. The depression of corrosion in reactive aggregate-containing mortars in sea water and NaCl solution appears to result from the formation of homogeneous ASR gel layrs surrounding the steel bars.

通过详细的实验研究了外加海水和氯化钠溶液对砂浆ASR的影响，以及有无NaCl时砂浆中ASR的化学反应过程，为探讨氯化钠和海水促进ASR的机理提供了新的思路。此外，孔溶液的组成随时间的变化，在不同的深度从试样的表面和它们的关系，在试样中的钢筋腐蚀阐明。研究结果表明：（1）砂浆在0.51MNaCl溶液中浸泡360天后，其Cl-/OH-比值大于海水中的Cl-/OH-比值;致密层文石和水镁石的形成可能会阻碍Cl-离子侵入砂浆柱体和OH-离子从砂浆柱体中漏出。(2)从孔隙溶液成分的角度来看，腐蚀程度远大于钢筋中的反应性。含有聚合物的迫击炮是出乎意料的。(3)用活性骨料代替砂浆中的标准砂，除一种情况外，钢筋的腐蚀程度较低。在海水和NaCl溶液中的反应性骨料砂浆腐蚀的抑郁症似乎是由于形成均匀的ASR凝胶层周围的钢筋。

项目成果

Kuwamura, M.and Takeuchi, K.: "Alkali-Silica Reaction and Pore Solution Composition in mortars in Sea Water" An International Journal of Cement and Concrete Research. Vol.26, No.12. 1809-1820 (1996)

Kuwamura, M. 和 Takeuchi, K.：“海水砂浆中的碱硅反应和孔隙溶液组成”国际水泥和混凝土研究杂志。

Kawamura, M., Tanikawa, S., Swamy, R.N.and Koto, H.: "Pore Solution Composition and Electrochemical Behavior of Steel Bars in Mortars with Nitrite Corrosion Inhibitors" Americal Concrete Institution, Special Publication. 173. 35-53 (1997)

Kawamura, M.、Tanikawa, S.、Swamy, R.N. 和 Koto, H.：“含有亚硝酸盐腐蚀抑制剂的砂浆中钢筋的孔隙溶液组成和电化学行为”美国混凝土学会，特别出版物。

M.Kawamura, S.Tanikawa R.N.Swamy, H.Koto: "Pore Solution Composition and Electrochemical Behavior of Steel Barsin Mortars with Nitrite Corrosion Inhibitors" Proc.of FIFTH CANMET/ACI Conf.on Superplasticizers and other Chemical Admixtures in Concrete. 35-5

M.Kawamura、S.Tanikawa R.N.Swamy、H.Koto：“含亚硝酸盐腐蚀抑制剂的钢筋砂浆的孔溶液组成和电化学行为”第五届 CANMET/ACI 会议关于混凝土中超增塑剂和其他化学外加剂的会议记录。

Kuwamura, M.and Komatsu, S.: "Behavior of Various Ions in Pore Solution in NaCl-Bearing Mortar With and Without Reactive Aggregate at Early Ages" An International Journal of Cement and Concrete Research. Vol.27, No.1. 29-36 (1997)

Kuwamura, M. 和 Komatsu, S.：“早期含和不含反应骨料的含 NaCl 砂浆中孔隙溶液中各种离子的行为”国际水泥和混凝土研究杂志。

M.Kwamura D.Singhal Y.Tuji: "Effects of ASR on Corrosion of Reinforcement in Concrete under Saline Environments" Proc.of East Asia Alkali-Aggreg ate Reaction Seminar. 179-190 (1997)

M.Kwamura D.Singhal Y.Tuji：“ASR 对盐环境下混凝土钢筋腐蚀的影响”东亚碱骨料反应研讨会论文集。