Su Zijian, Hou Wei, Sun Zengqing, Lv Wei
School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
Institute of Building Materials Research (IBAC), Rheinisch-Westfälische Technische Hochschule Aachen University, Schinkelstr. 3, 52062 Aachen, Germany.
Materials (Basel). 2020 Sep 12;13(18):4059. doi: 10.3390/ma13184059.
Foamed fly ash geopolymer was synthesized in this work to produce geopolymeric lightweight concrete (GLWC). Fly ash was activated by sodium silicate solution, and aluminum powder was employed as an in situ chemical foaming agent. The synthesized pastes were cured at 40 °C for 28 days, with bulk densities of resultant GLWCs ranging from 600 to 1600 kg/m. The resulting mechanical properties, thermal conductivity, microstructure, and reaction product were fully characterized. Results show that GLWC had higher mechanical strength than commercial aerated concrete and developed 80-90% of its corresponding 28 days strength after curing for 7 days. For densities from 1200 to 600 kg/m, the thermal conductivity diminished from 0.70 to 0.22 W/mK, which is much better than that of its counterpart, ordinary Portland cement (OPC). Scanning electron microscopy (SEM) images revealed decent matrices comprising geopolymeric gel and unreacted fly ash.
在本研究中合成了泡沫粉煤灰地质聚合物，以制备地质聚合物轻质混凝土（GLWC）。用硅酸钠溶液激发粉煤灰，并使用铝粉作为原位化学发泡剂。合成的浆体在40℃下养护28天，所得GLWC的堆积密度范围为600至1600kg/m³。对所得的力学性能、导热系数、微观结构和反应产物进行了全面表征。结果表明，GLWC的机械强度高于商用加气混凝土，养护7天后其强度达到相应28天强度的80-90%。对于密度从1200至600kg/m³的情况，导热系数从0.70降低至0.22W/mK，这比其对应物普通硅酸盐水泥（OPC）要好得多。扫描电子显微镜（SEM）图像显示出由地质聚合物凝胶和未反应的粉煤灰组成的良好基体。
