氯盐侵蚀下铜矿渣混凝土高温后内部钢筋锈蚀规律

陈奇; 公伟; 苗吉军

doi:10.13801/j.cnki.fhclxb.20210622.006

氯盐侵蚀下铜矿渣混凝土高温后内部钢筋锈蚀规律

doi: 10.13801/j.cnki.fhclxb.20210622.006

青岛理工大学　土木工程学院，青岛 266033

基金项目: 山东省自然科学基金项目(ZR2017MEE029)；山东省“双一流”建设工程-土木

详细信息

通讯作者:
公伟，博士，讲师，研究方向为混凝土结构抗火及耐久性　 E-mail：weigong890413@qq.com

中图分类号: TU375
计量
- 文章访问数: 850
- HTML全文浏览量: 534
- PDF下载量: 22
- 被引次数: 0
出版历程
- 收稿日期: 2021-05-26
- 修回日期: 2021-06-13
- 录用日期: 2021-06-16
- 网络出版日期: 2021-06-22
- 刊出日期: 2022-06-01

Corrosion extents of steel bar in copper slag concrete after exposure to high temperature under chloride attack

School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China

摘要

摘要: 为探究高温及铜矿渣细骨料对混凝土中钢筋锈蚀模式的影响规律，对不同铜矿渣置换率的混凝土试件进行高温试验，然后采用干湿循环浸泡法对试件进行人工加速氯离子侵蚀试验，并利用电化学方法测量自然电位值以监测混凝土内部钢筋的锈蚀情况，最后测量混凝土内部氯离子含量及钢筋锈蚀率。结果表明：自然电位法可以较好地反映试件内部钢筋的实际锈蚀情况；高温破坏了混凝土抗氯离子侵蚀性能，从而导致混凝土试件中的钢筋锈蚀程度随经历温度的升高而增大；此外，高温下铜矿渣自身较大的膨胀变形及冷却后与水泥净浆间不协调收缩的综合作用进一步破坏了混凝土微结构，使钢筋锈蚀率随着铜矿渣置换率的提高而增大；最后建立了氯盐侵蚀下铜矿渣混凝土高温后内部钢筋锈蚀深度拟合公式。
- 铜矿渣混凝土 /
- 高温 /
- 氯盐侵蚀 /
- 钢筋锈蚀 /
- 自然电位
Abstract: In order to investigate the influence of high temperature and copper slag fine aggregate on corrosion mode of steel bar in concrete, high temperature test was carried out on concrete specimens with different copper slag replacing ratios, then the artificial accelerated chloride ion corrosion test was conducted on the specimens using dry-wet cycling immersion method, and the corrosion state of steel bars embedded in concrete was monitored by measuring the half-cell potential value using electrochemical method, the chloride ion content in concrete and corrosion rate of steel bar were also measured at last. The results show that the half-cell potential method well reflects the actual corrosion situation of steel bar in specimen. High temperature destroys the chloride ion penetration resistance performance of concrete, thus causing the corrosion degree of steel bar in concrete specimen increases with the increase of heating temperature. In addition, the combined effect of inherent larger expansion deformation of copper slag at high temperature and uncoordinated shrinkage between copper slag and cement paste after cooling furtherly destroys the microstructure of concrete, thus causing the corrosion rate of steel bar increases with the increase of copper slag replacing ratio. A fitting formula for corrosion depth of steel bar in copper slag concrete after exposure to high temperature under chloride attack was established at last.
- copper slag concrete /
- high temperature /
- chloride attack /
- steel bar corrosion /
- half-cell potential

