纳米石墨粉对红黏土力学性质的影响

EFFECT OF NANO GRAPHITE POWDER ON MECHANICAL PROPERTIES OF RED CLAY

对添加了纳米石墨粉的红黏土以击实进行了重塑样制备,设计了不同掺量纳米石墨粉在红黏土最优含水率下的三轴固结不排水试验;通过应力-应变曲线,分析了不同掺量纳米石墨粉对红黏土力学性能的影响,得出了抗剪强度和抗剪强度指标的规律,并采用SEM微观手段对其改善机理进行了分析。试验结果表明:抗剪强度和黏聚力C随纳米石墨粉掺量的增加先增加后减小,内摩擦角φ基本保持不变,得出适量的纳米石墨粉对红黏土的力学性质有显著的提高,最优掺量在1%~2%之间。研究认为,纳米石墨粉红黏土呈现出的力学性质,与纳米石墨粉对红黏土孔隙结构的影响、纳米石墨粉对红黏土颗粒的黏附胶结密切相关。

This papter uses the compaction method for preparing the remolded red clay with the addition of nano graphite powder（ NGP）. It designs the consolidation and undrained triaxial experiment of different dosage of NGP under optimum water content of red clay. The effect of doped with different amount of nano graphite powder on mechanical properties of red clay is analyzed by adopting the method of stress and strain curve,which obtains the rules of shear strength and shear strength index. The improving mechanism is futher analyzed with SEM method. The experimental results show that： with the increase of NGP content,the shear strength and cohesion C increase firstly and then decrease, the internal friction angle φ remains basically unchanged. It can be observed that the appropriate amount of NGP has an significantly improvement on the mechanical properties of red clay. The best dosage is between 1% to 2%. The study suggests that the presenting mechanical properties of NGP-red clay isclosely related to the effect of the NGP on the pore structure of red clay and the particle adhesion and cementation.