A Conversation with Nancy Huether Transportation Engineer with North Dakota Department of Transportation

Employee Portrait of Nancy Huether - Bridge Division

Nancy Huether (NDDOT)

Author: Lorella Angelini, Angelini Consulting Services, LLC

At the recent TSP2 MWBPP meeting in Milwaukee I met Nancy Huether, Transportation Engineer with the North Dakota Department of Transportation (NDDOT), who is the chair of the TSP2 Midwest Bridge Preservation Partnership Board of Directors.  I had a chance to speak with Nancy about bridge preservation strategies and implementation challenges in her state.

What does bridge preservation entail at NDDOT?

The bridge preservation program at NDDOT is still being defined. It is a given that focusing on bridge maintenance is one of our main goals. However, bridge preservation should be considered during all phases of the life of a bridge from conscientious design and construction to timely rehabilitation.

I believe strongly that bridge preservation starts with design and construction, which are critical elements in making sure we have good bridges and we can maintain them.  In other words, it is challenging to maintain bridges if they are not designed properly or constructed according to specifications.

I understand the design part. Could you tell me more about the construction aspect? Do you mean choosing the right materials and applying them correctly?

Yes, proper construction is very important. For example, when placing concrete it is important to consider ambient conditions such as temperature, wind, and humidity. Proper curing is also a critical component in ensuring long-lasting well-performing concrete.

I would like to reinforce the concept that preservation entails more than just maintenance. Construction plays a big part and cannot be overlooked.

Could you also speak of the design part? 

Using design methods that minimize maintenance is critical.  For example, the bridge division has been designing bridges for many years with integral abutments that minimize or eliminate the need for joints and the maintenance headaches that come along with them.

I understand that you have been in your new bridge preservation management position for about one year. Can you speak of this appointment?

I am a Registered Professional Engineer in the Bridge Division.  Just over a year ago, I was tasked with switching from the Hydraulics Section to the Structure Management Section to start a bridge preservation program.

Prior to my appointment, the NDDOT had no formal bridge preservation program.  That is not to say preservation concepts were not understood and considered, but there was no formal program. Bridge Preservation only entailed the Bridge Maintenance section that was added to the Maintenance Operations Manual in 2008.  This section, which was developed with the help of Bridge and District employees, laid out maintenance tasks and a schedule for completing those tasks.

What is your role with the Districts?

I do not supervise the implementation of bridge preservation in the eight Districts of the NDDOT.  My role is to support the Districts in their efforts by assisting with requests for education or by providing information about bridge preservation materials and procedures.

Encouraging Districts to focus more on bridge preservation activity and understand its value is one of my main goals. For this reason, as soon as I got the new bridge preservation assignment, I went to visit each District and learn about what they were doing.  The amount of bridge preventative maintenance being done in the eight Districts varied from a lot to very little.  The NDDOT is fortunate to have very capable maintenance personnel and I am confident that with additional support they can do much more.

What have you done so far?

I am in the process of developing the bridge preservation program. The first step of the program, which is nearly complete, is updating the Bridge Maintenance section of the Maintenance Operations Manual with current materials and best practices. We want to give more value to the Manual and see bridge maintenance operations more fully adopted by all the Districts.

The second step of the program entails finalizing a bridge preservation strategy that will eventually include not only maintenance, but also design, construction, and rehabilitation.

What is the major challenge that you are facing?

One major challenge involves getting more of the District personnel to better understand the benefits and importance of bridge preservation.  Since the NDDOT does not have dedicated bridge maintenance crews, bridge maintenance is only one of the many maintenance tasks the District Maintenance Sections are responsible for completing.

The bridges in North Dakota are in fairly good condition. However, sometimes when bridges are in need of repair, maintenance is deferred until small problems become bigger problems and contractors are called on to do the work.  This is a reactive mode of action.  Embracing the preservation concept means focusing on preventative maintenance and taking care of small problems before they become big problems. Increasing the awareness and benefits of pro-active maintenance will help us keep our good bridges good.

Do you have a bridge preservation success story you would like to share with the readers?

Yes, it is about the pro-active actions taken by one of our Districts. Approximately two years ago a District employee who has always had a keen interest in bridge preservation, was put in charge of maintenance for that District, where little bridge preventative maintenance had previously been done.

Under the guidance of this employee, the District has implemented a bridge deck preservation program that includes sweeping and washing the deck, sealing cracks with epoxy, and applying a silane surface treatment.

Although prescribed in the Maintenance Operations Manual, silane sealers had never before been applied by NDDOT maintenance crews.

