Study On Mechanical Properties On New Reconstituted Bamboo-Concrete Composite Bridge Deck

At present,steel structure and steel and concrete composite structureare widely used in domestic and international bridge.But with the continuous development of society and economy,the traditional reinforced concrete structure gradually exposed its inherent flaws,and one of the biggest problems is that the building material is not environmentally friendly,and does not meet the requirements of sustainable development.Therefore it is a feasible way for the sustainable development of modern construction industry to replace the concrete with natural renewable organic materials.Bamboo is a kind of natural renewable organic material,and our country is rich in bamboo resources.Compared with wood,bamboo has higher stiffness and strength,which makes it a good engineering structural material and have broad application prospects in the field of construction.Among the bamboo products,the reconstituted bamboois a kind of biomass composite material,which is made up by the original bamboo,which is cut,softened,and then dried into the fiber bundle,then dried,sizing,forming and hot pressing.It has the advantages of high strength,light weight,environmental protection and so on which make it a new building material with great development potential.But because of the lack of adequate understanding of the performance of materials of reconstituted bamboo,it needs a large number of tests before engineering applicationto solve the problems of material strength,bearing capacity and stiffness of the design.The main research object of this paper is the reconstruction bamboo concrete composite bridge deck.The main work of this paper is in the mechanical properties of the material,the performance of the composite structure screw connector and the bamboo concrete composite structure,which is as follows:1)Experimental study on basic mechanical properties of reconstituted bambooThe basic mechanical properties of bamboo were studied,including tensile strength,compressive strength,flexural strength,shear strength and elastic modulus,and the loading process and failure mode were analyzed.At the same time,the unidirectional properties of the bamboo material were studied.The effects of fiber orientation on the mechanical properties were analyzed by compression and shear tests.2)Experimental study on the screw connection of the bamboo concrete composite structureThe performance of connections between recombinant bamboo and concrete is the key to connect the composite bridge deck as a whole piece.In this study,the influence factors of the shear force on the shear capacity of the structure were studied,and the formula for calculating the shear bearing capacity and shear stiffness of shear connectors is obtained.At the same time,the loading process and failure mode of the screw channel shear bond are analyzed.3)Analysis of flexural capacity of reconstituted bamboo concrete composite structureWith the bridge deck of the bridge as the application background,the experimental design and analysis of the reconstituted bamboo concrete composite bridge deck were make.According to the principle of equivalent curvature,the calculation method of flexural stiffness and deflection of composite structures is established,and the bearing capacity of the composite structure is studied and analyzed.4)Finite element simulation analysis of composite structure of reconstituted bamboo and concreteBy finite element analysis,the optimum size of the bamboo concrete composite structure is determined,and the results were compared with the calculated value and the actual test results.And the failure mechanism and the stress distribution under different loads are analyzed.