现场分析揭示了钙离子悖论：延迟钝化而增强混凝土中钢筋的耐久性

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials Pub Date : 2025-10-10 DOI:10.1016/j.conbuildmat.2025.143971

Zuquan Jin , Zheng Li , Lihang Qian , Haosen Jiang , Xiaotong Wang , Ning Li , Xiaoying Zhang

{"title":"现场分析揭示了钙离子悖论：延迟钝化而增强混凝土中钢筋的耐久性","authors":"Zuquan Jin , Zheng Li , Lihang Qian , Haosen Jiang , Xiaotong Wang , Ning Li , Xiaoying Zhang","doi":"10.1016/j.conbuildmat.2025.143971","DOIUrl":null,"url":null,"abstract":"<div><div>The nanoscale passive films (PF) on steel surface serve as the fundamental factor for reinforced concrete's corrosion resistance and durability. However, it is a challenge to elucidate the composition and formation mechanism of PF due to its intrinsic instability and constraints of conventional characterization techniques. In-situ GIXRD and electrochemical analysis was introduced to elucidate cation effects (Na+/K+/Ca2+) on PF composition, formation kinetics, reaction mechanisms and corrosion resistance in concrete pore solutions. Within pH 12.5 alkaline solution (NaOH/KOH/Ca(OH)2), Na+/K+/Ca2+ drive passivation on pure Fe, where Na3Fe5O9, K6Fe2O6, and CaFe2O4 emerge as distinct dominant components. In addition, PF formation kinetics varied significantly among cations: complete film formation required 120 h in Ca(OH)2 solution vs. 48 h in NaOH and KOH solutions, suggesting distinct reaction pathways. Passivation in NaOH/KOH involves three steps (Fe0→Fe+, Fe+→Fe2+, and Fe2+→Fe3+), while Ca(OH)2 follows a two-step process (Fe0→Fe+ and Fe+→Fe3+). Paradoxically, despite its slower kinetics, the Ca2+-derived PF demonstrates significantly superior corrosion resistance (Ca(OH)2 > NaOH > KOH). This work systematically elucidates the mechanisms underlying this delayed passivation yet enhanced durability phenomenon associated with Ca2+, providing crucial insights for improving concrete structure durability.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"498 ","pages":"Article 143971"},"PeriodicalIF":8.0000,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"In-situ analysis reveals the calcium ion paradox: Delayed passivation yet enhanced durability of rebar in concrete\",\"authors\":\"Zuquan Jin , Zheng Li , Lihang Qian , Haosen Jiang , Xiaotong Wang , Ning Li , Xiaoying Zhang\",\"doi\":\"10.1016/j.conbuildmat.2025.143971\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The nanoscale passive films (PF) on steel surface serve as the fundamental factor for reinforced concrete's corrosion resistance and durability. However, it is a challenge to elucidate the composition and formation mechanism of PF due to its intrinsic instability and constraints of conventional characterization techniques. In-situ GIXRD and electrochemical analysis was introduced to elucidate cation effects (Na+/K+/Ca2+) on PF composition, formation kinetics, reaction mechanisms and corrosion resistance in concrete pore solutions. Within pH 12.5 alkaline solution (NaOH/KOH/Ca(OH)2), Na+/K+/Ca2+ drive passivation on pure Fe, where Na3Fe5O9, K6Fe2O6, and CaFe2O4 emerge as distinct dominant components. In addition, PF formation kinetics varied significantly among cations: complete film formation required 120 h in Ca(OH)2 solution vs. 48 h in NaOH and KOH solutions, suggesting distinct reaction pathways. Passivation in NaOH/KOH involves three steps (Fe0→Fe+, Fe+→Fe2+, and Fe2+→Fe3+), while Ca(OH)2 follows a two-step process (Fe0→Fe+ and Fe+→Fe3+). Paradoxically, despite its slower kinetics, the Ca2+-derived PF demonstrates significantly superior corrosion resistance (Ca(OH)2 > NaOH > KOH). This work systematically elucidates the mechanisms underlying this delayed passivation yet enhanced durability phenomenon associated with Ca2+, providing crucial insights for improving concrete structure durability.</div></div>\",\"PeriodicalId\":288,\"journal\":{\"name\":\"Construction and Building Materials\",\"volume\":\"498 \",\"pages\":\"Article 143971\"},\"PeriodicalIF\":8.0000,\"publicationDate\":\"2025-10-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Construction and Building Materials\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0950061825041224\",\"RegionNum\":1,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CONSTRUCTION & BUILDING TECHNOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Construction and Building Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0950061825041224","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}

