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GFRP Barrier Testing Evaluation and Repair Strategies

项目名称：	GFRP Barrier Testing Evaluation and Repair Strategies
摘要：	Deterioration of bridge decks and safety barriers in salt exposure conditions using traditional steel reinforced concrete, or even using epoxy coated steel, has demonstrated the inability of steel reinforcement to satisfy today’s desired 100-year service life due to the susceptibility of traditional steel reinforcement to galvanic corrosion. While the AASHTO Load and Resistance Factor Design Specifications do not specify a specific service life for bridges, more recent guides provide a path for selecting a target service life including life cycle cost analysis approaches. Other international standards such as the British Standards set a specific required 120-year service design life. One solution to address the long-term service life target of 100 years that many state departments of transportation (DOTs) desire in their bridge deck systems is to use noncorrosive reinforcing materials such as glass fiber reinforced polymer (GFRP) in lieu of traditional steel or steel-coated systems. Since the late 1990s and early 2000s, GFRP materials have been demonstrated in bridge elements, including bridge decks in both hybrid reinforced deck applications or more recently fully steel free GFRP reinforced decks. However, a few challenges in the 2000s and 2010s have slowed the widespread implementation of steel free GFRP usage into bridge deck systems. These are generally perceived as (1) AASHTO design standards developed for using these materials, (2) remaining concerns on the materials long-term durability, and (3) development of barrier systems along with physical crash testing and repair strategies for damaged barrier systems. In recent years, efforts have been made to address challenges one and two. Late in 2018, AASHTO produced the second edition of the GFRP Design Guide Specification (AASHTO, 2018). In addition, several states including Florida, Ohio, and Missouri, have initiated efforts to develop and standardize GFRP reinforced barriers. The first major effort to thoroughly investigate a significant number of GFRP reinforced concrete (RC) bridge decks after 15-20 years of service exposure has been completed, showing no signs of degradation in the reinforcing materials. In this investigation, 11 bridges situated mostly in aggressive northern climates were inspected, sampled, and studied in depth, including microstructure analysis. It appears that the remaining issue to a fully validated steel free deck system, including the bridge barrier, is to (1) develop repair strategies on the barrier configurations developed/under development by the aforementioned DOTs, (2) conduct full scale crash testing on undamaged GFRP RC barriers and repaired GFRP impact damaged barriers, and (3) benchmark the test results in objective 2 to currently available crash test data for traditional reinforced barriers. The objective of this project will be to build on existing research on GFRP RC barriers in crash testing and tested design repair strategies for impact damaged GFRP RC barriers to restore full crash test capacity to damaged GFRP RC barriers. The desire of the repair strategies is to examine anchorage and internal continuity detailing such as innovative couplers and splicing details. Major tasks could include the following: (1) A state DOT survey and literature review to collect all information on current DOT GFRP RC barrier systems along with any laboratory and field-testing undertaken to date. (2) A literature review to identify promising coupler and continuity devices that have demonstrated experimental results to develop full tensile capacity in discontinuous GFRP bars. These are to be considered in the repair strategies. (3) To design and evaluate GFRP RC barriers developed with repair strategies under finite element method (FEM) modelling and laboratory static and cyclic evaluation. (4) To compare existing data on baseline RC control barriers (w/steel and GFRP) to the same barriers that have incorporated the repair strategy in the prior task. (5) Undertake full scale crash testing and FEM modelling on undamaged GFRP RC barriers as well as damaged GFRP RC barriers that have undergone the repair strategy. MASH TL-4 impact conditions for initial testing and repair should consider static/dynamic component testing for investigations/verifications as required. Results from these field tests would be benchmarked to existing crash tested steel RC barriers of the same size and cross section.
状态：	Proposed
资金：	850000
资助组织：	National Cooperative Highway Research Program；American Association of State Highway and Transportation Officials (AASHTO)；Federal Highway Administration
项目负责人：	Hanna, Amir N
开始时间：	20220607
主题领域：	Highways；Materials；Safety and Human Factors