| Constructing bridges in rural areas by using cast-in-place construction method can be particularly challenging. Using deck bulb tee (DBT) girders allow the State Transportation Departments to partially mitigate this challenge. DBT girder bridges offer the benefit of quick construction. This makes DBT girder projects appealing to the State Transportation Departments. This process involves casting each bridge girder and portion of the deck in precasting yard before transporting to the bridge site. Only adjacent deck elements require any type of connection. These connections can be achieved using steel inserts, grouted joints or fresh concrete. One such material is ultra-high performance concrete (UHPC). Fiber-reinforced UHPC offers improved compressive and tensile strengths. This reduces the necessary splice length and results in narrower pour. A proprietary UHPC has been widely used in the United States. This UPHC has been tested to have 20,000 psi or more of compressive strength. But, this strength comes with a cost. It is 20-30 times more expensive than standard concrete primarily because of labor and installation costs. To address these cost challenges, this project is proposing a new UHPC material that utilizes locally-sourced materials. This project hinges on three tasks being successfully completed. The first step focuses on investigating and optimizing the UHPC mix using materials available locally and domestically as an alternative to commercially available pre-packaged UHPC products. Second, an analysis of material’s mechanical properties is conducted. Using standard small specimens, the mechanical properties tested in this research are compressive and tensile strength, modulus of elasticity, shrinkage, and bond strength with precast concrete. In addition, large-scale panel bending tests were conducted to evaluate the overall strength of the non-proprietary UHPC in a closure pour between two precast components resembling connections between the deck portions of deck bulb tee girders and compare the results with the proprietary UHPC. Third, using the results of the larger specimens, a bridge with deck bulb tee girders is modeled in ANSYS. The behavior of the 8-in. closure pour connection with non-proprietary UHPC is examined under the AASHTO LRFD design requirements for Strength I and Service I Limit States. |