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Project Details
STATUS

Completed

START DATE

02/21/17

END DATE

06/30/18

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

National Academy of Sciences

Researchers
Principal Investigator
Başak Aldemir Bektaş

About the research

The objective of this research was to identify the main reasons for bridge decommissioning in the United States. Relevant studies from the literature reported deficiency, poor National Bridge Inventory (NBI) condition ratings, lower load-carrying capacities, vulnerabilities, and road widening projects as the most common causes of bridge decommissioning. A common finding in earlier studies was that the reasons for decommissioning could not be identified for a significant portion (15% to 30%) of the records.

For the first analysis in this research, decommissioned structures were identified from historic NBI files, and their characteristics were analyzed. Based on a national survey performed for the project, a literature review, and an initial analysis, potential drivers of decommissioning were identified. These potential drivers were then compared with agency reasons gathered from five States (Utah, Michigan, California, Pennsylvania, and Florida). The final task was a comparative analysis of the decommissioned structures with the new structures that replaced them.

Overall, functional improvements are the major driver of bridge decommissioning, and they also explain a majority of unexplained cases. Structures replaced for functional reasons are also replaced younger than the structures replaced due to poor condition on average. Although the potential drivers provide sufficient identifiers of decommissioning, drivers derived from the NBI data by themselves are not specific enough to explain decommissioning as comprehensively as agency-provided reasons.

Project Details
STATUS

In-Progress

START DATE

04/09/15

END DATE

04/08/17

RESEARCH CENTERS InTrans, CMAT
SPONSORS

American Association of State Highway and Transportation Officials (AASHTO)
National Academy of Sciences
National Cooperative Highway Research Program (NCHRP)

Researchers
Principal Investigator
Doug Gransberg
Co-Principal Investigator
Hyung Seok "David" Jeong

Affiliate Researcher

About the research

The objectives of this research are to (a) quantify the costs and benefits of a formal partnering process and (b) prepare a recommended AASHTO Partnering Handbook, Second Edition.

Visit the AASHTO Partnering Handbook, Second Edition project website at the Transportation Research Board for more information.

Project Details
STATUS

Completed

START DATE

04/13/09

END DATE

03/31/10

RESEARCH CENTERS InTrans, CP Tech Center, CTRE
SPONSORS

National Academy of Sciences

Researchers
Principal Investigator
Peter Taylor

Director, CP Tech Center

Co-Principal Investigator
Shashi Nambisan

Transportation Research Engineer

About the research

Increased concern for environment and worker safety requires that alternatives be found to avoid working with hazardous materials. An alternative for the calibration method using mercury in Section 4 of AASHTO T 153/ASTM C 204 is needed. The objective of this project was to add an alternative method to AASHTO T 153. The new method must not use hazardous materials and be safer to use than the current method while maintaining the accuracy and precision of the current method.

The researchers concluded that mechanical devices can be use to measure and calibrate Blaine cells with sufficient precision to allow users to conduct measurements without the need to handle mercury, and proposed changes to AASHTO Test Method T 153 to allow use of physical measurements. The report was forwarded to AASHTO staff to make it available to the chair and members of the AASHTO Highway Subcommittee on Materials, and to consider adoption of the recommended changes.

Project Details
STATUS

In-Progress

START DATE

12/15/06

END DATE

12/14/07

RESEARCH CENTERS InTrans, CTRE
SPONSORS

National Academy of Sciences

Researchers
Principal Investigator
Michael LaViolette

Bridge Engineer Specialist

About the research

The objectives are to review and discuss the state-of-the-practice of incremental launching of bridges around the world and to identify the critical issues for consideration in design and construction of bridges using incremental launching. A strategic plan for increasing the use of incremental launching in the U.S. will also be developed.

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