3D Printed Concrete Interlayer Bonding Performance And Stability Analysis Of Printed Arch Structure

3D printed concrete technology is a new type of 3D printed construction technology that combines 3D printed technology with concrete construction technology.Domestic and foreign studies have shown that the interlayer bonding properties of 3D printed concrete have a significant impact on the mechanical properties of the 3D printed structure,and the current research on the interlayer bonding properties of 3D printed concrete is still in the preliminary exploration stage,and many factors are affecting the 3D printed concrete interlayer bonding performance.In this paper,the experiments and numerical simulation methods for the interlayer bonding properties of 3D printed concrete are studied,and the stability performance analysis of the 3D printed concrete arch structure is carried out.The specific research contents are as follows:(1)Designed and printed three 3D printed concrete double shear test specimens and two 3D printed concrete tensile performance test specimens,conducted 3D printed concrete specimen double shear tests and axial tensile tests,and obtained 3D printed failure modes,ultimate bearing capacity and load-displacement curve of concrete double-shear specimens and axial tensile specimens.The test results show that the interface between layers is a weak area of 3D printed concrete.The doubleshear test results show that as the load increases,the stiffness of the specimen basically remains unchanged until the brittle shear of the interlayer interface;the axial tensile test results show that with the increase of the load,the stiffness of the specimen basically remains unchanged until the brittle fracture of the interlayer interface.(2)Compare and determine the simulation method of 3D printed concrete interlayer bonding performance.Cohesive bonding unit was used to simulate the 3D printed concrete interlayer tensile performance and shear performance.The simulation results are in good agreement with the test results.The design and printing of six 3D printed concrete axial compression performance test specimens were completed,and the 3D printed concrete specimen vertical compression layer axial compression and co-bonding layer axial compression tests were performed to obtain the 3D printed concrete vertical bonding layer.The ultimate bearing capacity of compressive and co-bonded layers and the corresponding load-displacement curve.The test results show that the compressive strength of the 3D printed concrete test block along the cohesive layer is higher than that of the vertical adhesive layer.Finite element simulation was carried out on the axial compression performance test of the 3D printed concrete test block,and the simulation results were in good agreement with the test results,proving the effectiveness of the simulation method.(3)According to the stability analysis of 3D printed concrete arch structures with six different printed methods,the stability analysis of the 3D printed concrete arch structure was carried out systematically.Based on the simulation results,the ultimate bearing capacity and failure mode of the structure formed by different printed methods under vertical uniform load are analyzed,which provides suggestions for the engineering application of the 3D printed concrete arch structure.(4)The calculation formula of the ultimate bearing capacity of 3D printed concrete arch structures under different printed methods under vertical uniform load is proposed.The calculation formula considers different interlayer forms and the effect of the interlayer bonding strength on the ultimate bearing capacity of the structure and takes the ultimate bearing capacity into consideration.The calculated force value is compared with the numerical simulation result to verify the applicability of the calculation formula.