Fabio E. Furcas , Shishir Mundra , Barbara Lothenbach , Camelia N. Borca , Thomas Huthwelker , Ueli M. Angst
{"title":"The influence of silicon on the formation and transformation of corrosion products","authors":"Fabio E. Furcas , Shishir Mundra , Barbara Lothenbach , Camelia N. Borca , Thomas Huthwelker , Ueli M. Angst","doi":"10.1016/j.cemconres.2024.107554","DOIUrl":null,"url":null,"abstract":"<div><p>Accurate model predictions of corrosion-driven damage in reinforced concrete structures necessitate a comprehensive understanding of the rate of corrosion product formation. Here, we investigate the influence of dissolved Si characteristic of cementitious systems on the rate of corrosion product transformation at alkaline pH. Compared to systems aged in the absence of Si, small amounts of Si decrease the formation rate of the thermodynamically stable corrosion product goethite by a factor of 10. The estimated first order rate constant of transformation <span><math><mi>k</mi></math></span> decreases exponentially as a function of the dissolved Si concentration and follows the progression <span><math><mrow><msub><mrow><mtext>log</mtext></mrow><mrow><mn>10</mn></mrow></msub><mi>k</mi><mo>=</mo><msub><mrow><mtext>log</mtext></mrow><mrow><mn>10</mn></mrow></msub><msub><mrow><mi>k</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>−</mo></mrow></math></span> 14.65×[Si]<span><math><msup><mrow></mrow><mrow><mn>0</mn><mo>.</mo><mn>28</mn></mrow></msup></math></span>. Findings further suggest that the observed retardation is primarily due to the formation of a mobile aqueous Fe-Si complex. The concentration of Si in cementitious systems has a crucial influence, and additional research is required to fully incorporate this factor into reactive transport models, ultimately essential for accurate service life predictions.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":null,"pages":null},"PeriodicalIF":10.9000,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0008884624001352/pdfft?md5=e7314fb7d7ab9a163e051ab7f9d52a16&pid=1-s2.0-S0008884624001352-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cement and Concrete Research","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0008884624001352","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
Abstract
Accurate model predictions of corrosion-driven damage in reinforced concrete structures necessitate a comprehensive understanding of the rate of corrosion product formation. Here, we investigate the influence of dissolved Si characteristic of cementitious systems on the rate of corrosion product transformation at alkaline pH. Compared to systems aged in the absence of Si, small amounts of Si decrease the formation rate of the thermodynamically stable corrosion product goethite by a factor of 10. The estimated first order rate constant of transformation decreases exponentially as a function of the dissolved Si concentration and follows the progression 14.65×[Si]. Findings further suggest that the observed retardation is primarily due to the formation of a mobile aqueous Fe-Si complex. The concentration of Si in cementitious systems has a crucial influence, and additional research is required to fully incorporate this factor into reactive transport models, ultimately essential for accurate service life predictions.
期刊介绍:
Cement and Concrete Research is dedicated to publishing top-notch research on the materials science and engineering of cement, cement composites, mortars, concrete, and related materials incorporating cement or other mineral binders. The journal prioritizes reporting significant findings in research on the properties and performance of cementitious materials. It also covers novel experimental techniques, the latest analytical and modeling methods, examination and diagnosis of actual cement and concrete structures, and the exploration of potential improvements in materials.