HTML全文

图 1 高温试验电热炉

Figure 1. Electric furnace for high temperature test

下载: 全尺寸图片幻灯片

图 2 试件涂刷环氧树脂

Figure 2. Specimens coated with epoxy resin

下载: 全尺寸图片幻灯片

图 3 自然电位法监测钢筋锈蚀状态

Figure 3. Monitoring steel bar corrosion state by half-cell potential method

下载: 全尺寸图片幻灯片

图 4 高温后铜矿渣混凝土试件

Figure 4. Copper slag concrete specimens after exposure to high temperatures

下载: 全尺寸图片幻灯片

图 5 不同铜矿渣置换率铜矿渣混凝土试件自然电位变化曲线

Figure 5. Half-cell potential variation curves of copper slag concrete specimens with different copper slag replacing ratios

下载: 全尺寸图片幻灯片

图 6 经历不同温度铜矿渣混凝土试件自然电位变化曲线

Figure 6. Half-cell potential variation curves of copper slag concrete specimens with different heating temperatures

下载: 全尺寸图片幻灯片

图 7 经历不同温度的20%Cu/NC试件钢筋

Figure 7. Steel bars in 20%Cu/NC specimens with different heating temperatures

下载: 全尺寸图片幻灯片

图 8 100℃后不同铜矿渣置换率铜矿渣混凝土试件钢筋

Figure 8. Steel bars in copper slag concrete specimens with different copper slag replacing ratios after 100℃ heating

下载: 全尺寸图片幻灯片

图 9 钢筋锈蚀率变化曲线

Figure 9. Variation curves of steel bar corrosion rate

下载: 全尺寸图片幻灯片

图 10 测量混凝土中氯离子含量

Figure 10. Measurement of chloride ion content in concrete

下载: 全尺寸图片幻灯片

图 11 钢筋处混凝土中自由氯离子含量

Figure 11. Free chloride ion content in concrete near steel bar

下载: 全尺寸图片幻灯片

图 12 钢筋锈蚀深度与自由氯离子含量关系曲线

Figure 12. Steel bar corrosion depth and free chloride ion content relationship curves

下载: 全尺寸图片幻灯片

表 1 铜矿渣混凝土配合比

Table 1. Mix proportions of copper slag concrete

Sample	Water to binder ratio/%	Replacing ratio/wt%	Mix proportions/(kg·m⁻³)
Sample	Water to binder ratio/%	Replacing ratio/wt%	Water	Cement	Fly ash	Gravel	Sand	Copper slag	Superplasticizer
NC	40	0	200	300	200	860	845	0	9.0
20%Cu/NC		20	200	300	200	860	676	169	5.0
40%Cu/NC		40	200	300	200	860	507	338	4.0

下载: 导出CSV

表 2 铜矿渣的化学成分

Table 2. Chemical composition of copper slag

Chemical composition	Content/wt%
SiO₂	33-35
Fe₂O₃	42-50
CaO	3-10
MgO	1-5
Al₂O₃	3-7
Cu	0.5-2
S	0-2

下载: 导出CSV

表 3 铜矿渣混凝土试件分组情况

Table 3. Test group of copper slag concrete specimens

Name	Specimen	Copper slag/wt%	Heating temperature/℃	Corrosion time/day	Number
NC	NC-20℃-60d	0	20	60	3
	NC-100℃-60d	0	100	60	3
	NC-200℃-60d	0	200	60	3
	NC-300℃-60d	0	300	60	3
20%Cu/NC	20%Cu/NC-20℃-60d	20	20	60	3
	20%Cu/NC-100℃-60d	20	100	60	3
	20%Cu/NC-200℃-60d	20	200	60	3
	20%Cu/NC-300℃-60d	20	300	60	3
40%Cu/NC	40%Cu/NC-20℃-60d	40	20	60	3
	40%Cu/NC-100℃-60d	40	100	60	3
	40%Cu/NC-200℃-60d	40	200	60	3
	40%Cu/NC-300℃-60d	40	300	60	3

下载: 导出CSV

表 4 高温后铜矿渣混凝土试件外观特征

Table 4. Appearance characteristics of copper slag concrete specimens after exposure to high temperature