The District developed the silane surface treatment application equipment and process on its own. It encompassed designing, assembling, and calibrating the spray equipment including spray bar, nozzles, tractor, pump and tank. They successfully treated several bridge decks this year.

At what time do you apply silane sealers as a bridge deck protection?

We apply the silane deck surface treatment as part of the initial construction, as soon as the bridge deck is completed and the concrete is cured. In doing so, the application becomes part of the design and the construction project.  We then prescribe the reapplication on a 6 year cycle.

Could you talk of your goals for 2017 and the upcoming years?

I have two main goals. The first is to assist our maintenance forces to continue taking initiatives and doing new maintenance activities in line with pro-active bridge preservation.  My role is to support them with information about products, processes, training, tracking, and any other areas needed, to the best of my ability.  This support, combined with their extensive knowledge and field experience, will help us achieve this goal.

My second goal is to get NDDOT bridge preservation program well documented, funded, and solidified.  The program will define the overall purpose of bridge preservation and outline key elements such as objectives, performance measures, and goals that support the NDDOT Strategic Business Plan. This program will also define a systematic approach to project selection and provide guidance for appropriate preservation strategies.  A well-defined bridge preservation program is important in cost effectively managing and preserving the NDDOT’s bridges.

Can TSP2 help NDDOT reach its goals? Is there more that TSP2 can do for you?

TSP2 continues to play a significant role in developing our bridge preservation program. I regularly use the information that is available on their web site.

TSP2 Regional and National Partnership Meetings are also of great value. They have given me, as well as others at the NDDOT, the opportunity to make connections with bridge preservation experts at other State DOTs, as well as with industry members, consulting engineers and contractors.

It is truly invaluable to be able to talk to people in other states about what they are doing and what has worked in solving specific bridge preservation problems. Thanks to TSP2 and the bridge partnerships, I have a large group of knowledgeable peers I can reach out to when questions or issues arise.  I can send one e-mail and receive 20 replies.

There is always something more that can be done. My hope is that TSP2 continues to strengthen its role as collector of information.  The TSP2 web site should be the first place people can go to find information, research, and publications about bridge preservation.

A Conversation with Pete Weykamp about LTAP

pw-for-tsp2
Pete Weykamp at LTAP Conference, Purdue University

Author: Lorella Angelini, Angelini Consulting Services, LLC
After leading the bridge preservation program with New York State DOT, Pete Weykamp has put his knowledge and experience at the service of the Local Technical Assistance Program (LTAP). Together with Ed Welch, Bridge Preservation Engineer for the AASHTO TSP-2 Program, and with the support of the National Center for Pavement Preservation (NCPP), Pete has started the Bridge Preservation LTAP training track for Local Agencies. I reached out to Peter in order to know more about the program. Additional information is reported in the flier, see linkage at the end of the post.

  • Could you speak of the reasoning behind the newly introduced Bridge Presevation training?

Over the last few years there has been great interest in getting Local Agencies (Cities, Counties & Towns) “up to speed” on the maintenance and preservation of their bridges.  In response to these needs Ed Welch and I have developed and implemented an Introductory/Grass Roots Bridge Preservation LTAP course for Local Agencies. The course is focused on the concept of bridge preservation and the advantages that it generates. It can be tailored to individual audiences adding or dropping topics depending on their capabilities and needs. The course can be presented as a full or half day as time permits.

Understanding the need for training and the development of municipal programs specific to the preservation of the non-State owned bridges is vital to the overall condition of the Country’s 608,000 bridges.  An effective/balanced bridge preservation program should include all aspects of preservation, first and foremost both reactive and proactive maintenance.

  • What is the target audience for the training program?

Our target audience consists of bridge maintenance personnel working for Local Agencies.  We have the ability to modify the training sessions based on the make-up of the different audience groups.  For example, for an audience of county highway supervisors and engineers we focus on Why specific preservation actions are necessary.  For an audience made up of field crews, a greater focus is place on How the actions are performed.  

  • Can you speak of the short and long term goals of the program?

Short term goals focus on a holistic approach to managing highway structures at the local level.  This includes topics that are essential for the preservation of locally-owned highway structures, such as involving industry partners and formalizing a process to deliver needed training.  

Longer term goals create a mechanism for local officials and crews to network, view hands-on demonstrations, and provide opportunities to participate in the AASHTO Regional Bridge Preservation Partnerships.

  • What is your specific role?  

