喷射混凝土的硝酸侵蚀:孔溶液H+与NO3-的扩散规律及侵蚀机理

doi:10.11896/cldb.201906015

Abstract
Figure/Table
References
Related Citation (1)

Download:

Full Text ( PDF ) (3809KB)
Export: BibTeX | EndNote (RIS)

Abstract The commonly used single-layer shotcrete linings in long highway tunnels under general atmospheric environment usually suffer nitric acid corrosion, and as consequences, the durability and service lifetime are prone to deterioration. This paper presents the experimental study and the mechanism analysis over the diffusion of hydrogen ions (H⁺) and nitrate ions (NO₃^-) in the pore solution of shotcrete lining experiencing immersion corrosion in nitric acid. The nitric acid (with pH values of 1, 2 and 3) immersion tests upon a series of specimens of ordinary shotcrete, steel-fiber-reinforced shotcrete and cast concrete were conducted. The changes in physical and mechanical properties of the specimens during the entire 180 d immersion process were measured, and the H⁺ and NO₃^- concentration gradients along vertical (depth) direction for the pore solution within the three kinds of concrete specimens were investigated systematically by varying the nitric acid pH value and immersion duration. Moreover, the mineral composition determination and microstructure observation for the corrosion products were also carried out, and the diffusion laws of H⁺ and NO₃^- in the pore solution were analyzed. As was expected, both of the H⁺ and NO₃^- concentrations of pore solution within shotcrete specimens were found to be lower than those for cast concrete specimens, confirming a higher resistance against nitric acid corrosion for shotcrete. The steel fiber addition has inconspicuous effect for the durability improvement of shotcrete under relatively high-concentration nitrate corrosive circumstances, as nearly no difference could be identified for H⁺/NO₃^- concentrations between ordinary shotcrete specimens and steel-fiber-reinforced shotcrete specimens, both of which were immersed in pH≤2 nitric acid. It was concluded according to the corrosion mechanism analysis that the corrosion process of shotcrete in nitric acid includes three steps: reaction of hydration products (with the acid), decomposition of calcium silicate hydrate gel, and corrosion of ettringite and aggregate. Therefore, the pore solution within shotcrete displayed an H⁺ content change tendency of rapid increase (early stage) and subsequent slower increase (late stage), while on the other hand, a NO₃^- content change tendency of always fast increase, as the corrosion getting processed.

Key words： shotcrete nitric acid corrosion pH value of pore solution hydrogen ion (H⁺) concentration nitric ion (NO₃^-) concentration ion diffusion law

Published: 03 April 2019

CLC number:

TU528.44

Fund:This project is financially supported by the National Natural Science Foundation of China (51590914), Natural Science Foundation of Shannxi Province of China (2018JQ5032), Natural Science Foundation of Shannxi Educational Committee (18JK0376), and Presidential Research Foundation of XATU (XAGDXJJ17019).

About author:: Jiabin Wangreceived his Ph.D. degree in Structure Engineering from Xi’an University of Architecture and Technology (XAUAT) in 2017.

	Service
	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	WANG Jiabin
	NIU Ditao

Cite this article:

WANG Jiabin,NIU Ditao. Nitric Acid Immersion Corrosion of Shotcrete Lining: Diffusion Law of Hydrogen Ions (H⁺) and Nitrite Ions (NO₃^-), and the Corrosion Mechanism[J]. Materials Reports, 2019, 33(6): 991-999.

URL:

http://www.mater-rep.com/EN/10.11896/cldb.201906015 OR http://www.mater-rep.com/EN/Y2019/V33/I6/991

1 Alum T. Sprayed concrete lined tunnel, New York, Taylor & Francis,2012.
2 Gary B Hemphill. Practical tunnel construction, Hoboken, Jone Wiley & Sons,2013.
3 Christopher K Y L, Lai R, Lee A Y F.Cement and Concrete Research,2005,35,788.
4 Editorial Department of China Journal of Highway and Transport. China Journal of Highway and Transport,2015,28(5),1(in Chinese).
《中国公路学报》编辑部. 中国公路学报,2015,28(5),1.
5 Tomas F, Garshol K F, Tomisawa N. Tunneling and Underground Space Technology,2001,16,295
6 Wang J B, Niu D T. China Civil Engineering Jounrnal,2018,51(2),95(in Chinese).
王家滨, 牛荻涛. 土木工程学报,2018,51(2),95.
7 Wang J, Niu D, Ding S, et al.Construction and Building Materials,2015,78,203.
8 Lei H G, Wu T, Lv J G. Construction Structure,2007,37(S),8(in Chinese).
雷宏刚, 吴涛, 吕建国. 建筑结构,2007,37(S), 8.
9 Glass G K, Buenfeld N R. Cement & Concrete Research,1999,29(10),1681.
10 Yuan H, Dangla P, Chatellier P, et al. Cement & Concrete Research,2015,70(2),29.
11 Yuan H, Dangla P, Chatellier P, et al. Cement & Concrete Research,2013,53(2),267.
12 Fan Y F, Hu Z Q, Zhang Y Z, et al. Construction & Building Materials,2010,24(10),1975.
13 Ying R R, Zhu H H. Journal of Yangzhou University (Natural Science Edition),2011,14(3),70(in Chinese).
尹蓉蓉, 朱合华. 扬州大学学报(自然科学版),2011,14(3),70.
14 Thomas D. Cement and Concrete Composites,2017,83,20.
15 GB50086-2015. Technical code for engineering of ground anchorages and shotcrete support, China Planning Press,China,2015(in Chinese).
GB50086-2015. 岩土锚杆与喷射混凝土支护工程技术规范,中国计划出版社,2015.
16 Wang J B, Niu D T, Song Z P. Construction & Building Materials,2016,123,346.
17 Xu G, Yang Y H, Xu B, et al. Concrete,2017(2),1(in Chinese).
徐港, 杨亚会, 徐兵,等. 混凝土,2017(2),1.
18 Wang J B, Niu D T, Zhang Y L. Materials & Structures,2016,49(4),1469.
19 Yang N R, Yue W H. Handbook of inorganic non-metallic materials maps, Wuhan University of Technology Press, China,2000(in Chinese).
杨南如, 岳文海. 无机非金属材料图谱手册,武汉工业大学出版社,2000.
20 Huang S J, Huang K K, Feng L W, et al. Geochimica,2009,38(5),498(in Chinese).
黄思静, 黄可可, 冯文立,等. 地球化学,2009,38(5),498.