纳米石墨粉掺入对红黏土微观结构的影响
Effect of Addition of Nano-Graphite Powder on Microstructure of Red Clay

纳米石墨粉是一种具有良好应用潜力的土体外掺剂，可以运用于红黏土的性质改良中。本研究对采自桂林两地红黏土的矿物成分进行分析，并对原状样品与纳米石墨粉改性后样品进行微观成像观察，探究了纳米石墨粉对红黏土微观结构的影响。结果显示：雁山、杨堤两地红黏土主要矿物成分为高岭石、石英、埃洛石和三水铝石，两地红黏土均有较强的淋滤、风化程度，其中雁山红黏土的淋滤、风化程度均强于杨堤红黏土。纳米石墨粉的掺入有效地改善了红黏土的微观结构，缩小了其孔隙尺寸，增强了其土体结构的整体胶结性，使其向均匀的密实结构变化。雁山、杨堤两地原始未压缩样品在1%~2%掺量比时可呈现出最为致密的土黏结构，而压缩样品的土黏结构均于2%掺量比时达到最为致密的状态。
Nano-graphite powder is a kind of in vitro soil admixture with good application potential, which can be used in the property improvement of red clay. In this study, the mineral composition of the red clay in Guilin, and the micro-morphology of the original samples and the modified samples were observed, so as to explore the influence of the nano-graphite powder on the microstructure of the red clay. The results show that the main mineral components of Yanshan and Yangdi red clay are kaolinite, quartz, halloite and bauxite. The red clay of Yanshan and Yangdi have strong leaching and weathering degrees, among which the leaching and weathering degrees of Yanshan red clay are stronger than those of Yangdi red clay. The addition of nano-graphite powder effectively improved the microstructure of the red clay, reduced the pore size, enhanced the overall cementation of the soil structure, and made it change to a uniform compact structure. The original uncompressed samples from Yanshan and Yangdi showed the densest soil structure at 1%~2%, while the soil structure of the compressed samples reached the densest state at 2%.