Project Statement 16-212

Form ProjStat (Rev. 5/2013)

(RTI) Research Project Statement 16-212

FY 2016 Annual Program

Title: Designing for Deck Stress over Precast Panels in Negative Moment Regions The Problem: The design and reinforcing of decks in negative moment regions when sub deck panels are used is not clearly defined in the AASHTO LRFD Bridge Design Specifications. This AASHTO specification provides no specific deck reinforcement guidance when the deck is on continuous prestressed concrete girders. When the deck is on continuous steel girders, the AASHTO specification requires 1% reinforcement (1% of the gross slab cross sectional area) in two mats (2/3 in the top) be used. From the commentary, the placement of reinforcement can be waived at the discretion of the Engineer when precast panels are used. The use of panels is strongly supported by the construction industry as they lead to cost savings and provide a safe working surface. Industry requests the use of panels now on straight steel bridges and on continuous prestressed concrete girders, which leads to panels being placed in negative moment regions. The lack of guidance tends to lead engineers into making too-conservative, often costly decisions on how to reinforce the deck in these regions, such as trying to reinforce for the tension in the deck, fitting the full 1% of reinforcement in just the top mat, or restricting the use of panels in the negative moment area. All of these solutions complicate the bridge plans and increase the construction time. In the case of continuous prestressed concrete, since there is no guidance, this could lead the engineer to decide that no additional reinforcement is needed. This would result in a deck that will have uncontrolled cracking and not perform well. Technical This research will provide guidance for designing for deck Objectives: stress over precast panels in negative moment regions. In order to successfully complete this project, the researchers will perform the following steps:

1. Survey existing continuous prestressed girder structures, and identify their cracking and original deck design. Exclude consideration of continuous for LL only systems.

2. Instrumentation, testing, and evaluation of in-situ decks on continuous prestressed concrete girders built with sub deck panels. Full-scale or near full-scale physical test models can be substituted for actual bridges if none are available.

3. Develop guidelines for the design and detailing of decks on continuous prestressed concrete girders constructed with sub deck panels.

Desired 1. Value of Research (VoR) that includes both Deliverables: qualitative and economic benefits.

Project Statement 16-212 Form ProjStat (Rev. 5/2013)

(RTI) 2. Research report summarizing the findings from the survey, detailing the research completed, summarizing the findings of the research and providing recommended guidelines.

Proposal 1. Proposals will be considered non-responsive and will not Requirements: be accepted for technical evaluation if they are not received by the deadline or do not meet the requirements stated in RTI’s University Handbook.

2. Proposals should be submitted in PDF format, 1 PDF file per proposal. File name should include project name and university abbreviation.

Pre-Proposal Meeting Information: Friday September 11, 2015 9:00 – 12:00

Austin Riverside Campus 118 E. Riverside Dr. ENV Conference Room, 1st Floor, 1B1A

Webex Information: Join the online meeting: Go to:

Join WebEx meeting Meeting number: 737 294 354 Meeting 1234 password:

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Proposal Proposals are due to RTI by 4:00 p.m. Central Time, Deadline: October 12, 2015. Email submissions should be sent to [email protected].

Project Statement 16-212