Recently, energy conservation through building thermal insulation has gained significant importance in solving sustainability-related issues. In this context, this study investigates the potential for manufacturing geopolymer foam concrete (GFC) containing eggshell powder (ESP) and sawdust ash (SDA) using aluminium (Al) powder as a foaming agent. The role of Al-powder percentages on the mechanical and thermal properties of GFC was thoroughly investigated. The effect of ESP and SDA incorporation as partial replacements of precursors (from 0 to 20 %) on the thermal properties, durability, and microstructure of GFCs were also discussed. The experimental findings demonstrate that the bulk density and compressive strength of GFC with different Al-powder contents ranged between 1928 and 1798 kg/m and 17.45 and 9.37 MPa, respectively. The SEM images and MIP tests show that foams with different numbers of micro- and macropores are formed in GFCs. The ESP-based GFC had an apparent porosity range of 13.09 %–10.29 % and a bulk density range of 1823 to 1713 kg/m. The SDA-based GFC had an apparent porosity range of 14.21 %–12.96 % and a bulk density range of 1834 to 1807.8 kg/m. It was found that the 10 % ESP and 5 %, SDA mixtures enhanced the strength by 16.54 % and 4.45 %, respectively, compared to the control mix. The thermal conductivity, thermal diffusivity, and specific heat of 10 % ESP-mixture and 5 % SDA-mixture were 1.237 and 1.167 W/(mK), 0.795 and 0.922 mm/S, and 1.556 and 1.266 MJ/mK, respectively. Finally, the residual strength and microstructure investigations demonstrate that ESP-based GFCs have more stability than SDA-based GFCs and the control mix when subjected to elevated temperatures.

中文翻译：

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锯末灰蛋壳地聚物泡沫混凝土的物理力学、保温性能及微观结构

最近，通过建筑隔热实现节能在解决可持续发展相关问题方面变得非常重要。在此背景下，本研究探讨了使用铝 (Al) 粉作为发泡剂制造含有蛋壳粉 (ESP) 和锯末灰 (SDA) 的地质聚合物泡沫混凝土 (GFC) 的潜力。深入研究了铝粉百分比对 GFC 机械和热性能的影响。还讨论了 ESP 和 SDA 的掺入作为前驱体的部分替代（0 至 20%）对 GFC 的热性能、耐久性和微观结构的影响。实验结果表明，不同铝粉含量的GFC的堆积密度和抗压强度分别在1928~1798 kg/m、17.45~9.37 MPa之间。 SEM 图像和 MIP 测试表明，GFC 中形成了具有不同数量的微孔和大孔的泡沫。基于 ESP 的 GFC 的表观孔隙度范围为 13.09%–10.29%，堆积密度范围为 1823 至 1713 kg/m。基于 SDA 的 GFC 的表观孔隙度范围为 14.21%–12.96%，堆积密度范围为 1834 至 1807.8 kg/m。结果发现，与对照混合物相比，10% ESP 和 5% SDA 混合物的强度分别提高了 16.54% 和 4.45%。 10% ESP 混合物和 5% SDA 混合物的导热系数、热扩散系数和比热分别为 1.237 和 1.167 W/(mK)、0.795 和 0.922 mm/S、1.556 和 1.266 MJ/mK。最后，残余强度和微观结构研究表明，在高温下，基于 ESP 的 GFC 比基于 SDA 的 GFC 和对照混合物具有更高的稳定性。