More Choices for Connecting Prefabricated Bridge Elements and Systems (PBES)

Link to Latest Report:  September 2019 Progress Report

Background:
Prefabricating bridge elements and systems (PBES) offers major time savings, cost savings, safety advantages, and convenience for travelers. According to the FHWA, the use of PBES is also solving many constructability challenges while revolutionizing bridge construction in the US. In the past decade, innovative PBES connections have been evolved and many of these connections used Ultra-High performance concrete (UHPC). UHPC has superior mechanical properties and durability. However, some of the limitations associated with UHPC wide spread use include: the very expensive price tag, the expertise needed to work with UHPC, it is labor intensive, and most of the robust mixes are currently proprietary. Several DOTs see the proprietary nature of UHPC leads sometimes to sole-sourcing and in turn, bidding issues. Thus, there is a growing interest nowadays to find other alternatives and choices for PBES connections. The goal of this project is to identify potential alternatives to replace UHPC in PBES and ABC seismic and non-seismic connections. These alternatives can include special or advanced grout, polymer concrete, fiber concrete, etc. One selected material or alternative will be tested for at least two different PBES or ABC connection types.

Objective:
The research objectives of this study are: (1) collect and select potential alternative materials (e.g. polymer concrete) to replace UHPC in PBES connections; (2) characterize the material and mechanical properties of selected alternatives; (3) conduct large-scale testing to study the response of the alternative materials as used in structural ABC applications (mainly for joining deck panels as an implementation case study).

Scope:
An experimental approach will be used and several research activities will be executed to accomplish the objectives of this study. A summary of the proposed research tasks is as follows:

  • Task 1 – Literature search and selection of UHPC alternatives for ABC connections:  Several materials that have the potential to use for ABC connections such as Polymer concrete will be searched for applicability.
  • Task 2 – Material and mechanical characterization tests:  Material and mechanical characterization tests to characterize the properties of the identified material/s such as direct tension strength; compression strength; and modulus of rupture.
  • Task 3 – Development of experimental program and specimens design:  One application to test the new material alternative for ABC connections is deck joints. A large-scale testing program will be developed.
  • Task 4 – Experimental testing of deck slabs joints specimens:  Experimental testing of deck slabs joints specimens under different loading types (monotonic and cyclic vertical loading) will be conducted at the structures laboratory at UNR.
  • Task 5 – Final Report:  Summarize the results in a final report, which will be reviewed by the ABC-UTC steering committee then made available for dissemination.

Research Team:
Principal Investigator:  Dr. Mohamed Moustafa (UNR); Dr. Ahmad Itani (UNR)
Research Assistant:  Mohamed Abokifa

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