My role is to develop training modules and provide instruction to for local agency training.  Working with Ed, we created training modules on Concrete Washing and Sealing, Expansion Joints, Repairing Concrete, Programming Bridge Maintenance, Developing a Bridge Preservation Program, and an overview presentation on Bridge Preservation Training for LTAP.  

I am currently working on training modules for Steel Coatings, Bolting, and Bearing Maintenance.  The modules will include videos and demonstrations.  I will continue to seek the assistance of industry partners in developing the training modules.  

  • How much was implemented in 2016 and what is expected in 2017

During the current year, training modules on Concrete Washing and Sealing, Expansion Joints, Repairing Concrete, Programming Bridge Maintenance, Developing a Bridge Preservation Program, and an overview presentation on Bridge Preservation Training for LTAPs were developed.  

In October, Ed and I conducted a training session during an event hosted by the Indiana LTAP through Purdue University.  Approximately 100 county highway supervisors participated in sessions on Expansion Joints, Programming Bridge Maintenance, and Concrete Repair.  An industry representative conducted a demonstration on the use of chemical anchors.  The half-day of bridge preservation training was received with substantial interest.    

For 2017, additional modules on the Protection of Structural Steel, Deck Overlay Options, Scour Remediation, and the Use of Sacrificial Anodes will be created. TSP2 will continue to outreach to Local Agencies offering bridge preservation training and the resources available through its program. TSP2 will also continue to explore needs and applications suitable for bridge preservation actions that can be implemented at the local level.

 

LINKAGE:

LTAP National Program

National LTAP & TTAP Association

Indiana LTAP – County Bridge Conference

Bridge Preservation Flyer for the LTAP Program

The New Concrete Surface Repair Technician (CSRT) Certification by ICRI

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logo

Author: Lorella Angelini, Angelini Consulting Services, LLC

The International Concrete Repair Institute (ICRI) recently launched a new program, the “Concrete Surface Repair Technician” (CSRT) Certification.

The International Concrete Repair Institute (ICRI), founded in 1988, focuses on being the leading resource for education and information to improve the quality of repair, restoration, and protection of concrete structures thus extending their useful life. Local chapters provide regional networking opportunities. Worldwide membership includes contractors, manufacturers, engineers, distributors, owners, and other interested professionals.

I think that the CSRT certification program can be of high interest to bridge preservation practitioners. For this reason I had asked a few questions about the program to Ken Lozen, ICRI’s Technical Director.

  • What compelled ICRI to set up the new training program?  There was demand in the concrete repair industry to educate and train individuals as technicians and inspectors on repair projects. The demand is driven by ACI 562-16 Repair Code language defining a qualified repair inspector as one who has been certified as an ICRI Concrete Surface Repair Technician (CSRT) – Grade 1, the credentials obtained from the ICRI CSRT Tier 2 full certification program.
  • Could you summarize the key elements of the program? For example, how is the evaluation performed and who performs it?  The web-based program includes five (5) online modules of education and training necessary for performing pre- and post-placement inspections and testing of concrete surface repairs. The training includes an introduction to types of concrete deterioration, presents a summary of repair materials and methods, and provides understanding of the requirements for a quality concrete repair. Training was developed from ICRI technical guidelines and other pertinent industry documents and standards. Certification requires passing five online training modules, an online knowledge exam, and a live or video recorded performance exam on four (4) applicable ASTM test methods.
  • How can a bridge preservation practitioner benefit from participating in this program?  A bridge preservation practitioner will learn the requirements necessary to perform pre- and post-placement inspections and testing of concrete surface repairs involving varying types of concrete deterioration, primarily embedded metal corrosion. Bridge preservation involves all types of concrete distress and construction, from foundations to piers, to its superstructure components. Exposed to harsh environments, bridges often experience premature and accelerated concrete deterioration that can reduce concrete durability and compromise structural integrity. Knowing the requirements for a quality repair is essential to preserving the bridge.
  • When was the program released?   The web-based certification program was launched in June 2016 with live performance exams now available at on-site locations. Register today at www.icri.org to receive introductory pricing. Volume discounts also available at reduced rates.
  • How has the program been received so far?  Participants have commented on the program’s comprehensive educational and training content and relevance for inspection and testing on concrete repair projects. The training is beneficial in the everyday lives of engineers/architects and contractors/manufacturers, from project managers/superintendents to technicians/laborers wanting to perform quality concrete repairs.