Heating temperature/℃	Appearance characteristics of specimens
20	Cement-grey, no cracks, dense surface
100	Cement-grey, no cracks, neat edge
200	Mud-grey, no cracks
300	Dark red, micro-cracks

下载: 导出CSV

表 5 钢筋锈蚀情况判断标准

Table 5. Criteria for judging corrosion state of steel bar

Steel bar corrosion state	Half-cell potential/mV
Uncorroded (10% risk of corrosion)	>−90
Uncertain (50% risk of corrosion)	−240-−90
Corroded (90% risk of corrosion)	< −240

下载: 导出CSV

表 6 高温后铜矿渣混凝土试件中钢筋锈蚀情况

Table 6. Corrosion state of steel bar in copper slag concrete specimens after exposure to high temperature

Specimen	Copper slag/wt%	Heating temperature/℃	Corrosion rate/%	d/mm	d_ρ/mm	δ/mm
NC-20℃-60d	0	20	1.304	13.280	13.193	0.0434
NC-100℃-60d	0	100	1.432	13.300	13.204	0.0478
NC-200℃-60d	0	200	1.569	13.310	13.205	0.0524
NC-300℃-60d	0	300	2.088	13.280	13.141	0.0697
20%Cu/NC-20℃-60d	20	20	1.378	13.230	13.139	0.0457
20%Cu/NC-100℃-60d	20	100	1.576	13.210	13.106	0.0522
20%Cu/NC-200℃-60d	20	200	1.775	13.290	13.172	0.0592
20%Cu/NC-300℃-60d	20	300	2.312	13.380	13.224	0.0778
40%Cu/NC-20℃-60d	40	20	1.439	13.320	13.224	0.0481
40%Cu/NC-100℃-60d	40	100	1.674	13.360	13.248	0.0562
40%Cu/NC-200℃-60d	40	200	1.862	13.330	13.205	0.0623
40%Cu/NC-300℃-60d	40	300	2.505	13.330	13.162	0.0840
Notes: d—Diameter of steel bar before corrosion; d_ρ—Diameter of steel bar after corrosion; δ—Average corrosion depth of steel bar.

下载: 导出CSV

参考文献(27)

