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Thermal/Acoustical Insulation and Interior Wall/Ceiling Materials
Published in Kathleen Hess-Kosa, Building Materials, 2017
Cementitious foam, a cement-like metal insulation, is fireproof as well as pesticide and mold resistant. First introduced around 1990, cementitious foam (e.g., Air Krete®) has had a slow start—slightly more costly than polyurethane foam in terms of material and installation. The product is made of magnesium oxide, water, and air with some calcium and alumina in the absence of Portland cement. The manufacturers allege no irritant/toxic emissions both during and after application—no VOCs, no formaldehyde.
Creating functionally graded concrete materials with varying 3D printing parameters
Published in Virtual and Physical Prototyping, 2022
Yi Wei Daniel Tay, Jian Hui Lim, Mingyang Li, Ming Jen Tan
Oxman, Keating, and Tsai (2011) designed and produced a rapid fabrication apparatus to vary the properties of the cellular material, as shown in Figure 2. The work focuses on cementitious foam material, where the density is controlled by the production of hydrogen gas bubbles by the reaction of the aluminium powder and lime. The results show that a graded beam with 9% less mass can support the same load as a solid beam of the same size. Besides using the material chemical reaction, a liner density gradient concrete can be created with mechanical means (Choudhry, Panda, and Kumar 2022; Roesler et al. 2007). A compacting equipment can create a smooth graded concrete in the transition zone between the different mixtures with different material strengths. As shown in Figure 3, the higher and lower concrete strength layers are mixed with the temping rod. The ultimate strength of this graded material follows closely to the strength of the lower concrete strength layer (Han, Gan, and Pratama 2016). On the other hand, the material stiffness is affected by the lower and high concrete strength layers (Han, Gan, and Pratama 2016). It appears that this lower concrete strength layer failed first upon reaching the ultimate load, while the higher concrete strength layer remained intact after testing (Gan, Aylie, and Pratama 2015).