Research On The Mechanical Behavior Of Segmental Precast Concrete Beams With Epoxied Joints

Segmental precast concrete bridges are characterized by rapid construction,higher standardization and less intervention on existing traffic system,so its engineering applications gradually increased.In comparison to monolithically cast structures,there are some uncertainties in terms of the connections between precast segments,these uncertainties limit the application of this sort of structures.Experiments on segmental precast concrete bridge with epoxied joints were conducted.The main work and conclusions are as follows:(1)Eight epoxied segmental precast concrete beams and three monolithically cast beams were tested.The failure phenomena,stresses and displacements were recorded in detail.The results showed that the test beams which applied prestress have brittle fracture characteristics,the test beams applied prestress have ductile failure characteristics.All cracks started from the bottom of the joint section or the plain concrete around the joint section at the bottom of the beams.(2)The effects of the factors including shear span ratio,normal stress level and the fabrication process on the mechanical behavior of the specimens were discussed.(3)The finite element analysis software "ABAQUS" was used to simulate the test beams,and the stress states of concrete near the joint section were analyzed in detail.The calculated results were in good agreement with the experiment.(4)Based on the analysis of the biaxial stress state and the principal tensile stress,a discussion on the law about the crack development and extension of the concrete beams with epoxied joints was undertaken.(5)The numerical simulation was carried out to assess the mechanical behavior of the precast segmental concrete beams.The parameters included different thickness of epoxy adhesive,different elastic modulus of the concrete around the joint,different bonded effection between segments,and the level of prestressing.(6)Based on the experimental study and numerical analysis results,some suggestions are suggested to ensure the quality of the precast segmental concrete stucture.