...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Crystal growth & design >Computed X-ray Tomography Study of Carbonate Precipitation in Large Portland Cement Pores
【24h】

Computed X-ray Tomography Study of Carbonate Precipitation in Large Portland Cement Pores

机译：大港水泥毛孔中碳酸盐沉淀的计算X射线断层扫描研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Cement degradation caused by CO2 exposure is an increasingly important environmental challenge that must be understood, for example, if former oil reservoirs are to be used for CO2 storage. When exposed to CO2-saturated brine, cement undergoes a chemically complex carbonation process that influences all the physicochemical properties of the cement. It is known that under favorable conditions, fractures and voids in cement can be occluded, or self-sealed, by precipitation of calcium carbonate. Here, we report a detailed X-ray microcomputed tomography (mu-CT) study on the carbonation of gas pores (macropores) of diameter similar to 1 mm in cement. Specifically, cured class G Portland cement with sub-millimeter spherical disconnected macropores was exposed to CO2-saturated brine at high pressure (280 bar) and high temperature (90 degrees C) for 1 week. High-resolution synchrotron-based mu-CT enabled visualizing the morphology of the precipitates inside the macropores within both unreacted and carbonated regions. Quantitative analysis of the type and amount of material deposited in the macropores during carbonation suggests that the filling of the disconnected macropores involves transport of calcium ions from the cement bulk to the macropore interior. A detailed model describing the chemical processes involved is provided. The present study gives a deeper understanding of cement carbonation by literally shedding light on the complex precipitate structures within the macropores.
机译：二氧化碳暴露引起的水泥降解是一种越来越重要的环境挑战，例如，如果以前的油储存器用于CO 2储存，​​则必须理解。当暴露于二氧化碳饱和盐水时，水泥经历化学复杂的碳酸化方法，其影响水泥的所有物理化学性质。众所周知，在良好的条件下，可以通过碳酸钙的沉淀来堵塞或自密封水泥的裂缝和空隙。在这里，我们报告了一种详细的X射线微仿性断层扫描（MU-CT）研究直径的气体孔（Macropores）的碳酸化，其水泥中的1mm。具体地，具有亚毫米球形断开的大孔的固化类G波特兰水泥在高压（280巴）和高温（90℃）下暴露于CO 2饱和盐水1周。基于高分辨率的同步rotron的MU-CT使能可视化未反应和碳酸区域内的大孔内的沉淀物的形态。在碳酸化过程中沉积在大孔中沉积物的类型和量的定量分析表明，断开的大孔的填充涉及将钙离子与水泥体积的运输到大孔内部。提供了描述所涉及的化学过程的详细模型。本研究通过对大麦内的复杂沉淀结构的光线脱落，更深入地了解水泥碳化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号