硅酸盐学报

高地热环境多因素影响混凝土模拟孔溶液中钢筋腐蚀行为

PDF下载

王艳 ¹^,³ , 吴杰 ¹ , 张少辉 ¹ , 牛荻涛 ²^,³

硅酸盐学报 | 研究论文 2024,52(11): 3583-3593

收起

硅酸盐学报 |研究论文 2024 , 52 (11) : 3583 -3593

高地热环境多因素影响混凝土模拟孔溶液中钢筋腐蚀行为

全屏

王艳¹^,³, 吴杰¹, 张少辉¹, 牛荻涛²^,³

作者信息

^1．西安建筑科技大学材料科学与工程学院，西安 710055

^2．西安建筑科技大学土木工程学院，西安 710055

^3．绿色建筑全国重点实验室，西安建筑科技大学，西安 710055

作者简介:

王艳（1982—），女，博士，教授。

Corrosion Behavior of Steel Bars in Simulated Pore Solution of Concrete Under High Geothermal Environment

Yan WANG¹^,³, Jie WU¹, Shaohui ZHANG¹, Ditao NIU²^,³

Affiliations

^1.College of materials science and engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China

^2.School of civil engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China

^3.State Key Laboratory of Green Building in Western China, Xi'an University of Architecture and Technology, Xi'an 710055, China

WANG Yan (1982-), female, Ph.D., Professor. E-mail: wangyanwjx@126.com

出版时间: 2024-11-20 doi: 10.14062/j.issn.0454-5648.20230879

文章导航

摘要

收起

高地热环境隧道衬砌混凝土中温度、孔溶液pH值、侵蚀离子的共同作用引发钢筋锈蚀。通过模拟混凝土孔隙液，研究了环境温度（20 ℃和60 ℃）、孔溶液pH值（12.55、12.15、11.75）和侵蚀离子种类（Cl^-、SO₄^2-和Cl^-、SO₄^2-复合）共同作用下，钢筋开始锈蚀的临界离子浓度及其锈蚀行为。结果表明：氯盐侵蚀时，温度为60 ℃、pH值为12.55的饱和混凝土模拟液中，钢筋锈蚀的临界氯离子浓度为0.04~0.06 mol/L；当pH值降低到12.15和11.75时，钝化膜稳定性下降，临界氯离子浓度降低到0.03~0.05 mol/L和0.02~0.04 mol/L。硫酸盐侵蚀钢筋的锈蚀诱导期更长，温度为60 ℃、pH值为12.55、12.15时，钢筋锈蚀的硫酸根浓度阈值相差不大，在0.06~0.08 mol/L之间；当pH值降低到11.75时，硫酸根离子浓度阈值为0.05~0.08 mol/L。硫酸盐与模拟孔溶液中Ca（OH）₂的反应生成石膏，其覆盖在钢筋表面对钢筋锈蚀有延缓作用，因此温度与pH值对SO₄^2-引起的锈蚀浓度阈值影响较小。Cl^-、SO₄^2-复合作用下，SO₄^2-会排斥吸附在电极表面的Cl^-，并与Ca²⁺反应生成CaSO₄，覆盖在钢筋表面使钝化膜致密，延缓了钢筋锈蚀速度。pH值为12.55、12.15时，SO₄^2-分别达到0.03 mol/L和0.04 mol/L时对Cl^-引起的钢筋腐蚀具有缓蚀作用，然而当pH值为11.75时，SO₄^2-对Cl^-引起的钢筋腐蚀无缓蚀作用。

关键词

高地热环境 / 钢筋锈蚀 / 高温 / 孔溶液pH值 / 氯盐-硫酸盐侵蚀。

Abstract

收起

Introduction

The corrosion of steel bar in tunnel lining concrete under high geothermal environment is the result of the combined effect of temperature, pH value of pore solution, and erosion ions. In this paper, the critical ion concentration and corrosion behavior of steel bar under the combined action of ambient temperature (20 ℃ and 60 ℃), pH value of pore solution (12.55, 12.15, and 11.75) and erosion ions (Cl^-, SO₄^2-, and Cl^-, SO₄^2- composite) were studied by simulating concrete pore solution. The results show that the critical chloride concentration of steel corrosion is 0.04-0.06 mol/L in the saturated concrete simulated solution with temperature of 60 ℃ and pH of 12.55 during chloride corrosion. The stability of the passivation film decreased when the pH value decreased (12.15 and 11.75), and the corresponding critical chloride ion concentration also decreased (0.03-0.05 mol/L and 0.02-0.04 mol/L, respectively). The corrosion induction period of steel bar becomes longer when the steel bar is eroded by single sulfate. The threshold value of sulfate ion concentration is between 0.06-0.08 mol/L when the temperature is 60 ℃ and the pH value is 12.55 and 12.15, and it becomes 0.05-0.08 mol/L when the pH value decreases to 11.75. There is no significant difference in the sulfate concentration threshold of steel corrosion, because the gypsum covers the steel surface and delays the steel corrosion which formed by the reaction of sulfate with Ca(OH)₂ in the simulated pore solution. Therefore, temperature and pH value have not significant effect on the corrosion concentration threshold caused by SO₄^2-. Under the combined action of Cl^- and SO₄^2-, SO₄^2- will repel the Cl^-, and it reacts with Ca²⁺ to form CaSO₄, which covers the surface of steel bar, densifies the passive film, and slows down the corrosion rate of steel bar. When the pH value is 12.55 and 12.15, SO₄^2- reaches 0.03 mol/L and 0.04 mol/L respectively, which can inhibit the corrosion of steel bar caused by Cl^-. However, when the pH value is 11.75, SO₄^2- has not inhibition effect on the corrosion of steel bar caused by Cl^-.

