聚氨酯聚合物/剑麻纤维改良砂土剪切特性研究

Study on shear characteristics of sand reinforced by polyurethane/sisal fiber

为研究聚氨酯聚合物-剑麻纤维-砂土复合材料的剪切特性,本文采用直剪试验分别研究了砂土密度、剑麻纤维含量以及聚氨酯聚合物含量三种条件对于砂土复合材料剪切特性的影响。试验结果表明:砂土复合材料的剪切性能随着砂土密度的增大而增大;随着剑麻纤维含量的逐渐增大,各聚氨酯聚合物含量的砂土的剪切性能总体上先增大后减小;2%3%的聚氨酯聚合物加固砂土的效果最优。聚氨酯聚合物和剑麻纤维与砂土混合后,松散的砂土受到物理和化学的共同作用,其中聚氨酯聚合物在砂粒之间形成的固化膜使得砂土连接成为一体,且剑麻纤维的加筋作用,在土体内部形成三维空间结构,从而最终使得复合材料具有良好的抗剪强度特性。

In order to study the shear properties of polyurethane polymer sisal fiber sand composite,the effects of sand density,sisal fiber content and polyurethane polymer content on the shear properties of sand composite were studied by direct shear test.The results show that:the shear properties of sand composite materials will increase with the increase of sand density;with the gradual increase of sisal fiber content,the shear properties of sand with polyurethane polymer content increase first and then decrease;the effect of 2%3%polyurethane polymer on sand soil reinforcement is the best.The loose sand particles were subjected to a combination of physical and chemical stabilization after sand mixed with polyurethane polymer and sisal fiber.The polymer membrane which forms among sand particles could connect sand into a whole,and fiber plays a role of reinforcement forming a three-dimensional space structure,therefore the shear properties of composite material were significantly enhanced.