Li Jing, Yang Lang, Rao Feng, Tian Xiang
Zijin School of Geology and Mining, Fuzhou University, Fuzhou 350108, China.
School of Civil Engineering, Changsha University of Science and Technology, Changsha 410114, China.
Materials (Basel). 2022 Jun 30;15(13):4599. doi: 10.3390/ma15134599.
Geopolymers have attracted extensive attention in the marine environment because of its special reticulate nanostructure. Gel evolutions of copper tailing-based green geopolymers were studied under air, deionized water, seawater, freeze-thaw cycle and carbonization environments. Their mechanical properties and microstructures were characterized by compressive strength measurement, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). It was found that the deionized water and natural marine water exposure promoted the evolution degree of geopolymers and improved their compressive strength, while exposure to the carbonization environment weakened the gel evolution and decreased the cross-linking degree of the Sodium aluminosilicate hydrate (N-A-S-H)gel structure, resulting in a decline of compressive strength. The geopolymer exposed in the freeze-thaw cycle exhibited the worst deterioration due to the expansion caused by the crystallization in the geopolymer. These results are essential and beneficial to further understanding the gel formation process in various marine environments and could promote the investigation of green concrete.
地质聚合物因其特殊的网状纳米结构而在海洋环境中受到广泛关注。研究了基于铜尾矿的绿色地质聚合物在空气、去离子水、海水、冻融循环和碳化环境下的凝胶演化过程。通过抗压强度测量、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、核磁共振（NMR）和扫描电子显微镜（SEM）对其力学性能和微观结构进行了表征。结果发现，去离子水和天然海水暴露促进了地质聚合物的演化程度并提高了其抗压强度，而暴露于碳化环境会削弱凝胶演化并降低硅铝酸钠水合物（N-A-S-H）凝胶结构的交联度，导致抗压强度下降。由于地质聚合物中结晶引起的膨胀，经历冻融循环的地质聚合物表现出最严重的劣化。这些结果对于进一步理解各种海洋环境中的凝胶形成过程至关重要且有益，并可促进绿色混凝土的研究。
