About the research
The objective of this project is to evaluate the performance of a second-generation accelerated bridge construction (ABC) bridge that utilizes two types of continuity connections: the transverse joint at pier diaphragms and the longitudinal joint between precast superstructure/deck units.
The bridge replacement project located on IA 92 over Little Silver Creek in Pottawattamie County, Iowa was used to demonstrate a second-generation ABC technique that had been previously used in Iowa. As a part of the holistic evaluation, the performance of an ultra-high performance concrete (UHPC) longitudinal joint detail and a high-performance material (HPM) transverse joint detail were studied through laboratory testing and numerical simulations. Additionally, field testing was conducted to evaluate the in-place integrity of the bridge.
The goals of this project are to demonstrate the performance and benefits of the ABC techniques using prefabricated bridge elements and systems (PBES) and HPMs and to contribute toward increased adoption of the technologies by Iowa and other states.
Through this project, the Iowa DOT gained valuable insights into the innovative ABC techniques used. The following were some of the lessons learned:
- UHPC is an excellent material for longitudinal closure pour connections.
- There may not be a need to use a compression block for the beam-to-beam transverse closure pours on a similar ABC project in the future.
- The UHPC longitudinal joints and the HPC transverse joints at the pier location are sufficient for the modular bridge systems of ABC projects.