含气量和掺合料对钢筋锈蚀性能的影响研究
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摘要
混凝土中的钢筋锈蚀引起的混凝土结构过早破坏是导致混凝土耐久性不足的首要原因之一,给世界各国造成了巨大的经济损失。钢筋锈蚀已成为国内外学者们关注的热点问题。在混凝土中引入适量气体可以显著提高混凝土的耐久性,特别是在气候寒冷的北方地区,引气已成为提高混凝土抗冻性的最有效途径,而掺合料作为配制高性能混凝土必不可少的组分之一已被广泛应用,因此,研究掺合料和含气量对混凝土抗钢筋锈蚀性能的影响具有重要意义。
本文以掺合料、含气量、水灰比、等因素作为变量制作了不同种类的含钢筋的混凝土试件。在三种不同加速锈蚀制度下,利用线性极化法测得的电化学参数来比较各种因素对混凝土抗钢筋锈蚀性能的影响,并用氯离子扩散系数和碳化深度分别来评价混凝土的抗渗性和抗碳化性能。试验结果表明,在热干湿交替加速锈蚀(盐水)和外加电流加速锈蚀条件下,混凝土抗钢筋锈蚀性能与抗氯离子渗透性之间存在着密切的关系,混凝土抗氯离子渗透性越好,其抗钢筋锈蚀性能也越强;28d和56d养护龄期时,在这两种加速锈蚀制度下,以30%混掺(矿渣:粉煤灰=1:1)方式制备的混凝土抗钢筋锈蚀性能最好。在淡水热干湿交替加速锈蚀条件下,混凝土抗钢筋锈蚀性能与抗碳化性能规律之间存在着密切的关系,即混凝土抗碳化性能越好,其抗钢筋锈蚀性能也就越优异;56d养护龄期时,在淡水热干湿交替加速锈蚀条件下,矿渣掺量为30%的混凝土抗钢筋锈蚀性能最好,而粉煤灰掺量为30%的抗钢筋锈蚀性能最差。热干湿交替加速锈蚀制度比通电法加速锈蚀能更好地模拟实际环境中混凝土内钢筋的锈蚀。含气量接近4%时,存在一最佳含气量值,使其抗渗性、抗碳化性能和抗钢筋锈蚀性能最好。
Now in the world, the early structure failure of concrete caused by reinforcement corrosion is considerd as the principal factor to induce the deficiency of concrete durability and it has caused huge pecuniary loss to the world. The problem of reinforcement corrosion has been drawing extensive attention of academic circles. To induce proper volume of air by air entraining agents can obviously improve the durability of concrete, especially in the cold north of China, this has become the most effective step to raise frost resistence, while mineral admixtures has been widely used as one of the essential compositons to produce high performance concrete. Therefore, to research the influence of the mineral admixture and air content on the reinforcement corrosion resistence has important significance.
In this paper, we prepare different kinds of concrete by the factors such as mineral admixtures, air content, W/C and so on. Under the three systems to accelerate corrosion process, we compare the impact of the various factors above on the corrosion resistance by the electrochemical parameters attained by the linear polarization method. Besides, we evaluate the impermeability and carbonization resistance by chloride ion diffusion coefficient and carbonization depth differently. The result indicates that, under the conditions of hot alternation of wetting and drying corrosion accerlating (saline) and external current flow corrosion accerlating, the corrosion resistance has close relationship with impermeability of concrete, that is to say, the better the impermeability is, the better the corrosion resistance is; under the two accerlating conditions, concrete prepared by the 30% mineral admixture (Slag: FA =1:1) enjoys the best corrosion resistance among them with 28d and 56d curing age, while under the hot alternation of wetting and drying corrosion accerlating (fresh water), the better carbonization resistance is, the better the corrosion resistance is, the concrete prepared by 30% of salg has the best corrosion resistance with 56d curing age. Compared with external current flow corrosion accerlating, the system of hot alternation of wetting and drying corrosion accerlating can better simulate the corrosion process under the pratical environment. When the air content induced into the concrete arrives at 4% or so, it will have the best impermeability、carbonization resistance and corrosion resistance.
