基于第一性原理的水氧相互作用下混凝土中钢筋锈蚀机理研究  

Study on the corrosion mechanism of reinforcement in concrete with interaction of water and oxygen based on first-principles

作　　者：农喻媚 陈正[1,2] NONG Yumei;CHEN Zheng(Key Laboratory of Engineering Disaster Prevention and Structural Safety of China Ministry of Education,School of Civil Engineering and Architecture,Nanning 530004,China;Guangxi Key Laboratory of Disaster Prevention and Structural Safety,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学土木建筑工程学院工程防灾与结构安全教育部重点实验室,广西南宁530004 [2]广西大学广西防灾减灾与工程安全重点实验室,广西南宁530004

出　　处：《混凝土》2020年第5期24-27,共4页Concrete

基　　金：国家自然科学基金项目(51468004);广西自然科学基金项目(2015GXNSFBB139011);广西科技开发项目(桂科转15989-10)。

摘　　要：为了阐明水氧相互作用下钢筋锈蚀的机理,采用基于第一性原理的密度泛函理论,建立了O2分子和H2O分子在Fe(100)表面的吸附模型,研究分析了各吸附体系的吸附能、几何结构和电荷变化.结果表明,H2O分子与清洁Fe(100)表面之间是弱的物理吸附作用,而在Fe(100)表面预先吸附O2分子,可通过氢键作用促进后续H2O分子的吸附;O2分子在预吸附H2O分子的Fe(100)表面上的吸附是很强的化学吸附作用.由此可见,相比于H2O分子单独作用于铁表面,H2O和O2分子相互作用对铁表面腐蚀的影响更大,从微观尺度证明了与水下区相比,处于干湿交替环境的浪溅区混凝土结构中钢筋的腐蚀更为严重。In order to clarify the corrosion mechanism of reinforcement with the interaction of H2O and O2,the adsorption energies,configuration and charge variation of O2 and H2O adsorbed on Fe(100)surface were studied by density functional theory based on first-principles.The results suggest that the interaction between H2O molecule and Fe(100)surface is a weak physisorption,while the preadsorbed oxygen could strengthen the adsorption of H2O via the formation of hydrogen bond between oxygen O and water H atoms.The adsorption of O2 on water-preadsorbed Fe(100)surface is a strong chemisorption.Thereby,comparing to the adsorption of single H2O on Fe(100)surface,the interaction of H2O and O2 affect more seriously on the corrosion of iron surface,which proves from the microscopic scale that the corrosion of reinforcement in the splash zone is more serious than that in the seawater full immersion zone.

关 键 词：第一性原理 钢筋锈蚀机理 水氧作用 干湿交替 

分 类 号：TU528.01[建筑科学—建筑技术科学]