Physical and Mechanical Response of the Cementation of Aluminosilicate Seals

硅铝酸盐密封胶结的物理和机械响应

• 批准号: 2149529
• 负责人: Tiziana Vanorio
• 金额: $ 50万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2149529&HistoricalAwards=false
• 关键词: Physical; Mechanical; Response; Cementation; Aluminosilicate

For decades, geophysicists studying faults and earthquakes have focused on how rocks weaken or break in response to forces within the Earth. Another question we need to ask is, how do rocks restrengthen, for instance, between earthquakes? One process that makes rocks stronger is cementation. That is, groundwater passing through small pores and cracks in rocks may deposit minerals which act like glue or cement, strengthening the rock. Dr. Vanorio and her group will conduct laboratory studies to investigate in detail just how cements form, and how much they strengthen rocks under a variety of thermal and chemical conditions. In addition to helping scientists understand how faulted rocks rebuild their strength between earthquakes, Dr. Vanorio's research can also help engineers design materials that can maintain their strength under harsh chemical conditions over long periods of time. Because cementation fills small voids in rock and makes them more impervious to fluid flow, her research will also help engineers to design geothermal systems or select suitable sealed reservoirs for storing greenhouse gases.Active faults of the Earth's crust function as large-scale kiln factories — they mechanically pulverize aluminosilicate rocks to the micron or finer scale, and internally channel heat that treats and primes the fault gouge for fluid-mediated chemical reactions, eventually leading to cementation. Geophysical data shows that repeated failures and strength recovery of the Earth’s crust — a process known as fault healing, is a relatively fast process. In this project, the PI intends to advance knowledge on the natural cementation (i.e., frictional healing) of geological seals by studying Earth’s chemical synthesis of aluminosilicates exposed to two natural processes: CO2-induced carbonation and alkaline hydrothermal treatment. To understand how the physical and mechanical properties of rock materials measured at the macro scale connect to the underlying structure, the PI plans to study the micro- and nano-scale structures of the formed cementitious phases and how they influence strength and mode of failure as well as the acoustic signature of the loss of seal integrity (crack propagation and fracturing).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

几十年来，研究断层和地震的地球物理学家一直专注于岩石如何减弱或破裂，以响应地球内部的力。我们需要问的另一个问题是，例如，在地震之间，岩石是如何重新加固的？胶结作用是使岩石变得更坚固的一个过程。也就是说，地下水穿过岩石中的小孔隙和裂隙，可能会沉积起胶水或水泥作用的矿物，从而加固岩石。瓦诺里奥博士和她的团队将进行实验室研究，详细研究水泥是如何形成的，以及它们在各种热和化学条件下对岩石的加固程度。除了帮助科学家了解断层岩石如何在地震中恢复强度外，瓦诺里奥博士的研究还可以帮助工程师设计出能够在恶劣的化学条件下长期保持强度的材料。由于胶结作用填充了岩石中的小空隙，使它们更不受流体流动的影响，她的研究还将帮助工程师设计地热系统或选择合适的密封储气库来储存温室气体。地壳活动的断层像大型窑厂一样发挥作用-它们将铝硅酸盐岩石机械粉碎到微米或更细的尺度，并在内部通过通道热量处理断层泥，以进行流体中介的化学反应，最终导致胶结作用。地球物理数据显示，地壳的反复破裂和强度恢复--一个被称为断层愈合的过程，是一个相对较快的过程。在这个项目中，PI打算通过研究地球上暴露在两个自然过程中的铝硅酸盐的化学合成来促进对地质盖层的自然胶结(即摩擦愈合)的认识：二氧化碳诱导的碳化和碱性水热处理。为了了解在宏观尺度上测量的岩石材料的物理和机械性能如何与底层结构相关联，PI计划研究形成的胶结相的微观和纳米尺度结构，以及它们如何影响强度和失效模式，以及密封完整性丧失(裂缝扩展和破裂)的声学特征。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。