Investigation into the effect of calcium on the existence form of geopolymerized gel product of fly ash based geopolymers

作     者：Zhao, Xianhui Liu, Chunyuan Zuo, Liming Wang, Li Zhu, Qin Wang, Mengke 

作者机构：Hebei Univ Technol Sch Civil Engn & Transportat Tianjin 300401 Peoples R China Hebei Univ Engn Coll Civil Engn Handan 056038 Peoples R China Hydrol Engn Geol Survey Inst Hebei Prov Shijiazhuang 050021 Hebei Peoples R China 

出 版 物：《CEMENT & CONCRETE COMPOSITES》 (水泥与混凝土复合材料)

年 卷 期：2019年第103卷

页      面：279-292页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0814[工学-土木工程] 

基　　金：Science and Technology and Project Foundation of Heibei Province (China) [15273802D] National Natural Science Foundation of China 

主　　题：Calcium-containing geopolymer Class F fly ash Microstructure detection Geopolymerized gel product Calcium component Hydrochloric acid resistance 

摘      要：Fly ash-based geopolymer, regarded as a eco-friendly cementitious material instead of ordinary Portland cement, has been rapidly developed and applied in practical engineering practice. Previous researches demonstrated that calcium component produces distinct effect on the formation of polymer gel products, and therefore influencing the macroscopic mechanical behaviors and microstructure of geopolymers. However, the influence mechanism of calcium component on the formation of gels product is still not clear. In this study, different content of Ca (OH)(2) were adopted to prepare calcium containing geopolymers. The compressive strength and hydrochloric-acid attack tests were conducted to evaluate the effect of calcium content on the macro-performances. Then, scanning electron microscopy-energy spectrum test (SEM-EDS) was carried out to accesses the morphology and elemental components of the prepared composites. Thereafter, the microstructure of gels product was probed through Fourier transform infrared (FTIR) spectroscopy and Si-29 nuclear magnetic resonance (NMR) spectroscopy. The critical value of elemental ratio (Na + K + Ca)/Al to characterize the gel product was specified. Two kinds of fly ash and two alkali-activated solutions were adopted to verify the results. The geopolymerization products will be calcium-containing geopolymer gels (C,N-A-S-H) when (Na + K + Ca)/Al 0.95. The results provide experimental basis and references for the application of calcium-containing solid wastes in geopolymer materials.