Methods

The electrochemical experimental instrument was Wuhan Koster electrochemical workstation, model CS1350, with a current range of 2 μA-20 A and a constant potential control range of ±10 V. A three-electrode system includes working electrode, counter electrode, and reference electrode, was chosen for electrochemical testing, that is, the steel bar sheet (10 mm in diameter and 0.785 cm² of exposed area) as the working electrode, a platinum sheet electrode (20.0 mm×20.0 mm×0.1 mm) as the counter electrode, and a saturated copper sulfate electrode (CSE) as the reference one. The corrosion potential (E_corr) of the steel bars was tested by the Open Circuit Potential Method (OCP). During the test, the working electrode was immersed in the simulation solution, and the test began after the corrosion potential of the steel bar was stable. Then the polarization curve of the steel bar was tested by linear polarization method (LPR), the changes of corrosion current density (I_corr) and polarization resistance (R_p) of the steel bar were analyzed. The corrosion products of steel bars under different erosion ions were studied by X-ray diffractometer.

Results and discussion

In this paper, rapid corrosion tests of steel bars in concrete simulated pore solutions under the combined effect of different temperatures, erosion ions types and concentrations and pH values were carried out. The critical chloride ion concentration and sulfate concentration thresholds for the steel to start rusting in different temperatures and pH values were clarified. Moreover, the corrosion products generated by steel corrosion under different erosion ions were investigated by XRD.

Conclusions

The results showed that the critical chloride ion concentration of steel corrosion was 0.04-0.06 mol/L in the saturated concrete simulated solution with pH value of 12.55 at 60 ℃. When the pH value reduced to 12.15 and 11.75, the stability of the passivation film decreased at the same time. The critical concentration of chloride ion also reduced to 0.03-0.05 mol/L and 0.02-0.04 mol/L. The corrosion induction period of steel bar becomes longer when the steel bar is eroded by single sulfate. The threshold value of sulfate ion concentration is between 0.06-0.08 mol/L when the temperature is 60 ℃ and the pH value is 12.55 and 12.15, and it becomes 0.05-0.08 mol/L when the pH value decreases to 11.75. There is no significant difference in the sulfate concentration threshold of steel corrosion, because the gypsum covers the steel surface and delays the steel corrosion which formed by the reaction of sulfate with Ca(OH)₂ in the simulated pore solution. Therefore, temperature and pH value have not significant effect on the corrosion concentration threshold caused by SO₄^2-. Under the combined action of Cl^- and SO₄^2-, SO₄^2- can inhibit the corrosion of steel bar caused by Cl^- when the pH value is 12.55 and 12.15, and the corresponding concentration of SO₄^2- is 0.03 mol/L and 0.04 mol/L. However, when pH decreased to 11.75, SO₄^2- had not inhibition effect on steel bar corrosion caused by Cl^-.

Key words

high geothermal environment / corrosion of reinforcement / high temperature / pore solution pH value / chloride and sulfate complex interaction

引用本文

王艳, 吴杰, 张少辉, 牛荻涛. 高地热环境多因素影响混凝土模拟孔溶液中钢筋腐蚀行为. 硅酸盐学报, 2024 , 52 (11) : 3583 -3593 . DOI: 10.14062/j.issn.0454-5648.20230879

Yan WANG, Jie WU, Shaohui ZHANG, Ditao NIU. Corrosion Behavior of Steel Bars in Simulated Pore Solution of Concrete Under High Geothermal Environment[J]. Journal of the Chinese Ceramic Society, 2024 , 52 (11) : 3583 -3593 . DOI: 10.14062/j.issn.0454-5648.20230879

基金

收起

国家优秀青年科学基金(52222806)
陕西省杰出青年科学基金(2022JC-20)
国家自然科学基金(52078413)

参考文献

收起

文献

收起

参考文献引证文献

排序方式：

2024年第52卷第11期

PDF下载

引用本文

BibTeX

文章信息

doi: 10.14062/j.issn.0454-5648.20230879

接收时间：2023-11-17
首发时间：2026-10-22
出版时间：2024-11-20

补充材料

相关文章

文章信息

作者

出版历史

收稿日期：2023-11-17
修回日期：2023-12-09

基金

国家优秀青年科学基金(52222806)

陕西省杰出青年科学基金(2022JC-20)

国家自然科学基金(52078413)

作者信息

^1．西安建筑科技大学材料科学与工程学院，西安 710055

^2．西安建筑科技大学土木工程学院，西安 710055

^3．绿色建筑全国重点实验室，西安建筑科技大学，西安 710055

参考文献

分享链接

https://castjournals.cast.org.cn/joweb/gsyxb/CN/10.14062/j.issn.0454-5648.20230879

分享至

全文二维码

扫描看全文

引用本文

BibTeX

本文的引用情况

2种不同金属材料的力学参数

科 Family	属数 Number of genus	种数 Number of species	占总种数比例 Percentage of total species (%)	属 Genus	种数 Number of species	占总种数比例 Percentage of total species (%)
鹅膏菌科Amanitaceae	2	11	5.26	鹅膏菌属 Amanita	10	4.78
小菇科 Mycenaceae	2	12	5.74	丝盖伞属 Inocybe	5	2.39
多孔菌科 Polyporaceae	8	14	6.70	蜡蘑属 Laccaria	5	2.39
红菇科 Russulaceae	3	23	11.00	小皮伞属 Marasmius	6	2.87
				小菇属 Mycena	11	5.26
				光柄菇属 Pluteus	5	2.39
				红菇属 Russula	17	8.13
				栓菌属 Trametes	5	2.39

关闭全屏

BibTeX
EndNote
RefWorks
TxT