Synthesis and characterization of 3D-printable geopolymeric foams for thermally efficient building envelope materials
Synthesis and characterization of 3D-printable geopolymeric foams for thermally efficient building envelope materials
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DOI：
10.1016/j.cemconcomp.2019.103377
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发表时间：
2019-11-01
影响因子：
10.5
通讯作者：
Neithalath, Narayanan
中科院分区：
文献类型：
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作者：
Alghamdi, Hussam;Neithalath, Narayanan
本文的重点是3D打印发泡粉煤灰基地质聚合物隔热基质的合成和表征。实施基于表面活性剂的发泡工艺、确保泡沫堵塞过渡并因此确保干燥泡沫的多步混合以及确保足够骨架密度的微结构填充，以开发适合3D打印的发泡悬浮液。随着表面活性剂含量的增加，泡沫悬浮液显示出较低的屈服应力，特别是在泡沫堵塞转变之上。该混合物显示出足够的可挤出性、形状保持性和可构建性。地质聚合物泡沫显示出55 - 75%的孔隙率和0.6 - 1.0g/cm（3）的堆积密度，并且这些性质是相似的，而不管混合物是挤出的还是常规浇铸的。发泡基质的热导率范围为0.15至0.25 W/m-K。它示出，设计的建筑，最大限度地减少热传递可以使用发泡基质打印，以获得隔热性能相当或优于目前可用的隔热混凝土墙板的夹层墙板。这将3D打印定位为开发具有以前无法达到的热性能的复合材料系统的策略。
Synthesis and characterization of 3D-printable foamed fly ash-based geopolymer matrices for thermal insulation is the focus of this paper. A surfactant-based foaming process, multi-step mixing that ensures foam jamming transition and thus a dry foam, and microstructural packing to ensure adequate skeletal density are implemented to develop foamed suspensions amenable to 3D-printing. The foamed suspensions show lower yield stress with increasing surfactant contents, especially above the foam jamming transition. The mixtures demonstrate adequate extrudability, shape retention, and buildability. The geopolymeric foams show porosities ranging from 55 to 75% and bulk densities from 0.6 to 1.0 g/cm(3), and these properties are similar irrespective of whether the mixtures are extruded or conventionally cast. The thermal conductivities of the foamed matrices range from 0.15 to 0.25 W/m-K. It is shown that designed architectures that minimize heat transfer can be printed using foamed matrices to obtain sandwich wall panels with thermal insulation properties comparable to or better than those of currently available insulated concrete wall panels. This positions 3D-printing as a strategy to develop composite systems with previously unattainable thermal performance.