摘要
针对现有埋入式牺牲阳极对既有钢筋混凝土结构适用性差的问题,研发了一种适用于既有钢筋混凝土结构的埋入式牺牲阳极。通过室内模拟试验,研究了埋入式牺牲阳极在受氯盐侵蚀的混凝土模拟孔隙液和混凝土构件中的钢筋电位、电流、电流密度变化情况以及腐蚀产物扩散行为。结果表明,在混凝土模拟孔隙液中,埋入式牺牲阳极能在6 h内完全极化钢筋,服役过程中钢筋电位始终负于-780 mV,且未超过析氢电位;在混凝土构件中,埋入式牺牲阳极能在6 h内使钢筋极化80%,单只阳极稳定输出电流为0.4 mA,电流密度达到12.74 mA/m^(2),随着埋入式牺牲阳极与钢筋被测点距离的增加,钢筋的极化程度降低,保护作用减弱,最大保护距离为80 cm;阳极腐蚀产物具有扩散行为,以白色细颗粒状分布在砂浆孔隙中,可降低腐蚀产物膨胀导致的混凝土涨裂风险。
In order to address the poor applicability of existing embedded sacrificial anodes in existing reinforced concrete structures,a new type of embedded sacrificial anode applicable to existing reinforced concrete structures was developed.Indoor simulation tests were conducted to investigate the changes in steel reinforcement potential,current,and current density,as well as the corrosion product diffusion behavior of the embedded sacrificial anode in simulated concrete pore solution and in concrete components subjected to chloride salt attack.Results showed that in simulated concrete pore solution,the embedded sacrificial anode was able to fully polarize the steel reinforcement within 6 h.During the service period,the steel reinforcement potential consistently remained more negative than-780 mV,without exceeding the hydrogen evolution potential.In concrete components,the embedded sacrificial anode achieved 80%polarization of the steel reinforcement within 6 h.A single an-ode provided a stable output current of 0.4 mA,with a current density of 12.74 mA/m^(2).As the distance between the embedded sacrificial an-ode and the steel reinforcement measurement point increased,the polarization degree of the steel reinforcement decreased,resulting in a re-duced protective effect.The maximum protection distance was determined to be 80 cm.The corrosion products of the anode exhibited diffusive behavior and were distributed as fine white particles within the mortar pores,which could reduce the risk of concrete cracking caused by the ex-pansion of corrosion products.
作者
杨未来
赵荣欣
陈宁
吴华勇
徐宁
YANG Weilai;ZHAO Rongxin;CHEN Ning;WU Huayong;XU Ning(Shanghai Building Science Research Institute Co.,Ltd.,Shanghai 200032,China;China MCC20 Group Co.,Ltd.,Shanghai 201900,China)
出处
《材料保护》
2025年第7期165-171,共7页
Materials Protection
基金
上海市“科技创新行动计划”技术标准项目(23DZ2204000)
上海建科集团股份有限公司科研创新项目(KY10000038.20230059)。
关键词
埋入式牺牲阳极
既有钢筋混凝土结构
极化
电位
腐蚀产物
embedded sacrificial anode
existing reinforced concrete structure
polarization
potential
corrosion product
