Minimization of the Stresses Generated by ICE Formation in Concrete

混凝土中的结冰是寒冷地区混凝土结构每年造成数百万美元损失的原因。这项提议利用新的复杂的表征技术来开发一个全面的计划。在微观层面上，将使用中子衍射来确定胶凝基质中可冻结水的含量，并确定冻结时基质中的原地应力和应变场。在细观水平上，将使用高分辨率低温扫描电子显微镜来研究不同类型的化学外加剂对气孔形态的影响，并表征冰结晶的成核位置。。在宏观层面上，将使用大的混凝土样本来验证在微观和中观层面上学到的观察结果。

Ice formation in concrete is the cause of millions of dollars in damage to concrete structures in cold regions every. This proposal takes advantage of new sophisticated characterization techniques to develop a holistic program. At a microscopic level, neutron diffraction will be used to determine the content of freezable water in the cementitious matrix, and to determine the in-situ stress and strain field in the matrix as it freezes. At a meso level, high resolution low-temperature scanning electron microscopy will be employed to study the air-void morphology as affected by the type of chemical admixtures and to characterize the nucleation sites of ice crystallization. . At the macro level, large concrete samples will be used to validate the observations learned at the micro and meso level.