Evaluation of Ultra-High-Performance Concrete for Use in Bridge Connections and Repair

Abstract

The project described in this report evaluated available proprietary ultra-high performance concrete (UHPC) materials and UHPC mix designs made with local materials for applicability to bridge joint installation and repair in Oklahoma and developed recommendations for continued usage of UHPC in bridge construction in Oklahoma. Phase 1 of the project developed a promising UHPC mix design, J3, using local materials. Two specific applications of UHPC were considered: deck slab joints and girder continuity connections. Initial investigation of deck slab joint details was conducted using small-scale flexural specimens to evaluate bond strength between UHPC and base concrete. Laboratory-scale full-depth joints were cast and tested using both the proprietary UHPC material and the OU developed J3 mix design. Laboratory-scale UHPC connections for live load continuity between precast girders were also designed and tested to failure. Two different connection details were used, one representing new construction and one representing retrofit of an existing structure. Afield test involving retrofit of an existing expansion joint with UHPC joint headers was conducted on a bridge identified in conjunction with ODOT and was monitored for almost three years. Phase 2 involved slab testing for a partial depth slab joint detail, examination of reinforcement bond, and durability testing of both proprietary and non-proprietary UHPC. UHPC bond to concrete substrate was also examined for different surface preparations and base concrete saturation levels. The findings of the research indicate that UHPC provides improved performance relative to conventional materials for the applications tested and the J3 mix design exhibits similar performance to proprietary UHPC.