Expermental Study On Static And Dynamic Characteristics Of Granulated Rubber-Sand Mixture

With the development of automobile industry in recent years,the use of automobiles was increasing gradually and the number of disused tires was increasing day by day.Under filed conditions,waste tires were difficult to be degraded,which posed a great challenge to environmental protection.The application of granulated rubber-sand mixture in subgrade filling not only achieved the purpose of effective utilization of waste tires,but also improved the uneven settlement of subgrade.In this paper,treated granular rubber and sand were used and a series of unit tests were carried out to study the compression characteristics,shear characteristics,permanent strain and resilient modulus under cyclic loading.Based on the test results,the optimum mixing ratio was proposed,which could provide reference for practical engineering application.Specific research contents and results were as follows:(1)The compression characteristics of rubber-sand mixture under different loading sequences were studied.It was found that approximate ninety percent of plastic deformation of rubber-sand mixture was completed during the first and second loading-unloading process,while the elastic deformation had no obvious change during the loading-unloading process and kept constant.The development of elastic and plastic deformation in the loading-unloading process was revealed.(2)Through direct shear test and triaxial drained shear test,the shear characteristics of rubber-sand mixture with different content of rubber were studied.It was found that the shear strength gradually decreased with the increase of content of rubber.In the aspect of the various of volume,it gradually transited from dilatancy to shrinkage,which indicated that rubber could effectively inhibit the dilatancy behavior of the mixture.(3)A series of cyclic triaxial tests under drainage condition was carried out to study the development of strain and modulus.Compared with the traditional subgrade filler in terms of friction angle,permanent strain,resilient modulus and strain energy density,it was found that the rubbersand mixture with rubber content of 10% could meet the requirements of subgrade filler.