POWRE: Examination of the Mechanisms of ASR Gel Expansion Control by Lithium Additive in Concrete

POWRE：混凝土中锂添加剂控制 ASR 凝胶膨胀机制的研究

• 批准号: 0074874
• 负责人: Kimberly Kurtis
• 金额: $ 7.5万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2002-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0074874&HistoricalAwards=false
• 关键词: POWRE; Examination; Mechanisms; ASR; Gel

0074874KurtisA POWRE award will support a study of the effects of lithium additives to control expansion by alkali-silica reaction (ASR) in concrete. This reaction occurs between reactive silicates present in some aggregate and pore solution alkalis and produces an alkali-silica gel that is capable of expansion, damaging the affected concrete structure. A more thorough understanding of the mechanisms of expansion control will provide the basis for determining which additives in which dosages should be used in new and existing concrete structures to avoid damage by the reaction. This proposed research is critical for this investigator at this early stage in her career as it will allow her to launch a new research area while building upon her existing knowledge and skills.A key component of the proposed research is the development of the novel application of laser scanning confocal microscopy (LSCM) to examine cement-based materials. Examination of cement-based materials by confocal microscopy has been relatively unexplored, but this technique offers much promise because of the flexible sample preparation requirements, high resolution, and ability to generate three-dimensional representations. Because of their visual impact, these three-dimensional models can be used advantageously in both technical education and public outreach, and several activities have been proposed including the development of two brief tutorials (one appropriate for university education; one appropriate for K-12 education). By demonstrating the utility of this microscopy technique for through-depth examination of concrete to study the alkali-silica reaction, LSCM will find wider applications in concrete technology. Development and refinement of sample preparation protocols, observation methods, and representation formats would establish the investigator as a leader in innovative microscopy of cement-based materials and could lead to additional funding opportunities for the PI.***

0074874KurtisA POWRE奖将支持一项关于锂添加剂控制混凝土中碱-硅反应(ASR)膨胀的影响的研究。这种反应发生在某些骨料中的活性硅酸盐和孔隙溶液碱之间，并产生一种能够膨胀的碱-硅胶，破坏受影响的混凝土结构。更透彻地了解膨胀控制机理将为确定在新的和现有的混凝土结构中使用哪些外加剂和不同剂量的外加剂以避免反应造成损害提供基础。这项拟议的研究对这位处于职业生涯早期阶段的研究员来说至关重要，因为它将使她能够在建立现有知识和技能的同时启动一个新的研究领域。拟议研究的一个关键组成部分是开发激光扫描共聚焦显微镜(LSCM)检测水泥基材料的新应用。用共聚焦显微镜检查水泥基材料相对来说还没有被探索过，但是这项技术提供了很大的前景，因为它具有灵活的样品制备要求、高分辨率和生成三维表示的能力。由于其视觉效果，这些三维模型可用于技术教育和公共宣传，并已提议开展若干活动，包括编写两个简短的教程(一个适用于大学教育；一个适用于K-12教育)。通过展示这种显微技术对混凝土进行深入研究以研究碱-硅酸反应的有效性，激光扫描共聚焦显微镜将在混凝土技术中得到更广泛的应用。样品制备方案、观察方法和表示格式的开发和改进将使研究人员成为水泥基材料创新显微镜领域的领导者，并可能为PI带来更多的资金机会。