 

For more information Ken can be contacted directly at email hidden; JavaScript is required or (248) 358-6996

LINKAGE

ICRI CSRT enrollment page: http://www.icri.org/page/cert_techprogram#

ICRI Local Chapters: http://www.icri.org/?page=chapters

ICRI Concrete Repair Bulletin: http://www.icri.org/?page=CRB_current

A Conversation with Ed Lutgen MnDOT

ed-lutgen-picAuthor: Lorella Angelini, Angelini Consulting Services, LLC

I met Ed Lutgen Regional Bridge Construction Engineer with Minnesota DOT (MnDOT) at the Bridge Office in Oakdale, MN. We had a long conversation about bridge preservation strategies with the DOT and its implementation policies.

  1. What criteria does MnDOT use to classify bridge preservation? Is the MnDOT classification different from FHWA?

MnDOT classification for bridge preservation is slightly different from FHWA. In its “Bridge Preservation and Improvement Guidelines” MnDOT has created two categories: Preservation and Improvement. Bridge Rehabilitation and Bridge Replacement are classified under Improvement whereas FHWA classification places Bridge Rehabilitation under Preservation.

diagram1

Bridge preservation classification according to MnDOT Guidelines

In the past we had four different levels: Preservation, Improvement, Rehabilitation and Replacement. Preservation was defined as less than 30% of a new bridge cost, Improvement from 30 to 60%, Rehabilitation from 60 to 70%, Replacement was recommended when the repair costs exceeded 70% of a new bridge costs.

Since we were not doing many rehabilitation projects as defined in the previous system, we included Bridge Rehabilitation into Improvement. Within Preservation we also made a distinction between Bridge Maintenance and Major Preservation.

Preservation entails repairing deteriorated bridges with no significant change to their geometry or increase of load carrying capacity.  In a nutshell, it means preserving what is currently in place.  Concrete repair and cathodic protection are examples of typical preservation activities. Usually a preservation project is not meant to last more than 10-20 years and does not require bringing the bridge up to new design standards. However the bridge must comply with safety standards.

On the other hand, improvement applications entail modifying the geometry of the bridge and/or increasing its loading capacity. Rehabilitation projects are meant to last 50 years or longer and must meet specific design standards. Replacement projects have higher design requirements since they must meet full standards.

  1. Could you talk about the “Bridge Preservation and Improvement Guidelines”?

The Bridge Condition diagram is the focal element of the guidelines. It has been designed to be in line with AASHTO Subcommittee on Bridges and Structures (SCOBS) recommendations with regards to flow and targets to meet. However, we adapted the diagram to MnDOT bridge preservation classification and we linked it to National Bridge Inventory (NBI) General Terms. As a consequence, Bridge Maintenance (Green Code) entails NBI from 7 to 9, Major Preservation (Yellow Code) from 5 to 6 and Improvement (Red Code) from 4 to 0.

diagram2

  1. Could you speak about the project classification table?

The table provides a general guidance about scope of work and cost for MnDOT four preservation and improvement categories: Bridge Maintenance, Major Preservation, Bridge Rehabilitation and Bridge Replacement.

diagram3

As an example, if a major preservation project entails spending 80% of the cost of a new bridge, then the project does not meet the criteria indicated in the table. According to MnDOT, a costly project should provide more benefits than limited service life improvement and no increase of load carrying capacity. In other words, we do not want to spend 80% of the cost of a new bridge without significantly affecting key parameters such as service life, load carrying capacity and bridge geometry. However, there are exceptions that are evaluated case by case.

  1. Could you explain MnDOT decision-making process for the implementation of preservation and improvement projects?

The first step entails bridge safety inspection and NBI ratings, which are under the responsibility of District engineers. In Minnesota we have 8 Districts, each managing between 200 and 1500 bridges.

Data from the Districts is introduced in the Bridge Replacement and Improvement Management (BRIM) software program, which compiles the conditions of all bridge elements and calculates the probability for bridge service interruption.

BRIM uses deterioration curves to project bridge conditions out 20 years into the future.  We developed 6 different deterioration curve models for bridges in our State. In projecting MnDOT bridge inventory into the future, BRIM identifies bridges that are candidates for preservation or improvement projects. The software uses engineering logic and a data base that includes conditions and other critical factors, such as Average Daily Traffic (ADT).

In summary, in a 20-year period BRIM is able to project the time frame for a particular bridge to be repaired and it also recommends the type of repair, whether rehabilitation or preservation.

