Full-scale testing of non-proprietary ultra-high performance concrete for deck bulb tee longitudinal field joints

Using deck bulb tee girders (DBTs) is one of the most popular and reliable solutions nowadays for accelerated bridge construction (ABC). DBTs usually require to be longitudinally connected on-site using robust materials such as ultra-high performance concrete (UHPC) for the field joints. The unparalleled mechanical properties of UHPC mixes have gained material popularity for ABC connections. However, the proprietary and relatively expensive nature of robust UHPC mixes pose some limitations, which motivated many researchers along with state departments of transportation to develop less expensive and non-proprietary UHPC mixes. The objective of this study is to leverage a readily developed non-proprietary UHPC mix, but using local materials available in the western United States, and to proof-test it in DBTs full-depth longitudinal field joints. An experimental investigation was conducted to test two full-scale specimens of a representative DBT top flange section with longitudinal field joints under static vertical loading. The specimens varied in the field joint material where one specimen used the developed non-proprietary UHPC and the other used a robust commercial UHPC mix. The structural behavior of both specimens was evaluated in terms of load and deflection capacities as well as the field joint performance. The results demonstrated that the developed non-proprietary UHPC mix can be efficiently used for longitudinal DBT field joints with comparable performance to proprietary UHPC joints.