干燥及饱和橡胶砂压缩和剪切特性

Compressibility and shear properties of dry/saturated rubber sand

将废弃轮胎作为建筑材料应用在土木工程领域是对其回收处理最有前景的方法之一。为了研究轮胎橡胶颗粒改良砂土的效果,选取橡胶颗粒与福建砂的混合土为研究对象,研究了橡胶砂的压缩和抗剪特性,分析了橡胶含量与干湿状态对橡胶砂力学特性的影响,并建立了双曲线模型预测橡胶砂受剪过程的剪应力与剪切位移关系。结果表明:橡胶砂的压缩变形随橡胶含量增大而增大,饱和橡胶砂的压缩变形明显大于干燥橡胶砂;橡胶砂的剪应力剪切位移曲线表现出应变硬化特征;橡胶砂的抗剪强度与橡胶含量的关系不大;干燥试样内摩擦角随着橡胶含量的增大而降低,饱和试样的内摩擦角随着橡胶含量的增大而轻微升高;通过双曲线模型预测的剪应力剪切位移关系曲线与试验结果吻合。

The usage of scrap tires as construction materials in civil engineering is one of the most promising ways in recycling this troublesome waste material.In order to investigate the effect of adding granulated rubber in improving the performance of sand,the compressibility and shear properties of granulated rubber-Fujian sand mixtures was studied by confined compression tests and direct shear tests.The influence of rubber content and water content on the mechanical characteristics of rubber-sand mixtures were studied,and a hyperbolic model was established to predict the shear stress-strain relationship of rubber sand.The research findings are as follows:The compression deformation of rubber-sand mixtures increases with the rubber content,and the compression deformation of saturated mixtures is greater than that of the dry mixtures.The shear stress-horizontal displacement curve of rubber-sand mixtures shows a strain-hardening characteristic.There is no obvious relationship between shear strength and rubber content,and the pore water has great influence on internal friction angle of rubber sand.The internal friction angles of dry samples decrease with the increase of rubber content.The internal friction angles of saturated samples increase with the rubber content.The hyperbolic constitutive model can be used to predict the shear stress-displacement relationship of rubber sand.