  1. How do you use information from BRIM?

Every year District engineers evaluate the BRIM output and make an intelligent decision on whether to advance or push back bridges in the priority list. This decision is taken in conjunction with the Bridge Office. As an example, we can foresee that a remote bridge will last longer than expected because it does not get a lot of wear and tear and de-icing chemicals are seldomly used.

Once a Bridge Performance Index (BPI) is established for each bridge, the next step of the process entails a spending evaluation through State Transportation Improvement Program (STIP). In essence, this is a funding mechanism that allows knowing what we will be spending for each bridge in 4 years before letting.

In order to avoid focusing on riskier bridges only, the BPIG recommended output should include 50% replacements, 25% rehabilitation and 25% preservation projects. This criteria prevents us to go back to the “worst come first” criteria, which is not in line with an asset management strategy.

Not all the Districts can meet the 50-25-25 criteria though. In the metro areas we are going to have a major bubble of rehabilitation projects in the coming years. I-94, which was built between the 60ies and the 70ies, has bridges that are becoming 50 years old. Since we cannot do all the necessary rehabilitation projects at one time, we are implementing preservation strategies in order to extend the service life of critical structural elements, such as bridge decks.

In the late 70ies and 80ies we did an overlay program that entailed overlaying 90% of our bridges decks with 2 inches of low slump concrete. In the last 5 years we have started re-overlaying bridge decks as part of a bridge preservation strategy. We have seen between 20 and 30 years of extended service life for low slump concrete overlays. However, an old deck with black bars is sometimes not worth another overlay. We also do not want to improve the deck of a bridge that has a 100-year old substructure. Ideally we would like all the different bridge elements to end at the same time.

  1. What about bridge preservation strategy for bridges in the rural areas?

The service life of rural bridges is on average longer than in the metro area where traffic demand requires the implementation of a significant number of rehabilitation and replacement projects.

Service life of bridges that belong to the County system is even longer than DOTs. Because of limited funds, Counties must allow bridges to get into conditions defined by low NBI rates, which, in some circumstances, can cause bridge service interruption.

With few exception, such as Hennepin County, City of Minneapolis and Duluth that have preservation procedures in place, Counties are in a reaction mode and adopt a “worst comes first” policy, which is mainly focused on bridge replacement.

  1. Back to the decision-making process, how does it develop when it gets to STIP?

District engineers calculate cost of projects in the BRIM – BPI output list that are related to their region and the 4-year program.  To do so they use a cost estimated worksheet that is included in the Guidelines. Once the cost of each project is defined, the information is introduced into the STIP, which provides the amount of spending by year and, as a result, defines the number of projects that can be implemented.

About one and half year before the letting, one of the Regional Bridge Construction engineers performs a field site visit together with a District engineer.  They walk individual bridges and complete a field review. This only entails preservation and rehabilitation projects, not replacement. A safety inspection is also performed.

For routine inspections, all non-culvert bridges are inspected every 24 months. If a bridge is classified NBI 4 or less (poor condition), then it gets inspected every 12 months.

Approximately one year from the letting, the Regional Bridge Construction engineer writes a recommendation report for preservation and rehabilitation projects. The report specifies actions to be taken but also includes information about estimated quantities. Basically the report works as a preliminary plan.

Once the recommendation report is signed off by the Districts, it comes back to the Bridge Office where design engineers start developing the contract plan and special provisions.  All repair recommendations reports are written by one of the four Regional Bridge Construction engineers, thus creating consistency between the reports and providing a level of quality control.

Districts also evaluate whether certain actions can be implemented by their own maintenance force. Each District has from 1 to 5 maintenance crews for a total of 190 bridge maintenance workers around the State. District maintenance crews usually perform jobs such as deck crack sealing, bearing greasing, concrete repair or joint replacements. Some Districts are able to perform more complex work, such as Accelerated Bridge Construction (ABC), overlays, painting, gusset plate replacement and even bridge replacements.

  1. When you mention a project, do you refer to a single bridge? Or can a project entail multiple bridges?

A project can encompass a number of bridges. We are about to start the North Lowry tunnel project, which includes 52 bridges from Nicollet Ave to Shingle Creek on I94. Out of the 52 bridges only 1 entails rehabilitation, the other 51 concern preservation for a total of $15 M. We are planning to do patching, overlays, concrete repairs, delamination removal, Fiber Reinforced Polymer (FRP) and Glass Fiber Reinforced Polymer (GFRP) applications. These last two technologies will be used as strengthening system but also to make repairs last longer in areas close to traffic where there is salt spray.

For a major project like this we hired a consulting engineer, to help with field investigation and preparing the final design. Repair recommendations for all bridges were developed by a Regional Bridge Construction engineer.

