Study On Poisson's Ratio Of Rubber-Sand Mixtures

Rubber-sand is a kind of packing by mixing up the waste tire wear particles and sand.It has excellent characteristics to meet the requirements of civil engineering,and can deal with the increasing solid wastes such as waste tires,for which it has broad application prospects.But so far,there is few research on Poisson's ratio of this new material rubber-sand,which is far behind the need for the intended application and the theoretical analysis of the project.The study on the Poisson's ratio change of rubber-sand under different factors has been undertaken by static triaxial shear test.In this paper,the main contents and results are as follows:1.Rubber sand dry density tests have been carried out under different proportion,and the regression equation of the maximum and minimum dry density of rubber-sand change over the rubber content rc has been obtained,which can provide the basic for selecting the test parameters in further research.2.The expression of Poisson's ratio has been calculated under the triaxial stress state based on Generalized Hooke theorem,and its rationality has been demonstrated.3.The influence of confining pressure on the ratio of rubber to Poisson's ratio have been studied.It was found that Poisson's ratio first decreases and then increases with the increase of the ratio at the same confining pressure,and for the dilatancy inhibitory of the rubber particles,properties of various rubber ratio Poisson's ratio is less than 0.5 in the whole strain range,and at the same ratio,the confining pressure have smaller effect on the Poisson ratio of rubber sand.4.The study on the influence of initial water content on the change of Poisson's ratio by testing 20% and 30% rubber sand in the low moisture range shows that: Poisson's ratio of 20% rubber sand has been less affected than 30% rubber sand by moisture,the Poisson's ratio-axial strain curve of 30% rubber sand increases with the water content increases.Two different laws of the impact of different moisture contents on rubber sand ratio reflects the influence mechanism of the effective mechanism of moisture.5.The effect of relative density on Poisson's ratio of three matching rubber sand under different initial conditions has been analysed: Poisson's ratio increases with the increase of initial relative density of rubber sand,but as the ratio increases,the effect of initial relative density of the sand rubber Poisson ratio decreases.