本文以掺合料、含气量、水灰比、等因素作为变量制作了不同种类的含钢筋的混凝土试件。在三种不同加速锈蚀制度下,利用线性极化法测得的电化学参数来比较各种因素对混凝土抗钢筋锈蚀性能的影响,并用氯离子扩散系数和碳化深度分别来评价混凝土的抗渗性和抗碳化性能。试验结果表明,在热干湿交替加速锈蚀(盐水)和外加电流加速锈蚀条件下,混凝土抗钢筋锈蚀性能与抗氯离子渗透性之间存在着密切的关系,混凝土抗氯离子渗透性越好,其抗钢筋锈蚀性能也越强;28d和56d养护龄期时,在这两种加速锈蚀制度下,以30%混掺(矿渣:粉煤灰=1:1)方式制备的混凝土抗钢筋锈蚀性能最好。在淡水热干湿交替加速锈蚀条件下,混凝土抗钢筋锈蚀性能与抗碳化性能规律之间存在着密切的关系,即混凝土抗碳化性能越好,其抗钢筋锈蚀性能也就越优异;56d养护龄期时,在淡水热干湿交替加速锈蚀条件下,矿渣掺量为30%的混凝土抗钢筋锈蚀性能最好,而粉煤灰掺量为30%的抗钢筋锈蚀性能最差。热干湿交替加速锈蚀制度比通电法加速锈蚀能更好地模拟实际环境中混凝土内钢筋的锈蚀。含气量接近4%时,存在一最佳含气量值,使其抗渗性、抗碳化性能和抗钢筋锈蚀性能最好。
Now in the world, the early structure failure of concrete caused by reinforcement corrosion is considerd as the principal factor to induce the deficiency of concrete durability and it has caused huge pecuniary loss to the world. The problem of reinforcement corrosion has been drawing extensive attention of academic circles. To induce proper volume of air by air entraining agents can obviously improve the durability of concrete, especially in the cold north of China, this has become the most effective step to raise frost resistence, while mineral admixtures has been widely used as one of the essential compositons to produce high performance concrete. Therefore, to research the influence of the mineral admixture and air content on the reinforcement corrosion resistence has important significance.
In this paper, we prepare different kinds of concrete by the factors such as mineral admixtures, air content, W/C and so on. Under the three systems to accelerate corrosion process, we compare the impact of the various factors above on the corrosion resistance by the electrochemical parameters attained by the linear polarization method. Besides, we evaluate the impermeability and carbonization resistance by chloride ion diffusion coefficient and carbonization depth differently. The result indicates that, under the conditions of hot alternation of wetting and drying corrosion accerlating (saline) and external current flow corrosion accerlating, the corrosion resistance has close relationship with impermeability of concrete, that is to say, the better the impermeability is, the better the corrosion resistance is; under the two accerlating conditions, concrete prepared by the 30% mineral admixture (Slag: FA =1:1) enjoys the best corrosion resistance among them with 28d and 56d curing age, while under the hot alternation of wetting and drying corrosion accerlating (fresh water), the better carbonization resistance is, the better the corrosion resistance is, the concrete prepared by 30% of salg has the best corrosion resistance with 56d curing age. Compared with external current flow corrosion accerlating, the system of hot alternation of wetting and drying corrosion accerlating can better simulate the corrosion process under the pratical environment. When the air content induced into the concrete arrives at 4% or so, it will have the best impermeability、carbonization resistance and corrosion resistance.
