Finite-element modeling of UHPC hybrid bridge deck connections

In recent years, linked bridge deck elements have gained popularity for facilitating more durable components in bridge decks, but these components require field-applied connections for constructing the entire bridge. Ultra-high-performance concrete (UHPC) is started to be a major material for closure pours in bridges and various Department of Transportations have been developing guidelines. UHPC is known by its superior quality than conventional concrete in terms of constructability, strength and durability. So far, very limited data are available on the finite-element modeling (FEM) of hybrid bridge deck connections. In this study, FEMs have been presented to define the crucial factors affecting the response of bridge hybrid deck panel system under monotonic loads. The commercial software ABAQUS was used to validate the modes and to generate the data presented herein and the concrete damage plasticity was used to simulate both conventional concrete and UHPC. Numerical results were validated using available experimental data. The key parameters studied were the mesh size, the dilation angle, reinforcement type, concrete models, steel properties, and the contact behavior between the UHPC and the conventional concrete. The models were found to capture the load–deflection response of experimental results, failure modes, crack patterns and ductility indices show satisfactorily response. A sensitivity test was also conducted by considering various key parameters such as concrete and steel constitutive models and their associated parameters, mesh size, and contact behavior. It is perceived that increasing the dilation angle leads to an increase in the initial stiffness of the model. The damage in concrete under monotonic loading is found higher in normal concrete than UHPC with no signs of de-bonding between the two materials. Changing the dilation angle from 20° to 40° results in an increase of 7.81% in ultimate load for the panel with straight reinforcing bars, whereas for the panel with headed bars, the increase in ultimate load was found 8.56%.