减摩擦垫层对混凝土轴压试验的影响

Effect of Friction-reducing Padson Concrete Under Compression

聚四氟乙烯(PTFE)是一种低摩擦耐摩材料,在混凝土受压试验中被作为一种良好的减摩材料,但针对PTFE材料对混凝土力学特性影响的研究较少。本文采用100×100×100mm混凝土试块,结合试验装置加载板能否转动,研究PTFE层数及黄油对混凝土试块应力-应变曲线、峰值应力、峰值应力对应应变以及偏心的影响。研究发现:2层0.05mm厚PTFE接近最佳的减摩效果,且在竖向荷载达到60%的极限荷载(不加减摩层)以后PTFE的减摩效果明显,底部球铰可以有效地减小混凝土试块的偏心。试验结果为混凝土单轴及多轴试验提供了参考依据。

Polytetrafluoroethene（PTFE）is widely used as the friction-reducing material because of its low coefficient of friction and good abrasion resistance.However,there are few studies of the reduction effect of PTFE on the mechanical behavior of concrete.100×100×100mm normal strength concrete cubes were adopted for uniaxial compression test.Together with the condition of loading plate,the change of PTFE layer number and the grease were considered in the test.The qualitative study had been conducted to the effect on the stress-strain curve,peak stress,the corresponding axial strain and the additional eccentricity.The results show that 2layers of PTFE exhibit the best result in friction-reducing for concrete cube.PTFE functions become obvious when the axial load exceeds 60 percent of the peak load（the load of cube without frictionreducing pad）.The bottom spherical hinge can reduce the eccentricity effectively.These results are of reference for uniaxial and multi-axial tests of concrete.