Zhan Jianghuai, Li Hongbo, Pan Qun, Cheng Zhenyun, Li Huang, Fu Bo
College of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China.
Chongqing Construction Science and Research Institute Co., Ltd., Chongqing 400060, China.
Materials (Basel). 2022 Apr 18;15(8):2944. doi: 10.3390/ma15082944.
Metakaolin-based geopolymers possess excellent corrosion and high-temperature resistance, which are advantageous compared to ordinary Portland cement. The addition of slag in metakaolin-based geopolymers is a promising approach to improve their mechanical properties. Thus, this study investigated the effect of slag content on the strength and shrinkage properties of metakaolin-based geopolymers. Increasing the slag content and NaO content was beneficial to the reaction of alkali-activated metakaolin-based geopolymers, thereby improving their compressive strength and density. After 56 days of aging, a maximum compressive strength of 86.1 MPa was achieved for a metakaolin-based geopolymer with a slag content of 50 mass%. When the NaO content was 12%, the compressive strength of the metakaolin geopolymers with a slag content of 30% was 42.36% higher than those with a NaO content of 8%. However, as the slag and alkali contents increased, the reaction rate of the metakaolin-based geopolymers increased, which significantly decreased the porosity, increased the shrinkage, and decreased the volumetric stability of the system. In this paper, in-depth study of the volume stability of alkali-activated metakaolin-based geopolymers plays an important role in further understanding, controlling, and utilizing the deformation behavior of geopolymers.
偏高岭土基地质聚合物具有优异的耐腐蚀性和耐高温性，与普通硅酸盐水泥相比具有优势。在偏高岭土基地质聚合物中添加矿渣是提高其力学性能的一种有前景的方法。因此，本研究调查了矿渣含量对偏高岭土基地质聚合物强度和收缩性能的影响。增加矿渣含量和NaO含量有利于碱激活偏高岭土基地质聚合物的反应，从而提高其抗压强度和密度。经过56天的老化，矿渣含量为50质量%的偏高岭土基地质聚合物的最大抗压强度达到86.1MPa。当NaO含量为12%时，矿渣含量为30%的偏高岭土聚合物的抗压强度比NaO含量为8%的高出42.36%。然而，随着矿渣和碱含量的增加，偏高岭土基地质聚合物的反应速率增加，这显著降低了孔隙率，增加了收缩率，并降低了体系的体积稳定性。本文对碱激活偏高岭土基地质聚合物体积稳定性的深入研究，对进一步理解、控制和利用地质聚合物的变形行为具有重要作用。
