Modeling the Shear Connection in Adjacent Box-Beam Bridges with Ultrahigh-Performance Concrete Joints. I: Model Calibration and Validation

Abstract

Recent research on ultrahigh-performance concrete (UHPC) for connection elements in highway bridges indicates an improvement in the performance of the overall bridge superstructure. However, there is limited information on the effect of the material and bond strength of the UHPC on the load transfer mechanism between adjacent box girders. A three-dimensional finite-element (FE) model was developed to study the interface between UHPC and high-strength concrete (HSC) highway bridge connections. The UHPC-HSC interface was modeled using traction-separation, damage initiation criteria, and damage evolution while taking into account adhesion, friction, and the nonlinear material behavior. Material properties were determined directly from laboratory testing, and the interface parameters were identified through model calibration using direct tension test results and friction coefficients reported in the previous work. The model was validated by simulating the laboratory tests conducted at the Federal Highway Administration (FHWA) Turner-Fairbank Highway Research Center (TFHRC), and good agreement between numerical and experimental results was obtained. Finally, numerical simulations of two adjacent box-girder models using the proposed interface parameters and other interface models from past research were compared, and the results highlight the importance of using a high-fidelity model to accurately represent the system behavior.