  1. What happens after the letting?

Once a contract is awarded, the Regional Bridge Construction engineers support the contractor for any questions or issues they may have.

At contract completion, bridges can be upgraded according to NBI rating. However they can also maintain the same ratings.

  1. Do you have a preservation success story that you would like to share?

We are proud of the restoration of the Lester River Bridge over the mouth of the Lester River along Lake Superior shoreline, which was built in 1924-25.  It is a beautiful arch bridge that is considered as a gateway to the North Shore. It has masonry abutments and side walls over the concrete arch.

Due to the high level of chloride contamination, we had to remove all masonry down to the top of the arch and apply a comprehensive cathodic protection system that included a variety of solutions suited to different conditions. In addition to design standards, we met the standards from historic preservation.

  1. What can TSP2 do for you?

We consider TSP2 as an organization that can help us get information about new products and technologies for bridge preservation and rehabilitation, especially in relation to service life extension and cost-benefit. We are also interested in knowing of other States’ experience with new technologies, in particular in the Midwest.

We have started evaluating the use of GFRP rebars for bridge decks so as to avoid steel corrosion. We currently use epoxy coated steel bars for bridges that cost less than $25 M. For bridges that cost more than $25 M we use stainless steel bars.

We are also evaluating the use of GFRP bars in the substructure areas that are more prone to deterioration, such as underneath deck joints or abutment seats. Leaking joints are a source of problems since they cause concrete deterioration and spallings in the substructure. We tend to eliminate joints whenever it is possible.

We have started using other innovative technologies, such as micro and macro fibers in casting decks and epoxy chip seal especially, in situations where we have deck cracking.

We are doing Accelerated Bridge Construction (ABC) and we are addressing mass concrete issues.

In addition to new products and technologies, we are also interested in getting information about prioritization of applications in other DOT States and successful solutions that solved specific problems.

 

LINKAGE:

Minnesota DOT “Bridge Preservation and Improvement Guidelines – Fiscal Year 2016 through 2010” – http://www.dot.state.mn.us/bridge/pdf/bridge-preservation-and-improvement-guidelines-2016-2020.pdf

 

A Conversation with Joshua Sletten, Bridge Management Engineer with Utah DOT

Josh-and-Panama-Ninos
Joshua with the kids of Panama

Author: Lorella Angelini, Angelini Consulting Services, LLC

Some time ago I published a post about the initiative taken by Joshua Sletten, Utah DOT, who traveled to Lura, Panama to help build a pedestrian suspension bridge with the “Bridges to Prosperity” organization.

I met Joshua at the recent AASHTO Subcommittee on Bridges and Structures (SCOBS) annual meeting in Minneapolis, MN, where I live. Joshua, an expert on bridge preservation, sits on the AASHTO SCOBS technical committee T-9 “Bridge Preservation” that is chaired by Bruce Johnson with Oregon DOT.

I had a brief conversation with Joshua about his experience in Panama.

Was the goal accomplished? Did the construction of the suspended pedestrian bridge in Panama go as planned? 

Yes, the goal was fully accomplished. We actually completed the bridge a little faster than we had scheduled.  We had planned to complete the project in 12 days, and we finished after 8. We also finished under budget. I think everybody was pretty happy with it.

We worked well together as a team. We brought in local community members that helped us build the entire bridge. We had translators to help with language differences. Everybody played their part well.

At-Work

What was your role in the project?

I was the logistic manager, in charge of getting everybody to the bridge at the scheduled time. I also managed transportation, arranging meals and lodging in Panama City.

 What stands out in your memory about this experience?

The biggest thing for me was connecting with people, the volunteers that traveled to Lura, Panama to help build the bridge and the local community. I also had a great time playing with the local children. After work, we played kickball, softball and football. I even taught the kids how to throw a Frisbee.

I will surely remember the inauguration day, when we played music during a traditional jam.

The other big thing that stands out to me is having been able to build a bridge that was desperately needed by the community. The bridge will serve the community for generations to come. This is what makes me proud to be an engineer. I am definitively going to remember this.

Helping-Hand

Would you recommend this experience to other engineers?

I learned a lot from this experience. I arrived to the bridge location, deep in the Panamanian jungle, got unplugged from all the technology and started working with a team that was motivated and like-minded to build a 150 ft. long suspension bridge  in a short amount of time.

It was a memorable, once in a lifetime experience that I highly recommend to anyone.

