Accelerated Bridge Construction (ABC) has been widely used as a means to reduce the number of structurally deficient or functionally obsolete bridges in the nation. This approach is important to state DOTs because of the number of structurally deficient bridges in the nation. To complement ABC construction, which largely uses prefabricated components, concrete barriers should also follow accelerated construction method so that bridges can be completed over as short of a duration as possible and back open to the public as quickly as possible. Use of cast-in-place construction of barriers on ABC bridges is time consuming and not cost effective. Therefore, new ways to use prefabricated products for barrier construction should be investigated. Following the evaluation of the current state of knowledge, Iowa State University researchers have developed precast concrete barriers that can be rapidly implemented. This initial research was funded by the Accelerated Bridge Construction-University Transportation Center (ABC-UTC) housed at Florida International University, who leads the ABC-UTC university consortium. The research project considered two different barriers to deck connection details that were designed and tested under quasi static loads to understand the load distribution and evaluate the connection performance. The first connection utilizing inclined reinforcing bars promotes durability and reparability but its initial cost is higher than the second alternative. The second connection that utilizes U-shaped reinforcing bars for connecting the precast barriers to the bridge deck is durable and cost effective, but replacement cost will be higher than the first alternative.

The purpose of this study is to develop an approved prefabricated barrier rail system for use on accelerated bridge construction (ABC) projects. It will make use of preliminary work completed by the ABC-UTC project (identification of structurally feasible system) and complete the evaluation protocol including crash testing to insure compliance with current AASHTO LRFD Specifications and AASHTO MASH.

The scope of work outlined below in task form builds upon the results of the ABC-UTC research project noted above (to be noted for this proposed Pool Fund Plan as Phase I). It is noteworthy that there have been prior presentations/discussions with the AASHTO Subcommittee on Bridges and Structures (SCOBS T-04) and with the Transportation Research Board Subcommittee on ABC (the parent committee is AFF00) regarding the proposed work, and both groups support the need for the work and have endorsed the general scope of work outlined below. Task 1: Review of ABC-UTC Project (Phase I) and Finalize Details (with limited brainstorming/R&D for multiple concepts) Task 2: Conduct Numerical Modeling and LS-DYNA Simulation Task 3: Perform Impact Tests on Selected Prototype Designs Task 4: Refinement of Designs and Calibration of Models and Determination of Critical Impact Points based on Outcomes from Task 3 Task 5a: Perform Full-Scale Crash Tests on Concrete Barrier-Deck System(s) based upon AASHTO MASH criteria Task 5b: Construct, Repair and Remove Full-Size Bridge and Rail Systems Task 6: Calibrate Numerical Models Task 7: Perform Parametric Study and Design Optimization Task 8: Develop Design, Construction and Implementation Guidelines Task 9: Conduct Life-Cycle Performance and Cost Analysis

Each partner’s commitment should total $20,000 per year for three years. Additional tasks have been deferred pending availability of funding/partners.