Durability control of sea-sand concrete components utilizing strong electric field during early curing period
Durability control of sea-sand concrete components utilizing strong electric field during early curing period
复制标题
利用强电场控制海砂混凝土构件养护初期的耐久性
DOI：
10.1016/j.conbuildmat.2022.128221
复制
发表时间：
2022-07-01
影响因子：
7.4
通讯作者：
Jin，Libing
中科院分区：
文献类型：
--
作者：
Fang，Kun;Mao，Jianghong;Jin，Libing
电化学氯离子提取技术可以有效地降低混凝土结构中有害氯离子的含量，从而降低其耐久性失效风险。通过强电场作用，将电化学法应用于氯离子含量超标的海砂混凝土。进一步测试了混凝土柱的氯离子含量、细观力学性能和力学性能，验证了混凝土柱在强电场作用后的耐久性能。结果表明，对于养护时间分别为3、5和7天的早龄期混凝土，强电场通电时间分别为40、80和120天时，可以显著提高混凝土的电火花效率，混凝土的氯离子含量能够满足规范要求。在养护过程中，与未带电混凝土构件相比，带电构件在强电场作用后立即加载时，带电构件在相同荷载下的应变和位移均有所增加。然而，施加电场后，如果构件标准养护28天，其极限承载能力提高，力学性能改善。养护28天后，ECEC-3、ECEC-5和ECEC-7的承载能力分别为315.2kN、320.1kN和340.9kN，与ECEC-28的326.2kN相近。针对电场对塔体性能的不利影响，设计了避免氢脆和塑化的技术方案。
Electrochemical chloride extraction (ECE) technology can effectively reduce the harmful chloride ion content of concrete structures and thus decrease their durability failure risk. This paper applied the ECE technology to sea-sand concrete with an excessive chloride ion content through a strong electric field. Further, testing the chloride ion content, meso- and micro-mechanical properties, and mechanical performance of the concrete columns verified their durability performance after the action of the strong electric field. The results show that, for the early-age concrete with a curing period of 3, 5, and 7 days, the strong electric field with an electrifying time of 40, 80, and 120 min can significantly enhance the ECE efficiency, and the chloride ion content of the concrete can fulfill the specification requirements. During the curing period, compared with the unelectrified concrete components, the strain and displacement of the electrified columns increase under the same load when the components are loaded immediately after the action of the strong electric field. However, after applying the electric field, if the member is standardly cured for 28 days, its ultimate bearing capacity increases, and its mechanical properties improve. The bearing capacity of ECEC-3, ECEC-5 and ECEC-7 after curing 28 days are 315.2kN, 320.1kN and 340.9kN which are closed to 326.2kN of ECEC-28. Regarding the adverse effect of the electric field on the performance of the columns, a technical scheme was designed to avoid their hydrogen embrittlement and plastic reduction.