Obviously, one has to overcome some challenges, like staying in a tent, doing hard work and labor with your hands, and not being afraid of sun exposure or getting attacked by mosquitoes.

How long did you stay in Panama?

I was there for two weeks. When I got there the local community had already completed the foundation. The entire bridge, from inception to inauguration, took approximately three months to build.

Will there be any preservation activity for the bridge that you helped build?

We spoke at length with the local people, who are very proud of the bridge, about the importance of proper bridge maintenance.  We wanted to reinforce the concept that in order to keep the bridge in a state they can be proud of for years to come, it has to be well maintained. We talked to them about how to replace the planks when they begin to wear out. We showed them how to maintain or replace other critical elements of the bridge.

Lura-Panama---Suspension-Bridge-Construction-Team

 

The ECC Bendable Concrete

Author: Lorella Angelini, Angelini Consulting Services, LLClorella

Recently, CNN aired a report about America’s crumbling infrastructures. One of the topics was the so-called “bendable concrete” that was presented as an innovative solution that could extend the service life of US bridges.

Bendable concrete, officially called Engineering Cement Composite (ECC), has been developed over the last 10 years by Prof Victor Li, Civil and Environmental Engineer at Michigan University, Ann Arbor, MI. ECC is designed to overcome the inherent brittleness of concrete by having high tensile ductility and the ability to self-heal tight cracks. Its ductility allows constructing safer concrete structures that bend under extreme loads but do not break.  Crack control and self-healing provide higher concrete durability in a variety of environmental conditions.

ECC has been applied in Japan for a bridge deck that it is expected to last 100 years despite severe cold weather environmental conditions and limited thickness (2 inch) of the slab. The properties of ECC concrete allow structural elements to be designed with reduced dimensions and thus can provide significant cost savings to the owners by offsetting current ECC cost by volume, which is approximately 3 times higher than ordinary concrete.

ECC was also used for bridge deck construction in Michigan on Interstate 94. The application has been closely monitored by the University of Michigan and the Michigan Department of Transportation.

In 2015 ECC won the prestigious Construction Industry Council (CIC) Innovation Award with ECC.  CIC, which is based in Hong Kong, promotes sustainable innovation for the construction industry.

 

LINKAGE:

Read CNN news article: ”America’s infrastructure: Beams disintegrating under bridges”

http://www.cnn.com/2016/05/25/politics/infrastructure-roads-bridges-airports-railroads/

 

Watch ECC bendable concrete’s videos:

https://www.youtube.com/watch?v=FW3U3-7Qr_I

https://www.youtube.com/watch?v=dHGrAVS6UUQ

https://www.youtube.com/watch?v=TUxXzjzan5k

 

Participate in LinkedIn discussion about “bendable concrete”

www.linkedin.com/hp/update/6143804673406042112

 

Participate in Twitter discussion about America’s crumbling infrastructures

https://twitter.com/cnnpolitics/status/735574215210979328

 

Read ECC Wiki page

https://en.wikipedia.org/wiki/Engineered_cementitious_composite

 

Learn about CIC and its Innovation Award

http://cicinnovationaward2015.hkcic.org/en/home

 

Healer-Sealers for the Protection of Bridge Decks

lorellaAuthor: Lorella Angelini, Angelini Consulting Services, LLC

It is well-known that innovation represents one of the key elements for a successful bridge preservation strategy. An interesting innovation technology for bridge deck protection entails the so called healer-sealers. These are very low viscosity liquid-applied resins that penetrate by gravity into the hairline cracks and surface pores of concrete with the result of preventing infiltration of water and contamination by chlorides.

Different healer-sealer technologies are available, such as, Methyl Methacrylate (MMA), High Molecular Weight Methacrylate (HMWM ), epoxy and polyurethane. They all have in common an application method that consists in cleaning and opening the concrete surface, flooding it with the resin, and broadcasting aggregate (mainly sacrificial) before the resin starts setting. Performance properties vary between the different technologies as outlined in the snapshot information reported below. This information, which provides a general guideline about the technologies, is taken from technical data guides of a selection of brands that are present in the bridge preservation environment.

In comparison with other bridge deck protection solutions, healer-sealers are economical technologies both in terms of material and labor. This affordability should make it easy to apply healer-sealers over new decks. However, in the majority of cases, they are applied on an already contaminated deck after a few years following the completion of bridge deck construction, which in turn generally reduces their effectiveness.. For best performances, healer-sealers should also be re-applied periodically, on average every 5-10 years depending on the rate of of deck surface deterioration by traffic.