引用次数: 0

摘要

钢表面纳米钝化膜是影响钢筋混凝土耐蚀性和耐久性的重要因素。然而，由于其固有的不稳定性和传统表征技术的限制，阐明PF的组成和形成机制是一个挑战。采用原位GIXRD和电化学分析方法研究了Na+/K+/Ca2+对混凝土孔隙溶液中PF组成、形成动力学、反应机理和耐蚀性的影响。在pH为12.5的碱性溶液（NaOH/KOH/Ca(OH)2）中，Na+/K+/Ca2+驱动纯铁钝化，其中Na3Fe5O9、K6Fe2O6和CaFe2O4是明显的主导成分。此外，PF的形成动力学在不同阳离子之间有显著差异：在Ca(OH)2溶液中完全形成膜需要120 h，而在NaOH和KOH溶液中需要48 h，这表明不同的反应途径。NaOH/KOH的钝化过程分为三个步骤（Fe0→Fe+, Fe+→Fe2+, Fe2+→Fe3+），而Ca(OH)2则分为两个步骤（Fe0→Fe+, Fe+→Fe3+）。矛盾的是，尽管其动力学较慢，Ca2+衍生的PF表现出明显优越的耐腐蚀性（Ca(OH)2 > NaOH >； KOH）。这项工作系统地阐明了与Ca2+相关的延迟钝化但增强耐久性现象的机制，为提高混凝土结构耐久性提供了重要的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

查看原文本刊更多论文

In-situ analysis reveals the calcium ion paradox: Delayed passivation yet enhanced durability of rebar in concrete

The nanoscale passive films (PF) on steel surface serve as the fundamental factor for reinforced concrete's corrosion resistance and durability. However, it is a challenge to elucidate the composition and formation mechanism of PF due to its intrinsic instability and constraints of conventional characterization techniques. In-situ GIXRD and electrochemical analysis was introduced to elucidate cation effects (Na⁺/K⁺/Ca²⁺) on PF composition, formation kinetics, reaction mechanisms and corrosion resistance in concrete pore solutions. Within pH 12.5 alkaline solution (NaOH/KOH/Ca(OH)₂), Na⁺/K⁺/Ca²⁺ drive passivation on pure Fe, where Na₃Fe₅O₉, K₆Fe₂O₆, and CaFe₂O₄ emerge as distinct dominant components. In addition, PF formation kinetics varied significantly among cations: complete film formation required 120 h in Ca(OH)₂ solution vs. 48 h in NaOH and KOH solutions, suggesting distinct reaction pathways. Passivation in NaOH/KOH involves three steps (Fe⁰→Fe⁺, Fe⁺→Fe²⁺, and Fe²⁺→Fe³⁺), while Ca(OH)₂ follows a two-step process (Fe⁰→Fe⁺ and Fe⁺→Fe³⁺). Paradoxically, despite its slower kinetics, the Ca²⁺-derived PF demonstrates significantly superior corrosion resistance (Ca(OH)₂ > NaOH > KOH). This work systematically elucidates the mechanisms underlying this delayed passivation yet enhanced durability phenomenon associated with Ca²⁺, providing crucial insights for improving concrete structure durability.

求助全文

通过发布文献求助，成功后即可免费获取论文全文。去求助

来源期刊

Construction and Building Materials 工程技术-材料科学：综合

CiteScore

13.80

自引率

21.60%

发文量

3632

审稿时长

82 days

期刊介绍： Construction and Building Materials offers an international platform for sharing innovative and original research and development in the realm of construction and building materials, along with their practical applications in new projects and repair practices. The journal publishes a diverse array of pioneering research and application papers, detailing laboratory investigations and, to a limited extent, numerical analyses or reports on full-scale projects. Multi-part papers are discouraged. Additionally, Construction and Building Materials features comprehensive case studies and insightful review articles that contribute to new insights in the field. Our focus is on papers related to construction materials, excluding those on structural engineering, geotechnics, and unbound highway layers. Covered materials and technologies encompass cement, concrete reinforcement, bricks and mortars, additives, corrosion technology, ceramics, timber, steel, polymers, glass fibers, recycled materials, bamboo, rammed earth, non-conventional building materials, bituminous materials, and applications in railway materials.