橡胶粉对聚丙烯纤维混凝土力学性能和微观结构的影响

Effect of Rubber Powder on Mechanical Properties and Microstructure of Polypropylene Fiber Reinforced Concrete

摘要:

为研究橡胶粉对聚丙烯纤维混凝土（PFC）力学性能和微观结构的影响,通过轴心抗压试验、自由衰减振动试验和扫描电子显微镜（SEM）,对比了PFC抗压强度、泊松比、弹性模量、阻尼比等性能指标,分析了橡胶粉对PFC界面以及微观形貌的影响.结果表明：随着橡胶粉的掺入,PFC抗压强度降低,峰值应变增大,弹性模量减小,棱柱体轴心抗压强度与立方体抗压强度的平均比值为090;弹性阶段PFC泊松比介于018～022之间;橡胶粉的掺入提高了PFC的阻尼性能,且在聚丙烯纤维掺量为15%时提高最显著;橡胶粉的填充行为和本身的黏弹性行为，可以改善PFC内部孔隙结构,提高骨料界面之间的摩擦损耗,能有效提高PFC的阻尼性能.

Abstract:

The effect of rubber powder on the mechanical properties and microstructure of polypropylene fiber concrete(PFC) was studied. Through the axial compression test and the free decay vibration test, the measured indexes of compressive strength, Poissons ratio, elastic modulus and damping ratio were compared. The effect of rubber powder on the microstructure and interface of polypropylene fiber reinforced concrete was investigated by scanning electron microscopy(SEM). The results show that with the addition of rubber powder, the compressive strength of the cube and prism specimen decreases, and peak strain increases. The average ratio of the compressive strength of the prism to its cubic compressive strength is 090. The Poisson ratio is between 018 and 022 in the elastic phase. The modulus of elasticity decreases. With the incorporation of rubber powder, the damping ratio of polypropylene fiber concrete is increased, and the most significant increase is achieved when the polypropylene fiber content is 15%. The filling behavior of the rubber powder and its own viscoelastic behavior can improve the internal pore structure of the concrete, and improve the friction loss between the aggregate interfaces, and effectively improve the damping performance of the concrete.