[1]	智研咨询集团. 2019—2025年中国铜冶炼行业市场深度评估及未来发展趋势研究报告[R]. 北京: 2019. Zhiyan Consulting Group. Research report on market depth assessment and future development trend of China copper smelting industry from 2019 to 2025[R]. Beijing: 2019(in Chinese).
[2]	SONG J, FENG S, XIONG R, et al. Mechanical properties, pozzolanic activity and volume stability of copper slag-filled cementitious materials[J]. Materials Science,2019,26(2):218-224. doi: 10.5755/j01.ms.26.2.21447
[3]	CHITHRA S, SENTHIL KUMAR S R R, CHINNARAJU K. The effect of colloidal nano-silica on workability, mechanical and durability properties of high performance concrete with copper slag as partial fine aggregate[J]. Construction and Building Materials,2016,113:794-804. doi: 10.1016/j.conbuildmat.2016.03.119
[4]	朱街禄, 宋军伟, 王露, 等. 铜矿渣在水泥混凝土应用的研究进展[J]. 硅酸盐通报, 2017, 36(11):3676-3682. ZHU Jielu, SONG Junwei, WANG Lu, et al. Research progress on copper slag in cement and concrete[J]. Bulletin of the Chinese Ceramic Society,2017,36(11):3676-3682(in Chinese).
[5]	LYE C Q, KOH S K, MANGABHAI R, et al. Use of copper slag and washed copper slag as sand in concrete: A state-of-the-art review[J]. Magazine of Concrete Research,2015,67(12):665-679. doi: 10.1680/macr.14.00214
[6]	史公初, 廖亚龙, 张宇, 等. 铜冶炼渣制备建筑材料及功能材料的研究进展[J]. 材料导报, 2020, 34(13):13044-13049. doi: 10.11896/cldb.19040073 SHI Gongchu, LIAO Yalong, ZHANG Yu, et al. Research progress on preparation of building materials and functional materials with copper metallurgical slag[J]. Materials Review,2020,34(13):13044-13049(in Chinese). doi: 10.11896/cldb.19040073
[7]	AFSHOON I, SHARIFI Y. Utilization of micro copper slag in SCC subjected to high temperature[J]. Journal of Building Engineering,2020,29:101128. doi: 10.1016/j.jobe.2019.101128
[8]	杜海云, 郭荣鑫, 马倩敏, 等. 铜渣胶凝材料高温力学性能的实验研究[J]. 硅酸盐通报, 2016, 35 (10):3258-3263. DU Haiyun, GUO Rongxin, MA Qianmin, et al. Mechanical properties of cementitious materials containing copper slag at high temperatures[J]. Bulletin of the Chinese Ceramic Society,2016,35 (10):3258-3263(in Chinese).
[9]	PREM P R, VERMA M, AMBILY P S. Sustainable cleaner production of concrete with high volume copper slag[J]. Journal of Cleaner Production,2018,193:43-58. doi: 10.1016/j.jclepro.2018.04.245
[10]	GUPTA N, SIDDIQUE R. Durability characteristics of self-compacting concrete made with copper slag[J]. Construction and Building Materials,2020,247:118580. doi: 10.1016/j.conbuildmat.2020.118580
[11]	KHARADE A S, KAPADIYA S V, CHAVAN R. An experimental investigation of properties of concrete with partial or full replacement of fine aggregates through copper slag[J]. International Journal of Engineering Research and Technology,2013,2(3):1-10.
[12]	WU W, ZHANG W, MA G. Optimum content of copper slag as a fine aggregate in high strength concrete[J]. Materials and Design,2010,31:2878-2883. doi: 10.1016/j.matdes.2009.12.037
[13]	GONG W, UEDA T. Properties of self-compacting concrete containing copper slag aggregate after heating up to 400℃[J]. Structural Concrete,2018,19(6):1873-1880. doi: 10.1002/suco.201700234
[14]	中华人民共和国住房和城乡建设部. 混凝土结构试验方法标准: GB/T 50152—2012[S]. 北京: 中国建筑工业出版社, 2012. Ministry of Housing and Urban-Rural Development, People’s Republic of China. Standard methods for testing of concrete structures: GB/T 50152—2012[S]. Beijing: China Architecture & Building Press, 2012(in Chinese).
[15]	徐沛. 通电、干湿及盐雾条件下钢筋混凝土锈胀细观试验研究[D]. 深圳: 深圳大学, 2017. XU Pei. Microscopic experimental study on rust expansion of reinforced concrete under impressed current, dry-wet cycling and salt fog conditions[D]. Shenzhen: Shenzhen University, 2017(in Chinese).
