Study On Mechanical Properties Of Waste Tire Soil Composite

A lot of old tires have been produced with the rapid development of the automobile industry.According to the survey,in 2012,the number of china's tire production is about 892 million,resulting in the number of waste tires is 280 million,with a total weight of 10 million 180 thousand tons,ranking first in the world.The"black pollution" caused by old tires is becoming more and more serious,which is harmful to the natural environment and human health.To solve the above problems,this project puts forward the innovation model of tire-soil retaining wall,the waste tires is used to be the material of the retaining structure,which can avoid the two processing of abandoned old tires and reduce the cost and environmental pollution.The principle of the technique is that the soil or recycled aggregate is filled into the waste tire and compacted to form a tire soil complex,and then layered and superimposed to form a gravity retaining wall.From the stress mechanism of the composite,the tire will be compressed into the tire cavity to form a stable complex because of its solid and high cycle force.In this paper,the feasibility of using waste tire as retaining wall material in engineering construction is studied.Including:the structure and mechanical property of waste tires,a waste tire soil complex monomer indoor compression test,waste tire soil complex shear test,complex numerical analysis.The main work and achievements of this paper are as follows:(1)This paper analyzes several main waste tire recycling advantages and disadvantages,and evaluate the effects of scrap tire of this material on the environment,focusing on the waste tires as the geotechnical materials for several main forms and methods of Engineering construction.(2)The composition and structure of waste tires are analyzed,and laboratory tests are carried out to test their mechanical properties.The feasibility of using waste tires as geotechnical materials is proved.(3)the unconfined compression test and resilient modulus test were carried out on the stress and deformation characteristics of the waste tire soil composite.The results show that:?the deformation modulus of the composite is related to the particle size of the filling material;under the same compactness,the smaller the deformation modulus is,the larger the particle size is,and the larger the proportion of the increase of the density after unloading.At the same time,the deformation modulus is also positively related to the compactness of the filling material.?The vertical stress-strain relation curve of the tire soil complex is first convex and then concave.The reason is that the front of the convex deformation is due to pre pressure,filling the gap has been part of the dense;the back end of the concave deformation is because as the load increases,the gap has become more difficult to be dense.?The trend of vertical stress radial strain curve of tire soil composite is pre convex and then concave,and the reason is the same as that of vertical stress vertical strain.?After unloading,the composite can not rebound to the origin,indicating that the composite has both elastic deformation and plastic deformation.?The value of deformation modulus of composite is discussed,and the relationship between compound deformation modulus and tire elastic modulus and filling material elastic modulus is obtained.(4)the tire soil complex was simulated by numerical software ansys.The results show that:?From data of the numerical simulation software,when the waste tire-soil composite structure used in civil engineering,the influence of the external constraints of tire can heighten soil compressive modulus,decrease lateral deformation,reduce settlement and increase the stability of slope effect.?By comparing the numerical simulation data with the experimental data,the results of the two are in line with each other,indicating that the experimental methods and test steps are scientific.In engineering practice,the finite element model can be used to simulate the actual working conditions to reduce the workload of the test.(5)study on the interface characteristics of waste tire soil composite.The results show that:the interface between the tire and soil composite can improve the shear effect,mainly by increasing the internal friction angle of the soil,and the cohesion will decrease.Due to the weight of the tire side wall has a concave and soil,so the complex between the final shear failure surface does not appear in the center line of contact two tires,but appeared in the above on the side of the tire,showing a convex curve,and tend to stress the end.Thirdly,the shear test of composite is carried out,and the main factor affecting the shear strength of composite interface is the strength of backfill soil.