引文
1 P. K. Mehta. Concrete durability-fifty years progress. Process of 2nd International Conference On Concrete Durability. 1991: 1~31
2洪定海.混凝土中钢筋的腐蚀与保护.北京:中国铁道出版社. 1998, 9: 154~167
3 R. K. Dhir, M. R .Jones. Rapid estimation of chloride diffusion concrete. Magazine of concrete Research. 1990(152): 177~185
4 Suad Al-Bahar. Investigation of corrosion damage in a reinforced concrete structure in Kuwait. ACI Materials Journal, 1998(3): 226~231
5邸小坛,高小旺,徐有邻.我国混凝土结构的耐久性与安全问题,工程科技论坛—土建结构工程的安全性与耐久性.北京: 2005, 11: 260~265
6李田,刘西拉.混凝土耐久性分析与设计.北京:科学出版社. 1999: 15~20
7金伟梁,赵羽习.混凝土结构耐久性.科学出版社. 2004: 70~76
8张伟平.混凝土结构钢筋锈蚀损伤识别及其耐久性[博士学位论文].上海同济大学. 1999: 13~17
9 M. A. Lacasse, D. J. Vanier. Service Life and Durability Issues. 7th International Conference on the Durability of Building Materials and Components. Stockholm, 2006: 345~351
10 Nobuaki Otsuki, Shin-ichi Miyazato. Influences of Bending Crack and Water-Cement Ration on Chloride-induced Corrosion of Main Reinforcing Bars and Stirrups. ACI Materials Journal/July-August 2005: 23~27
11 K.R. Gowers and S.G. Millard. Measurement of Concrete Resistivity for Assessment of Corrosion Sevierity of Steel Using Wenner Technique. ACI Materials Journal, September-October, 2004: 139~141
12奥地利H.索默.高性能混凝土的耐久性.北京:科学出版社, 1998, 3:114~176
13森永繁.铁筋の腐食速度に基ついた铁筋コンクリ-ト建筑物の寿命预测に关する研究.清水建设研究报告,日本,1988: 213~217
14武若耕司.コンクリ-トの非破坏检查技术——钢材腐食,コンクリ-ト工学, 1995, 33(3): 123~129
15姬永升,张习美.混凝土中钢筋锈蚀过程的研究现状及评述.建筑材料学报. 2004, 5(1): 22~25
16王军强,沈德建,曹小玉.水工混凝土结构钢筋锈蚀机理及其检测评定.江苏煤炭. 2005, (4): 51~53
17 Sagoe K K, Crentsil, Glasser F R. Electrochemical Characteristics of Reinforced Concrete Corrosion as Determined by Impedance Spectroscopy. Br. Corros. J, 2004, 27(2): 36~40
18 Rachel J. Detwiler, Knut O. Kjellsen. Resistance to Chloride Intrusion of concrete Cured at different Temperatures. ACI Materials Journal, January-February 1991: 456~473
19 K. Tuutti. Corrosion of steel in concrete. CBI. Research Report 4: 82. Stockholm. Sweden. 2005: 56~58
20 Grimalde, G.Factors. Influencing Electrode Potential of Steel in Concrete. Br.Corros. J. 1986, 21(1): 52~57
21罗刚.氯离子侵蚀环境下钢筋混凝土构件的耐久寿命预测[硕士学位论文],华侨大学, 2004: 7~8
22 Zhang Minhong, GjorvOE. Permeability of High-Strength Lightweight Concrete. ACI Materials Journal, 2001, (88): 463~469
23刘西拉,苗澎柯.混凝土结构中的钢筋腐蚀及其耐久性计算.土木工程学报. 1990(4): 213~229
24肖从真.混凝土中钢筋腐蚀的机理研究及数论模拟方法.北京:清华大学,1995: 37~42
25牛荻涛,王庆霖,王林科.锈蚀开裂前混凝土中钢筋锈蚀量的预测模型.工业建筑. 1996(4): 212~219
26邸小坛,周燕.大气环境下钢筋锈蚀规律的研究.第四届全国混凝土耐久性学术交流会论文集,苏州, 1996: 64~78
27 L. Hachani, etal. Characterization of Steel/Concrete Interface by Electro-chemical Impedance Spectroscopy. Br. Corrosion. J. 2004: 29
28 P. S. Mangat, B. T. Molloy. Prediction of long term chloride concentration in concrete. Materials and Structures. 2004, (27): 338~34
29袁广林.高性能混凝土中氯离子的渗透及结构的耐久性估计.工业建筑. 1997, 27(5): 11~13.
30孟振全.表面渗透性对混凝土耐久性的影响.工业建筑. 1994, 24(5):46~49.
