QU Feng,HOU Hailong,HU Song,et al.Study on Electrochemical Chloride Extraction effect of Reinforced Concrete after Freeze‑thaw Cycle[J].Journal of Disaster Prevention and Mitigation Engineering,2022,42(02):347-353.
QU Feng,HOU Hailong,HU Song,et al.Study on Electrochemical Chloride Extraction effect of Reinforced Concrete after Freeze‑thaw Cycle[J].Journal of Disaster Prevention and Mitigation Engineering,2022,42(02):347-353. DOI: 10.13409/j.cnki.jdpme.20210121001.
Study on Electrochemical Chloride Extraction effect of Reinforced Concrete after Freeze‑thaw Cycle
In order to explore the distribution of residual chloride ions in reinforced concrete structures after electrochemical chlorine removal in the salt-frozen environment, a rapid freeze-thaw test was designed and electrochemical chloride extraction tests of reinforced concrete after freeze-thaw cycles were carried out. The influence of freeze-thaw cycles, chlorination time and fly ash content on the electrochemical chloride extraction of the reinforced concrete was studied. Studies showed that the electrochemical chloride extraction efficiency of fly ash concrete can be affected by the combined impact of the freeze-thaw action and secondary hydration of fly ash. The deterioration of concrete performance caused by freeze-thaw cycle can lead to the convex distribution of residual chloride ions in concrete after electrochemical chloride extraction. After electrochemical chlorine removal, the residual chloride ions in concrete present a convex distribution trend and gathered in the depth of 15-25 mm from the concrete surface. And the content of residual chloride ions near the reinforcement bar is the lowest. The results show that the freeze-thaw action leads to the increase of average dechlorination efficiency of concrete. Compared with the specimens without freeze-thaw attacking, the average dechlorination efficiency of concrete after 100 freeze-thaw cycles increases by about 12.5%. With the electrochemical chlorine removal time increasing, the average chlorine removal efficiency increases, and the decrease of residual chlorine ions content in concrete is positively correlated with the total amount of external migration. With the fly ash content increasing, the dechlorination efficiency of concrete increases. The 28-day average dechlorination efficiency with fly ash content of 10%, 20% and 30% can reach 51.2%, 54.5% and 59.9%, respectively.
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Song Y P , Song L Y , Zhao G F . Factors affecting corrosion and approaches for improving durability of ocean reinforced concrete structures [J]. Ocean Engineering , 2004 , 31 ( 5-6 ): 789 - 799 .
Sun C , Li H X , Zhang S Q , et al . Review of research on corrosion of reinforced concrete [J]. Materials Review , 2000 , 14 ( 5 ): 27 - 28 . (in Chinese) .
Nguyen H Y T , Pansu K W , Sancharoen P . The effects of electro-chemical chloride extraction on the migration of ions and the corrosion state of embedded steel in reinforced concrete [J]. KSCE Journal of Civil Engineering , 2018 , 22 ( 8 ): 2942 - 2950 .
Shan H Y , Wang Z Y , Xu J X , et al . Influences of fly ash, slag and silica fume on electrochemical chloride removal treatment with simultaneous migration of silicate ion [J]. International Journal of Electrochemical Science , 2018 , 13 ( 6 ): 1120 - 1130 .
Chang C C , Yeih W , Chang J J , et al . Effects of stirrups on electrochemical chloride removal efficiency [J]. Constru- ction and Building Materials , 2014 , 68 ( 10 ): 692 - 700 .
Li S L , Fan W G , Cai W C , et al . Laboratory tests of electrochemical removal of chloride for anti-corrosion [J]. Hydro-Science and Engineering , 2001 ( 3 ): 35 - 40 . (in Chinese)
Jiang W Q , Liu Q F . Chloride transport in concrete subjected to freeze-thaw cycles—A short review [J]. Journal of the Chinese Ceramic Society , 2020 , 48 ( 2 ): 258 - 272 . (in Chinese)
Qiu J S , Xing M , Yang Z L , et al . Pore structure characteristics of polypropylene fiber coal Gangue concrete under freeze-thaw [J]. China Concrete and Cement Products , 2020 ,( 6 ): 41 - 44,48 . (in Chinese)
Jiang L , Niu D T . Study on damage failure criterion of concrete under sulfate attack and freeze-thaw environm- ent [J]. Journal of Disaster Prevention and Mitigation Engineering , 2017 , 37 ( 1 ): 148 - 153 . (in Chinese)
Sun W B , Gao X J , Yang Y Z , et al . Microstructure of concrete after electrochemical chloride extraction treatment [J]. Journal of Harbin Engineering University , 2009 , 30 ( 10 ): 1108 - 1112 . (in Chinese)
Hu J Y , Li S , Lu Y Y , et al . Efficiency of electrochemical extraction of chlorides in fly ash concrete using carbon fibre mesh anode [J]. Construction and Building Materials , 2020 , 249 ( 7 ): 1 - 10 .
Gao X J , Zheng X M , Yang Y Z . Influence of electrochemical parameters on chloride extraction efficiency [J]. Journal of Shenyang University of Technology , 2010 , 32 ( 5 ): 579 - 584 . (in Chinese)
Zhang W W , Mao J H , Sun Y , et al . Experimental research on chloride migration featureduring electrochemical chloride extraction under different electric field direction [J]. Building Science , 2018 , 34 ( 1 ): 38 - 43 . (in Chinese)
Zhu P , Wang X X , Wei J X , et al . Model and numerical analysis of ions migration in concrete during the process of electrochemical chloride extraction [J]. Journal of Wuhan University of Technology , 2011 , 33 ( 5 ): 41 - 47 . (in Chinese)
Zheng L , Wei J X , Yu Q J , et al . Research of the chloride ion migration in concrete during electrochemical chloride extraction [J]. Journal of Wuhan University of Technology , 2011 , 33 ( 2 ): 42 - 45 . (in Chinese)
Qu F , Sun H R , Lei Z H , et al . Effect of several processing factors on electrochemical dechlorination efficiency of reinforced concrete [J]. Corrosion Science and Protection Technology , 2019 , 31 ( 5 ): 515 - 520 . (in Chinese)
Liu J , Liu J Y , Huang Z Y , et al . Effect of fly ash as cement replacement on chloride diffusion, chloride binding capacity, and micro-properties of concrete in a water soaking environment [J]. Applied Sciences , 2020 , 10 ( 18 ): 1 - 16 .
Geng Jian , DaveEasterbrook , Li L Y , et al . The stability of bound chlorides in cement paste with sulfate attack [J]. Cement and Concrete Research , 2015 , 68 ( 2 ): 211 - 222 .
Ipavec A , Tomaž V U K , Gabrovšek , et al . Chloride binding into hydrated blended cements: The influence of limestone and alkalinity [J]. Cement and Concrete Research . 2013 , 48 ( 6 ): 74 - 85 .
Lei Z H . Study on effect of electrochemical chloride extraction and frost resistance after extraction of reinforced concrete components [D]. Xiangtan : Hunan University of Science and Technology , 2018 . (in Chinese)