[16]	LUNDGREN K, TAHERSHAMSI M, ZANDI K, et al. Tests on anchorage of naturally corroded reinforcement in concrete[J]. Materials and Structures,2015,48:2009-2022. doi: 10.1617/s11527-014-0290-y
[17]	李趁趁, 于爱民, 高丹盈, 等. 侵蚀环境下FRP条带加固锈蚀钢筋混凝土圆柱轴心受压试验[J]. 复合材料学报, 2020, 37(8):2015-2028. LI Chenchen, YU Aimin, GAO Danying, et al. Experimental study on axial compression of corroded reinforced concrete columns strengthened with FRP strips under erosion environment[J]. Acta Materiae Compositae Sinica,2020,37(8):2015-2028(in Chinese).
[18]	柳俊哲, 邢锋, 张振文, 等. 混凝土中钢筋腐蚀的测定与评价方法[J]. 材料导报, 2008(10):80-83. doi: 10.3321/j.issn:1005-023X.2008.10.019 LIU Junzhe, XING Feng, ZHANG Zhenwen, et al. Measuring method and evaluation method of steel corrosion of reinforced concrete[J]. Materials Review,2008(10):80-83(in Chinese). doi: 10.3321/j.issn:1005-023X.2008.10.019
[19]	高新亮, 付贵勤, 朱苗勇, 等. 低合金耐候钢在含氯离子环境中的腐蚀行为[J]. 北京科技大学学报, 2012, 34(11):1282-1287. GAO Xinliang, FU Guiqin, ZHU Miaoyong, et al. Corrosion behavior of low-alloy weathering steel in environment containing chloride ions[J]. Journal of University of Science and Technology Beijing,2012,34(11):1282-1287(in Chinese).
[20]	徐港, 卫军, 王青. 锈蚀钢筋与混凝土粘结性能的梁式试验[J]. 应用基础与工程科学学报, 2009, 17(4):549-557. doi: 10.3969/j.issn.1005-0930.2009.04.007 XU Gang, WEI Jun, WANG Qing. Beam test study on bond behavior of corroded reinforcing bar in concrete[J]. Jour-nal of Basic Science and Engineering,2009,17(4):549-557(in Chinese). doi: 10.3969/j.issn.1005-0930.2009.04.007
[21]	徐港, 费红芳, 刘德富, 等. 混凝土中钢筋锈蚀深度预测模型[J]. 建筑材料学报, 2011, 14(6):844-849. doi: 10.3969/j.issn.1007-9629.2011.06.024 XU Gang, FEI Hongfang, LIU Defu, et al. Prediction model on the rebar corrosion depth in concrete[J]. Journal of Building Materials,2011,14(6):844-849(in Chinese). doi: 10.3969/j.issn.1007-9629.2011.06.024
[22]	中华人民共和国交通运输部. 水运工程混凝土试验检测技术规范: JTS/T 236—2019[S]. 北京: 人民交通出版社, 2019. Ministry of Transport of the People’s Republic of China. Technical specification for concrete testing of port and waterway engineering: JTS/T 236—2019[S]. Beijing: China Communications Press, 2019(in Chinese).
[23]	American Society for Testing and Materials. Standard test method for half-cell potentials of uncoated reinforcing steel in concrete: ASTM C876—91[S]. West Conshohocken: ASTM, 1999.
[24]	韩涛, 靳秀芝, 王慧奇, 等. 高温对水泥石结构和性能的影响及激励分析[J]. 中北大学学报(自然科学版), 2015, 36 (3):378-383. HAN Tao, JIN Xiuzhi, WANG Huiqi, et al. Influence and mechanism analysis of high temperature on the structure and properties of hydrated cement pastes[J]. Journal of North University of China (Natural Science Edition),2015,36 (3):378-383(in Chinese).
[25]	勾密峰, 管学茂, 张海波. 单硫型水化硫铝酸钙对氯离子的固化作用[J]. 建筑材料学报, 2012, 15 (6):863-866. doi: 10.3969/j.issn.1007-9629.2012.06.025 GOU Mifeng, GUAN Xuemao, ZHANG Haibo. Chloride binding in monosulfoaluminate hydrate[J]. Journal of Building Materials,2012,15 (6):863-866(in Chinese). doi: 10.3969/j.issn.1007-9629.2012.06.025
[26]	韩学强, 詹树林, 徐强, 等. 干湿循环作用对混凝土抗氯离子渗透侵蚀性能的影响[J]. 复合材料学报, 2020, 37(1):198-204. HAN Xueqiang, ZHAN Shulin, XU Qiang, et al. Effect of dry-wet cycling on resistance of concrete to chloride ion permeation erosion[J]. Acta Materiae Compositae Sinica,2020,37(1):198-204(in Chinese).
[27]	YANG O, ZHANG B, YAN G, et al. Bond performance between slightly corroded steel bar and concrete after exposure to high temperature[J]. Journal of Structure Engineering,2018,144(11):04018209. doi: 10.1061/(ASCE)ST.1943-541X.0002217