High-Performance Grout Materials and Applications for Full-Depth Precast Overhang Bridge Deck Panels

Construction of a full-depth concrete bridge deck overhang system requires the use of a high performance grout to provide a fully composite connection between the girder and full-depth precast panels. This is achieved by specifying a grout mix that has sufficient performance in both its fresh and hardened state. This paper assesses the performance of two types of grout that are recommended for this purpose: firstly a proprietary grout commonly used in structural applications, followed by an alternative grout mix design produced from conventional materials. Each grout mix is assessed based on individual standardized tests so that an optimum mix design can be selected based on the grout’s overall performance. The selected mixes are tested in an experimental ‘grout track’ designed to replicate on-site placement, through varying haunch heights. The proprietary grout provides a very fluid grout mixture without sacrificing performance in other areas. The conventional mix design show very similar performance results to that of the proprietary grout, thus presenting a viable low cost option. Due to variability in grout materials and batching, grout specifications should be defined on a performance basis accompanied with strict quality control testing on the fresh properties. The experimental ‘grout track’ proved to be a novel, yet effective solution to assess and simulate the required field performance of the grout mixture.