31李淑进,吴科如,赵铁军.混凝土渗透性与碳化作用下钢筋锈蚀量的关系建筑材料学报. 2004, 7(1): 89~93
32赵铁军.高性能混凝土的渗透性研究.北京:清华大学土木水利学院, 1997:231~237
33杨钱荣,朱蓓蓉.掺粉煤灰和引气剂混凝土氯离子渗透性能研究.低温建筑技术. 2005, (5): 2~3
34谢友均,刘宝举,刘伟.矿物掺合料对高性能混凝土抗氯离子渗透性能的影响.铁道科学与工程学报. 2004, (1): 48~49
35陈剑雄,石宁,张旭.高掺量复合矿物掺合料自密实混凝土耐久性研究.混凝土. 2005, (1): 24~25
36卫蕊艳.矿渣微粉对混凝土耐久性的影响.新世纪水泥导报. 2005, (2): 27~28
37罗碧丹,赵文利,范志宏.矿物掺合料对混凝土性能影响的研究.华南溢工. 2007, (4): 17~18
38王培铭,朱艳芳,计亦奇,沈中林.复掺粉煤灰和矿渣粉大流动度混凝土的抗碳化性能.粉煤灰. 2002, (7): 9~11
39杨钱荣,杨全兵.掺粉煤灰和引气剂混凝土的碳化性能研究.粉煤灰综合利用. 2006, (1): 4~5
40朱艳芳,王培铭.大掺量粉煤灰混凝土的抗碳化性能研究.建筑材料学报. 1999, (4): 321~322
41 Tang Luping and Nilsson. Rapid determination of the chloride diffusivity in concrete by applying an electric field. ACI Materials Journal. 2004: 49~53
42张保渠,李冠华.混凝土内钢筋腐蚀速度的研究现状与分析.徐州建筑职业技术学院学报. 2005, 9: 28~31
43许丽萍,吴学礼.含Cl-环境下混凝土使用寿命预测.上海建材学院学报,1994, 7(4): 322~329
2洪定海.混凝土中钢筋的腐蚀与保护.北京:中国铁道出版社. 1998, 9: 154~167
3 R. K. Dhir, M. R .Jones. Rapid estimation of chloride diffusion concrete. Magazine of concrete Research. 1990(152): 177~185
4 Suad Al-Bahar. Investigation of corrosion damage in a reinforced concrete structure in Kuwait. ACI Materials Journal, 1998(3): 226~231
5邸小坛,高小旺,徐有邻.我国混凝土结构的耐久性与安全问题,工程科技论坛—土建结构工程的安全性与耐久性.北京: 2005, 11: 260~265
6李田,刘西拉.混凝土耐久性分析与设计.北京:科学出版社. 1999: 15~20
7金伟梁,赵羽习.混凝土结构耐久性.科学出版社. 2004: 70~76
8张伟平.混凝土结构钢筋锈蚀损伤识别及其耐久性[博士学位论文].上海同济大学. 1999: 13~17
9 M. A. Lacasse, D. J. Vanier. Service Life and Durability Issues. 7th International Conference on the Durability of Building Materials and Components. Stockholm, 2006: 345~351
10 Nobuaki Otsuki, Shin-ichi Miyazato. Influences of Bending Crack and Water-Cement Ration on Chloride-induced Corrosion of Main Reinforcing Bars and Stirrups. ACI Materials Journal/July-August 2005: 23~27
11 K.R. Gowers and S.G. Millard. Measurement of Concrete Resistivity for Assessment of Corrosion Sevierity of Steel Using Wenner Technique. ACI Materials Journal, September-October, 2004: 139~141
12奥地利H.索默.高性能混凝土的耐久性.北京:科学出版社, 1998, 3:114~176
13森永繁.铁筋の腐食速度に基ついた铁筋コンクリ-ト建筑物の寿命预测に关する研究.清水建设研究报告,日本,1988: 213~217
14武若耕司.コンクリ-トの非破坏检查技术——钢材腐食,コンクリ-ト工学, 1995, 33(3): 123~129
15姬永升,张习美.混凝土中钢筋锈蚀过程的研究现状及评述.建筑材料学报. 2004, 5(1): 22~25
16王军强,沈德建,曹小玉.水工混凝土结构钢筋锈蚀机理及其检测评定.江苏煤炭. 2005, (4): 51~53
