Study On Mechanical Properties Of Bamboo Fiber Reinforced Concrete Sleeper

Railway is the artery of China’s transportation,and the number of sleepers required for tens of thousands of kilometers of railway is huge.Traditional timber sleepers,cement sleepers and reinforced concrete sleepers in China have their own shortcomings.Bamboo and bamboo cellulose have a series of advantages,such as rich resources,short growth cycle,excellent mechanical and physical properties,environmental protection and so on.Bamboo fiber concrete is a kind of concrete,in which adding bamboo fiber to the mixture can enhance the overall mechanical properties of the composite structure.Bamboo fiber can increase the plasticity of concrete to a certain extent,thus improving its tensile properties and brittleness.In this paper,the mechanical properties of bamboo fiber reinforced concrete sleepers are studied:(1)Through the compression and tensile tests of bamboo fiber reinforced concrete cubes,the results of different volumes of bamboo fiber reinforced concrete blocks are co MPared.It is found that adding bamboo fiber into the concrete blocks will increase the compressive strength of the blocks,so 2% of bamboo fiber reinforced concrete has the greatest resistance in these compressive and tensile strengths.(2)Through three-point bending test,the bending performance analysis of bamboo fiber concrete sleeper based on DIC is studied.It is considered that attention should be paid to the structural design of bamboo fiber concrete sleeper.The structural design has a great influence on the bearing capacity of bamboo fiber concrete sleeper.At the same time,when the fiber volume fraction is more than 2%,the mixing of bamboo fiber and concrete is more uniform.It is suggested that the design of bamboo fiber concrete sleeper should be improved in engineering the volume fraction of the fiber in the medium is set at more than 2%.From the crack DIC results,it is suggested that bamboo fiber volume fraction should be set at 3%.(3)Take bamboo fiber concrete as the research object,use the finite element software ABAQUS analysis of its mechanical properties,mainly on the mechanical properties of bamboo fiber reinforced concrete materials and sleepers,first studied the classification of ballasted track and existing track,the mechanism and classification of bamboo fiber reinforced concrete materials,and then carried out the tensile and compression tests of bamboo fiber reinforced concrete materials,combined with the results of numerical analysis,obtained the volume of bamboo fiber and its overall force The best volume content of fiber is 2% under tension and compression condition,and 1% under three-point bending condition.The constitutive model and numerical model of fiber reinforced concrete are studied.(4)In the case of bamboo fiber volume content of 1%,the bearing capacity of each component of fiber reinforced concrete sleeper with the increase of pressure is studied.As the result shows,with the increase of the external load,the compression zone and its boundary move up gradually until the ultimate load is reached.The tensile stress is mainly borne by the internal reinforcement,and the concrete basically does not bear the tensile stress.Finally,combined with the research situation,the paper puts forward some prospects for the development of bamboo fiber reinforced concrete sleepers,and thinks that more detailed research should be carried out on the mechanical model and durability of bamboo fiber reinforced concrete.