BACKGROUND: Steel reinforced concrete barriers, even when using epoxy coated steel reinforcement, have experienced premature deterioration due to salt exposure resulting in reduced service life. One solution is to use noncorrosive reinforcing materials such as glass fiber reinforced polymer (GFRP) in lieu of traditional steel or steel-coated reinforcement. Research and limited application by state departments of transportation (DOTs) has demonstrated the viability of GFRP as an alternative construction material for bridge barriers.
Research is needed to develop nationally accepted design and repair requirements for use of GFRP in concrete bridge barriers. The research outcome should help highway agencies make more informed decisions regarding the type of bridge barriers used and selection of repair strategies.
OBJECTIVE: The objective of this research is to develop design requirements for (1) new GFRP reinforced concrete barriers and (2) repair of damaged barriers using GFRP. The new requirements shall be according to the American Association of State Highway Officials (AASHTO) Manual for Assessing Safety Hardware (MASH).
PHASE I: (1) Collect and review information on current domestic and international practices relevant to design, testing, and repair of concrete bridge barriers using GFRP. Identify barrier size, shape, materials, test levels, repair strategies, and other details. This information may be obtained from published and unpublished information, and public and private organizations involved in design, construction, repair, and testing of barriers, including existing surveys of state DOTs. (2) Evaluate the details of the GFRP barriers identified in Task 1 and identify potential barrier designs and repair details (e.g., geometry; deck connections; anchorage and internal continuity detailing, such as couplers and splicing details) that merit further evaluation in Phase II. (3) Propose a research plan, to be executed in Phase II, to achieve the project objective. At a minimum, the research plan shall include:
(a) A comprehensive evaluation of the potential barrier details identified in Task 2,
(b) Numerical modeling and MASH testing of potential barriers to validate the proposed repair requirements, methods, and strategies. Include the number of crash tests to be performed,
(c) Design examples to illustrate use of the proposed requirements, and
(d) A preliminary outline and table of contents for the draft language of the requirements for the design of new and repair of damaged barriers using GFRP reinforced concrete for consideration by AASHTO to incorporate the research results in the appropriate AASHTO specifications (hereafter called AASHTO Deliverable). Include an annotated description of each section and subsection along with the proposed level of details of each subsection (i.e., brief, moderate, or extensive).
(4) Prepare an interim report that documents the research performed in Tasks 1 through 3.
Note: The work proposed for Task 5 must be divided into subtasks, and proposers must describe in detail the work proposed in each subtask. Following review of the interim report by the NCHRP, the research team will be required to make a presentation to the project panel. Work on Phase II of the project will not begin until the interim report is approved and the Phase II work plan is authorized by the NCHRP. The decision on proceeding with Phase II will be based on the contractor’s documented justification of the updated work plan.
PHASE II: (5) Execute the proposed research plan according to the approved Phase I interim report. (6) Develop the AASHTO Deliverable. (7) Prepare an interim report that documents the research performed in Task 5. Following review of the interim report by the NCHRP, the research team will be required to make a presentation to the project panel. Work on Phase III of the project will not begin until the interim report is approved and the Phase III work plan is authorized by the NCHRP. The decision on proceeding with Phase III will be based on the contractor’s documented justification of the updated work plan.
PHASE III: (8) Revise the AASHTO Deliverable after consideration of the panel’s review comments. (9) Prepare the design examples to illustrate use of the AASHTO Deliverable. (10) Submit the final deliverables including: (1) a final report that documents the entire research effort, (2) the AASHTO Deliverable, (3) a stand-alone technical memorandum titled “Implementation of Research Findings and Products” to facilitate implementation of the developed requirements, and (4) design examples.
STATUS: Research in progress.