17 Sagoe K K, Crentsil, Glasser F R. Electrochemical Characteristics of Reinforced Concrete Corrosion as Determined by Impedance Spectroscopy. Br. Corros. J, 2004, 27(2): 36~40
18 Rachel J. Detwiler, Knut O. Kjellsen. Resistance to Chloride Intrusion of concrete Cured at different Temperatures. ACI Materials Journal, January-February 1991: 456~473
19 K. Tuutti. Corrosion of steel in concrete. CBI. Research Report 4: 82. Stockholm. Sweden. 2005: 56~58
20 Grimalde, G.Factors. Influencing Electrode Potential of Steel in Concrete. Br.Corros. J. 1986, 21(1): 52~57
21罗刚.氯离子侵蚀环境下钢筋混凝土构件的耐久寿命预测[硕士学位论文],华侨大学, 2004: 7~8
22 Zhang Minhong, GjorvOE. Permeability of High-Strength Lightweight Concrete. ACI Materials Journal, 2001, (88): 463~469
23刘西拉,苗澎柯.混凝土结构中的钢筋腐蚀及其耐久性计算.土木工程学报. 1990(4): 213~229
24肖从真.混凝土中钢筋腐蚀的机理研究及数论模拟方法.北京:清华大学,1995: 37~42
25牛荻涛,王庆霖,王林科.锈蚀开裂前混凝土中钢筋锈蚀量的预测模型.工业建筑. 1996(4): 212~219
26邸小坛,周燕.大气环境下钢筋锈蚀规律的研究.第四届全国混凝土耐久性学术交流会论文集,苏州, 1996: 64~78
27 L. Hachani, etal. Characterization of Steel/Concrete Interface by Electro-chemical Impedance Spectroscopy. Br. Corrosion. J. 2004: 29
28 P. S. Mangat, B. T. Molloy. Prediction of long term chloride concentration in concrete. Materials and Structures. 2004, (27): 338~34
29袁广林.高性能混凝土中氯离子的渗透及结构的耐久性估计.工业建筑. 1997, 27(5): 11~13.
30孟振全.表面渗透性对混凝土耐久性的影响.工业建筑. 1994, 24(5):46~49.
31李淑进,吴科如,赵铁军.混凝土渗透性与碳化作用下钢筋锈蚀量的关系建筑材料学报. 2004, 7(1): 89~93
32赵铁军.高性能混凝土的渗透性研究.北京:清华大学土木水利学院, 1997:231~237
33杨钱荣,朱蓓蓉.掺粉煤灰和引气剂混凝土氯离子渗透性能研究.低温建筑技术. 2005, (5): 2~3
34谢友均,刘宝举,刘伟.矿物掺合料对高性能混凝土抗氯离子渗透性能的影响.铁道科学与工程学报. 2004, (1): 48~49
35陈剑雄,石宁,张旭.高掺量复合矿物掺合料自密实混凝土耐久性研究.混凝土. 2005, (1): 24~25
36卫蕊艳.矿渣微粉对混凝土耐久性的影响.新世纪水泥导报. 2005, (2): 27~28
37罗碧丹,赵文利,范志宏.矿物掺合料对混凝土性能影响的研究.华南溢工. 2007, (4): 17~18
38王培铭,朱艳芳,计亦奇,沈中林.复掺粉煤灰和矿渣粉大流动度混凝土的抗碳化性能.粉煤灰. 2002, (7): 9~11
39杨钱荣,杨全兵.掺粉煤灰和引气剂混凝土的碳化性能研究.粉煤灰综合利用. 2006, (1): 4~5
40朱艳芳,王培铭.大掺量粉煤灰混凝土的抗碳化性能研究.建筑材料学报. 1999, (4): 321~322
41 Tang Luping and Nilsson. Rapid determination of the chloride diffusivity in concrete by applying an electric field. ACI Materials Journal. 2004: 49~53
42张保渠,李冠华.混凝土内钢筋腐蚀速度的研究现状与分析.徐州建筑职业技术学院学报. 2005, 9: 28~31
43许丽萍,吴学礼.含Cl-环境下混凝土使用寿命预测.上海建材学院学报,1994, 7(4): 322~329