Engineering of high specific strength and low thermal conductivity cementitious composites with hollow glass microspheres for high-temperature high-pressure applications
Engineering of high specific strength and low thermal conductivity cementitious composites with hollow glass microspheres for high-temperature high-pressure applications
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DOI：
10.1016/j.cemconcomp.2020.103514
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发表时间：
2020-04-01
影响因子：
10.5
通讯作者：
Qomi, Mohammad Javad Abdolhosseini
中科院分区：
文献类型：
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作者：
Krakowiak, Konrad J.;Nannapaneni, Raj Gopal;Qomi, Mohammad Javad Abdolhosseini
具有高比强度和低导热性的轻质水泥基复合材料在能源和建筑行业受到高度追捧。这些特性对于设计高温高压井（HTHP）的水泥衬管非常重要，也适用于在永久冻土中作业的井。在设计节能建筑围护结构的胶凝复合材料时，也需要类似的属性。这项工作报告了一项实验活动的结果，该活动的重点是工程轻质胶凝复合材料与中空玻璃微球。结果表明，通过调节硅质助剂的比表面积和溶解速率常数，可以直接控制微球在高温高压条件下的化学稳定性。除了稳定作用外，这些添加剂还导致孔隙结构细化和界面过渡区（ITZ）的增强。引入的轻质复合材料在正常固化时能够提供显着的承载能力，这是通过水热固化大大增加的。这种高比强度复合材料在烘箱干密度下的导热系数低于0.3 W/mK
Lightweight cement-based composites with high specific strength and low thermal conductivity are highly sought in the energy and construction industries. These characteristics are important in designing cement liners for high-temperature, high-pressure (HTHP) wells, in addition to those operating in permafrost. Similar attributes are also desirable in designing cementitious composites for energy efficient building envelopes. This work reports the results of an experimental campaign focused on engineering lightweight cementitious composites with hollow glass microspheres. It is demonstrated that the chemical stability of microspheres at HTHP conditions can be directly controlled by modulating the specific surface area and dissolution rate constant of supplementary siliceous additives. In addition to the stabilizing effect, such additives lead to the pore structure refinement and the enhancement of interfacial transition zone (ITZ). Introduced lightweight composites are capable of delivering significant load bearing capacity when normally cured, which is greatly increased by hydrothermal curing. Such high specific strength composites possess thermal conductivity below 0.3 W/mK at the oven dry density