EAGER: Corrosion Reduction in Reinforcing Steel of Concrete Structures through Grain Size Alteration

EAGER：通过改变晶粒尺寸减少混凝土结构钢筋的腐蚀

• 批准号: 1552794
• 负责人: Amir Poursaee
• 金额: $ 15.41万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1552794&HistoricalAwards=false
• 关键词: EAGER; Corrosion; Reduction; Reinforcing; Steel

Corrosion of reinforcing steel in concrete structures is one of the critical parameters in deterioration of concrete structures. It is hypothesized that reduction in grain size in steel can significantly reduce corrosion in reinforcing bars. Analytical and experimental studies will be pursued to correlate between grain size and level of corrosion. The experiments in this EArly-concept Grant for Exploratory Research (EAGER) project will include putting the reinforcing steel in the simulated concrete environment. The grain size in steel will be altered using thermal cycles to determine effects of grain size on corrosion and mechanical properties. The reinforcing steel will be subjected to chloride contaminated concrete pore solution and the level of corrosion on the corroded steel bars will be assessed using different microscopic and spectroscopic analyses. Mechanical properties of the steel with different grain sizes will be obtained with standard tests. Cost analysis of the alteration of grain size will be pursued in this exploratory project to determine viability of the process.Electron backscatter diffraction technique to obtain quantitative microstructural map will be used for crystallographic nature of the steel specimens. This technique reveals grain size, grain boundary character, grain orientation, texture, and phase identity of the specimens. The microstructural map in an analytical model will allow predicting the pitting corrosion behavior of steel with different grain sizes. Physical and chemical composition of the steel will be obtained using scanning electrochemical microscopy, X-ray photoelectron spectroscopy, and optical profiler. The analytical model will include pitting growth as a variable. Life cycle cost analysis will be pursued as related to grain size necessary to reduce corrosion. A procedure that is in a standard for cost analysis for measuring life cycle costs in buildings will be used for this purpose. The final results of this exploratory project will be to understand corrosion as related to grain size of steel exposed to environment of concrete.

混凝土结构中加固钢的腐蚀是混凝土结构恶化的关键参数之一。假设钢中晶粒尺寸的减少可以显着减少加固棒中的腐蚀。将进行分析和实验研究以在晶粒尺寸和腐蚀水平之间相关。这项早期概念研究的实验（急切）项目将包括将增强钢放在模拟的混凝土环境中。钢中的晶粒尺寸将使用热循环改变，以确定晶粒尺寸对腐蚀和机械性能的影响。钢筋将进行氯化物污染的混凝土孔隙溶液，并将使用不同的显微镜和光谱分析评估腐蚀钢筋上的腐蚀水平。具有不同晶粒尺寸的钢的机械性能将通过标准测试获得。在此探索性项目中，将对晶粒大小改变的成本分析以确定过程的可行性。电子反向散射技术以获取定量微观结构图的衍射技术将用于钢试样的晶体学性质。该技术揭示了晶粒尺寸，晶界特征，晶粒方向，纹理和样品的相位身份。分析模型中的微观结构图将允许预测具有不同晶粒尺寸的钢的点腐蚀行为。钢的物理和化学组成将使用扫描电化学显微镜，X射线光电子光谱和光学探测器获得。分析模型将包括将增长作为变量。生命周期成本分析将与减少腐蚀所需的晶粒尺寸相关。用于测量建筑物生命周期成本的成本分析标准的程序将用于此目的。该探索性项目的最终结果将是了解与暴露于混凝土环境的钢的晶粒尺寸有关的腐蚀。