李杰,温小栋,骆忠江,胡立标,冯蕾.钢筋混凝土埋入式牺牲阳极阴极保护试验研究[J].表面技术,2023,52(12):390-398, 418.
LI Jie,WEN Xiao-dong,LUO Zhong-jiang,HU Li-biao,FENG Lei.Experimental Research on Cathodic Protection of Embedded Sacrificial Zinc Anode for Reinforced Concrete[J].Surface Technology,2023,52(12):390-398, 418 |
| 钢筋混凝土埋入式牺牲阳极阴极保护试验研究 |
| Experimental Research on Cathodic Protection of Embedded Sacrificial Zinc Anode for Reinforced Concrete |
| 投稿时间：2022-10-25 修订日期：2023-04-13 |
| DOI：10.16490/j.cnki.issn.1001-3660.2023.12.033 |
| 中文关键词: 钢筋混凝土 阴极保护 牺牲阳极 埋入式 |
| 英文关键词:reinforced concrete cathodic protection sacrificial anode embedded |
| 基金项目:国家自然科学基金(51569035);宁波市科技创新2025重大专项(2020Z056) |
| 作者 | 单位 |
| 李杰 | 宁波工程学院，浙江 宁波 315211 |
| 温小栋 | 宁波工程学院，浙江 宁波 315211 |
| 骆忠江 | 浙江钰烯腐蚀控制股份有限公司，浙江 宁波 315100 |
| 胡立标 | 浙江钰烯腐蚀控制股份有限公司，浙江 宁波 315100 |
| 冯蕾 | 宁波工程学院，浙江 宁波 315211 |
|
| Author | Institution |
| LI Jie | Ningbo University of Technology, Zhejiang Ningbo 315211, China |
| WEN Xiao-dong | Ningbo University of Technology, Zhejiang Ningbo 315211, China |
| LUO Zhong-jiang | Zhejiang Yuxi Corrosion Control Corporation Contact, Zhejiang Ningbo 315100, China |
| HU Li-biao | Zhejiang Yuxi Corrosion Control Corporation Contact, Zhejiang Ningbo 315100, China |
| FENG Lei | Ningbo University of Technology, Zhejiang Ningbo 315211, China |
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| 中文摘要: |
| 目的 提高现有牺牲阳极阴极保护技术的效果，采用活性阳极包覆砂浆，制备一种埋入式牺牲阳极，并研究其应用特性。方法 采用二电极法测试阳极包覆砂浆的电阻率，通过加速试验、SEM-EDS分析锌腐蚀产物的迁移状况，采取自耦合试验测定埋入式牺牲阳极下钢筋的电位等参数;在此基础上，研究埋入式牺牲阳极的特性及其阴极保护范围。结果 活性阳极包覆砂浆的电阻率仅为18.48 Ω.m。闭路电位、瞬间断电电位测试显示钢筋的稳定保护电位为−400~ −440 mV，断电电位为−218 mV，满足NACE标准对衰减电位的最低要求(200 mV)。电流密度结果表明，埋入式阳极可提供的保护电流密度为6.1~7.7 mA/m2，符合EN 12696要求。通过网格法测量的结果显示，在钢筋密度比为0.20，以及高腐蚀环境条件下，埋入式牺牲阳极的最大有效保护距离可达到700 mm。SEM-EDS分析结果表明，锌阳极发生反应，生成了可溶性锌酸盐(ZnO22−)，且会由锌阳极表面向砂浆内部迁移，最终逐渐分散到砂浆孔隙中，可有效解决因锌阳极表面腐蚀产物聚集而影响活性的问题，并消除腐蚀产物体积增大造成的膨胀应力。工程应用结果表明，各测试点钢筋的保护电位均负于−400 mV，满足保护要求。结论 埋入式牺牲阳极对钢筋有较好的保护效果，能够保持电位、电流输出稳定，不会影响阳极的活性，也不会给混凝土结构带来膨胀应力。 |
| 英文摘要: |
| Cathodic protection with sacrificial anode is an economical and effective auxiliary measure for enhancing durability of concrete structures. However, the resistivity of currently available anode available on market is too high to ensure a high protection current and thus it can only achieve an insufficient protection effect. At the same time, the surface of anode is easy to crust which will affect anode's activity, and even cause expansion cracking of the concrete structure layer. For this reason, the work aims to develop a novel embedded sacrificial anode with high-purity zinc anode as the core material, coated with mortar (including cement, special pore agent and active substance) and conductive steel wire. In order to determine the characteristic performance and protection effect of embedded sacrificial anode, the resistivity of such coating mortar was tested by Double Electrode Method. The protective potential, attenuation potential and ampere density of the sacrificial anode embedded rebar were measured by auto-transformer and experiments. The working mechanism of the embedded sacrificial anode was analyzed by accelerated test and SEM-EDS. The resistivity of active mortar was 18.48 Ω.m. The resistivity was low enough to facilitate cathodic protection reaction. During the 30 day curing period, the anode output current rapidly dropped to 0.72 mA, and after 60 days, the current output was stable at 0.40-0.50 mA. An effective basis was provided for the design and application of embedded sacrificial anode in offshore concrete structures. The closed circuit potential and instantaneous off potential tests showed that the protection potential of the rebar was stabled at −400-−440 mV, and the instant off potential was −218 mV, meeting the requirements of NACE standard for the minimum attenuation potential of 200 mV. The protective current density provided by the embedded anode was 6.1- 7.7 mA/m2, meeting the current density requirements in EN12696. The maximum effective protection distance of the developed embedded sacrificial anode could reach 700 mm under the highly corrosive environment when the reinforcement density ratio was 0.20. The effective protection ranges under other different reinforcement density ratios and corrosive environment conditions were also measured and analyzed. SEM-EDS analysis showed that the zinc anode reaction generated zincate (ZnO22−), which would migrate from the zinc anode surface to the interior of the mortar as the reaction proceeded, and eventually gradually dispersed into the pores of the mortar, preventing the lowering of anode activity due to the aggregation of corrosion products on the zinc anode surface, and therefore eliminating the expansion stress caused by the volume increasing of corrosion products. Finally, such design was applied and tested in a real project, i.e. the concrete foundation structure of the cable tower of Rushankou Bridge in Shandong China. The measured protective potential at all test points were all lower than −400 mV, meeting the protection requirements. As a result, it is safe to conclude that the developed embedded sacrificial anode has a good protection effect on rebar as the testing results prove that the protection potential and current output are stable, which will not affect the anode activity or cause expansion stress on the concrete structure. |
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