ABC-UTC: research proposals 

In collaboration with the ABC-UTC, the identification of research topics to advance the strategies and technologies used for Accelerated Bridge Construction is being pursued as part of the 2017 Industry Feedback Poll. 
Listed below you will find some research topics that have already been developed into draft Research Needs Statements (RNS), while others are Research Topic Ideas (RTI) that have come up in past discussions. 
Regardless of the status, all topics shown below are up for consideration to further prioritize, develop, or refine using your input as a means to better facilitate available resources to the areas of need.
--After reviewing the topic(s) in the left column, please rate and provide any additional comments by selecting the "Review and Rate" link.      
--If there is a particular research topic that you would like to be more involved in, include your contact information on the optional part of the "Review and Rate" links for further collaboration.   

--If there is an ABC related research topic that isn't covered, consider submitting your idea to the: Additional ABC Research Topic link. 

--Your rating will be posted automatically in the column to the right. 
         --Comments along with any new topic ideas will be posted daily.  

 FEBRUARY 21, 2017
12:00 PM PST


 1. Development of guidance for establishing effective and efficient timelines and incentives for ABC. 
                 Proposal link
                 Review & Rate link


- Developing "rules of thumb" for Owner's on when to use or not use and how high/low to set Incentives and Disincentives on "common" factors such as size of project, dollar amount, complexity, etc... with input from the construction side of the industry would be useful for planning purposes. 

- For our agency, this is done by our traffic group.

- I think this could be an output of topic #6

- Lessons learned from tackling the 'areas of slowing downʺ and how successfully the hurdles were bypassed.

- This research will help with efficient implementation of developed ABC Technologies. Utilizing the UTC data base of constructed ABC Projects will give research results a high degree of credibility.

- Unclear how general guidelines will assist with specific projects and related goals.

- I consider this a budget concerned initiative. While ABC kind of became "hot", we don't want to use ABC even when it does not make a lot of sense. So this will help agencies make good use of scarce funding.

 2. Planning, design, fabrication, and installation strategies for Modular Decked Beam (MDB) elements 

                Review & Rate link


- This is an RTI seeking further input for the need to investigate techniques used with MDB elements - which are prefabricated, predecked superstructure elements that are typically connected using longitudinal closure pours. 
- An item to consider is to not design the connection, but develop a performance based special provision that Owner's can use that addresses durability, service, and strength rather than to design each and every connection that might need to get modified to accommodate the delivery and installation needs. 
- An inspector's field guide may be something of value. 

- It seems that many pre-decked elements use a semi-integral detail, perhaps to address the need for speed in the field; however, many of the bridges that make use of these are small enough for a fully integral detail that would result in less maintenance.
- We need proven ways to expedited the back wall/abutment/approach slab once these are placed.  Identifying what works well/what doesn't would be useful.   

- The hooks in the overhang can become problematic.  A common practice is to thicken the slab; however, this adds weight to an already heavy element that may/may not have a parapet installed.   This also applies to prefabricated concrete deck panels. 

- Consider use of UHPC with this method

- This is an item that can be addressed via the best practices learned from various states with experience in this subject.

- Demonstrate the practices that address concerns on the development of the better MDB connection elements, and QC/QA during the construction.


 3. Performance comparison of in-service full-depth precast concrete deck panels to cast in place decks               

                Review & Rate link


- This is an RTI.  The idea is to reference PCI's State of the Art Report that identify ~40 deck panels in service beginning around 1971and compare how they are performing to cast in place bridges built in the same era under a same environment.   

- Demonstrating the performance of real projects the benefits of confined concrete to unconfined concrete would better support the many reasons for Owner's/Designer's to consider deck panels over cast-in-place.  
- Should also pick up what design/detail practices work well and what didn't for the deck panels. 
- Consider including collaboration with FHWA's Long Term Bridge group on the protocols of data collection, testing, etc...  
- May find out that many of the deck panels have an overlay.  If so, plan on how to address their impacts to the performance.   

- Emphasis should be placed on long-term performance assessment.

- Need LCA report. how much energy has been used and or saved. report on environmental sustainability must be prepared with prefabrication and performance data.

- This is a great RTI. As engineers we don't like to pushed one way or another. We feel the pressure of ABC but we need data to support one way or another. We need performance information.

- It's helpful to evaluate durability of already constructed ABC projects to develop guidance for future construction.

- Comparison needs to consider the precast system with emphasis on closure material performance (especially accelerated closure PCC), composite action of panels w/ beams over time, etc...  I'm not sure what was used for closure materials 40 years ago is the same 1-2 hour materials we are being forced to use today with so many overnight applications - this is where I see problems / poor performance.  We have placements where the closure has cracked, scaled, and leakage occurring after less than 1 year...  No one considers this in their life cycle cost analysis with routine maintenance needs.

- Report on energy cost/green house gas emissions comparison for PC deck panels and cast-in-place. Report on effectiveness of joint detailing, specifically the material used in the joints (UHPC vs grout or high strength concrete or rapid set concrete.

