Wang Dan, Shan Wendong, Li Rongjie, Song Zhiqiang, Guo Lanhui
School of Architectural Engineering, Hulunbuir University, Hulunbuir 021008, China.
School of Civil Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, China.
Materials (Basel). 2025 Aug 13;18(16):3801. doi: 10.3390/ma18163801.
This study develops a novel geopolymer foamed concrete using coal gangue and slag as precursors, along with a composite alkali activator comprising sodium silicate and sodium hydroxide, based on the physical foaming method. The Box-Behnken Design within Response Surface Methodology was applied to optimize the mix proportions of coal gangue-slag-based geopolymer foamed concrete. The effects of alkali activator dosage, sodium silicate modulus, water-to-binder ratio, and foam content on 28-day compressive strength and thermal conductivity were systematically investigated to determine the optimal mix for achieving a balance between mechanical and thermal performance. Scanning Electron Microscopy and other characterization techniques were used to analyze the microstructural features. The results show that foam content has the most significant influence on both mechanical and thermal performance, while the interaction between sodium silicate modulus and foam content exhibits the most pronounced combined effect. The optimized mix design consists of 9.1% alkali activator dosage, a sodium silicate modulus of 1.07, a water-to-binder ratio of 0.44, and foam content of 50%, resulting in a 28-day compressive strength of 2.30 MPa and thermal conductivity of 0.0781 W/(m·K). The observed performance enhancement is primarily attributed to the increased heterogeneity in the pore structure. This study provides theoretical and technical support for the development of integrated thermal insulation and load-bearing wall materials suitable for severely cold regions.
本研究基于物理发泡法，开发了一种以煤矸石和矿渣为前驱体、以硅酸钠和氢氧化钠组成的复合碱激发剂制备的新型地质聚合物泡沫混凝土。采用响应面法中的Box-Behnken设计对煤矸石-矿渣基地质聚合物泡沫混凝土的配合比进行优化。系统研究了碱激发剂用量、硅酸钠模数、水胶比和泡沫含量对28天抗压强度和导热系数的影响，以确定在力学性能和热性能之间取得平衡的最佳配合比。利用扫描电子显微镜和其他表征技术分析微观结构特征。结果表明，泡沫含量对力学性能和热性能的影响最为显著，而硅酸钠模数与泡沫含量之间的相互作用表现出最明显的综合效应。优化后的配合比设计为：碱激发剂用量9.1%、硅酸钠模数1.07、水胶比0.44、泡沫含量50%，28天抗压强度为2.30MPa，导热系数为0.0781W/(m·K)。观察到的性能提升主要归因于孔隙结构中不均匀性的增加。本研究为严寒地区保温承重一体化墙体材料的开发提供了理论和技术支持。