- Although this would be helpful in choosing one alternative versus another, we will always consider both.


 4. Labor, equipment, and production rates for Accelerated Bridge Construction

                Review & Rate link


-This is an RTI.  The increased use of ABC projects in the past 5 to 6 years is leaving a legacy of production information that would be useful to the design and construction community for their planning and bid submittals.      

- Similar to what RSMeans provides, this would be helpful for designers that are developing engineer's schedule. 

- Maybe this should primarily be focused on bridge construction in general, and pick up the strategies used for ABC as an additional task within the research project?

- Is this something we should be doing?  How does RSMeans get their data?

- In order to properly represent the advantages of ABC over conventional alternatives it is imperative to be able to compare working days.  This allows comparative evaluation of impacts as well as total project cost.  This information is lacking making it difficult to produce quick planning studies to promote ABC alternatives.  Reliable ABC construction rates will lead to increased implementation of ABC.

- Contractors have a good handle on this

- Along the same lines as deciding when to use ABC, this is also a good way of estimating and determining the cost of abc. This will help decide when to use it and rate it.

- MnDOT is pursuing this:     Link 1

- Other similar/parallel work: Link 2 - Montana DOT

                                              Link 3 TxDOT

                                              Link 4 TxDOT


 5. Best Practices used for Strategic Public Communications for ABC projects

                 Proposal link
                 Review & Rate link


AFH10 also has a similar RNS statement at the following Link . 
- Maybe this should also consider the internal communications within State DOT's and their external outreach to their engineering and construction community that are using ABC more routinely. 

- Combine with No. 1.

-It is always good to establish best practices.


 6. Updating the "Best Practices in Accelerated Bridge Construction Techniques" report

                 2011 Report
                 Review & Rate link


This is an RTI to see if there is value to conduct another national and/or international scan on ABC.  The last time this occurred (see report link) was back in 2011. 

- Should send out reminders of where this information is located.

- It is always good to establish best practices and keep them updated. It may be advisable to give the state time to accumulate enough experience with ABC, i.e., establish some of those best practices.

- Lots of links within the link and much time needed to adequately review the material.

 7. Rapid Construction of Pre-fabricated Substructure elements for Durable and Sustainable Bridges using Fiber Reinforced Polymers (RFP) 

                 Proposal Link
                 Review & Rate link


This is an TRB collaboration RNS between AFF00(2) and  the TRB Standing Committee on Fiber Reinforced Polymers (AFF80).

CFT is showing great promise for ABC because a lot of on-site activities, procurement and management/coordinating steps are simplified compared to cast-in-place conventional substructure columns.  Using FRP shells in lieu of a steel shell may bring additional benefits - not just for ABC, but also for seismic considerations.  .

Allowing for an FRP casing to bid as an alternative to a steel casing may provide the contractors more flexibility with the managing the items related to supply lead times and costs.  Both would have to compete with each other - which can lead to additional savings for the Owner. 

- FRP is the future to many of our current problems. This should not be limited to shells as these can be damaged. Internal FRP needs to be developed and become widely used.

- Substructure itself is an important element; it should not be confined to FRP.

- The use of FRP in substructure elements in saturated environments is important for the broader use of FRP.  Why is a shell being considered?  Column wrapping is not new or innovative.  However, using FRP as internal reinforcement in saturated conditions is needed.

- Section II of the RNS appears to proposes that the FRP shell be used as structural reinforcement. This would be similar to a CFT. FRP is stronger but far less ductile than steel. Though suitable for confinement, FRP does not seem a good candidate for main column bars in seismic regions. If moved forward, suggest this research focus (also) on use of FRP 'bars' in elastic PC components such as ABC decks in corrosive environments.

- Interesting proposal. Industry specific. It may be funded through various channel, not necessary ABC.

- I will be looking forward over the next twenty years +/- to see if this strategy corresponds with benefit, durability and longevity.

- It would be very important to come up with design guidelines as a result of this study.


-- Given the extensive use of ABC techniques to construct bridges, I believe State DOT and other owners may want to consider their ABC bridge(s) performance when compared with their “standard” bridge construction practices.  Even if it is something as simple as Was Bridge Constructed with ABC techniques  (1 for yes , 0 for no).  Additional items might be what Element was constructed with ABC (1 deck, 2 superstructure, 3 substructure).  Methodology employed, etc.  Research how this could be done simply but effectively within the NBIS framework. 

-- I would be interested in looking at the funding/financing components that are available to Owner's to either accelerated individual projects and/or accelerate a high volume of projects similar to Pennsylvania DOT RBR program.  From my understanding "bundling of bridges" was included in MAP21 legislation - is anything being done about it with the FHWA and DOTs?

-- This may apply to seismic as well as ABC since the need for simple/quick connection details and for plastic hinging.  Has anyone looked into the use of higher grade reinforcement steel in the column, cap, and/or footing (ie. Gr. 80) with lower grade reinforcement steel in the plastic hinge zone (ie. Gr. 60 or less)?