High Molecular Weight Methacrylate (HMWM)

  1. Viscosity: <25 cPs
  2. 100% solids
  3. Elongation: 5 – 30%
  4. Compressive strength: 3,000 – 8,000 psi
  5. Tensile strength:  500 – 1500 psi
  6. Aggregate should be placed within 15 – 20 minutes of resin application
  7. Application temperature (ambient):  50 – 100
  8. Traffic reopening:  4 – 8 hrs. after application (depending on ambient temperature)
  9. Flash Point > 200 °F

Methyl methacrylate (MMA)

  1. Viscosity: <5 – 10 cPs
  2. 100% solids
  3. Elongation: 4.5 – 5%
  4. Compressive strength: >12000 psi
  5. Tensile strength: > 8000 psi
  6. Aggregate should be placed within minutes of resin application
  7. Application temperature (ambient): 20 – 105 (with accelerator for low temperatures)
  8. Traffic reopening: 1 hr after application (depending on ambient temperature)
  9. Flash Point >50 °F

Very Low Viscosity Epoxy

  1. Viscosity: 100 cPs
  2. 100% solids
  3. Elongation: 10%
  4. Compressive strength: 8000 – 12000 psi
  5. Tensile strength: > 7000 psi
  6. Aggregate should be placed within 20 – 30 minutes of the resin application
  7. Application temperature (ambient): 40 – 90
  8. Traffic reopening: 6 hrs after application (depending on ambient temperature)
  9. Flash Point >200 °F

Ultra-Low Viscosity Epoxy

  1. Viscosity: 40 cPs
  2. 75% solids
  3. Elongation: 50%
  4. Tensile strength: 2500 psi
  5. Aggregate should be placed within 15 minutes of resin application
  6. Application temperature (ambient): > 50
  7. Traffic reopening: 4 hrs. after application (depending on ambient temperature)
  8. Flash Point:  > 100

Polyurethane / Polyurethane- hybrid

  1. Viscosity: 12-16 cPs
  2. Elongation: < 10%
  3. Compressive strength: 3000 psi
  4. Tensile strength: 4500 psi
  5. Aggregate should be placed immediately after resin application
  6. Traffic reopening: 10 – 90 minutes after application (depending on ambient temperature)
  7. Application temperature (ambient):  20 – 100
  8. Flash Point : >200°F

There a number of publications and research reports about healer-sealers. Some of them include a comparison with silane sealers.  A few links are reported below.

From Minnesota DOT:

http://www.dot.state.mn.us/research/TS/2014/201434.pdf

From Oregon DOT:

https://www.oregon.gov/ODOT/TD/TP_RES/docs/reports/2010/crack_sealer.pdf

From Colorado DOT:

https://www.codot.gov/programs/research/pdfs/2014/sealers.pdf/

From Kansas DOT:

http://ntl.bts.gov/data/letter_ak/KS-98-4.pdf

From Utah to Panama Following a Humanitarian Call

Author: Lorella Angelini, Angelini Consulting Services, LLC

Do engineers have a warm heart? Yes and a generous one!
Behind their notoriously serious face, engineers have a generous attitude, which responds to their social call. At the core of their work there is a dedication to servicing the communities by designing sound structures that are safe and last long, even in difficult environmental conditions.

A story that underlines engineers’ generous attitude is being written by Joshua Sletten, bridge management engineer with Utah DOT. Leaving temporarily aside his responsibility of managing bridges across the state, Joshua has taken the commitment of building a 150-foot suspension bridge in Luna, Panama, thus replacing the rickety, life-threatening bridge that is currently used by the local population.

Joshua will lead a 10-person volunteer team with “Bridges to Prosperity”. This non-profit organization based in Colorado has an inspiring mission, which entails providing isolated communities with access to essential health care, education and economic opportunities by building footbridges over impassable rivers.

LINKAGE
Information and a video about Joshua Sletten project in Panama can be seen here:
http://www.ksl.com/?sid=38846775&nid=148
Information about Bridges to Prosperity non-profit organization can be found here:
http://bridgestoprosperity.org/
https://www.facebook.com/BridgestoProsperity
https://en.wikipedia.org/wiki/Bridges_to_Prosperity

A Conversation with Jeff Pouliotte about Coating Steel Bridges

Jeff Pouliotte picAuthor: Lorella Angelini, Angelini Consulting Services, LLC
Coating steel bridges is a key technical topic with bridge preservation. It comes as no surprise that there are ten TSP2 Working Groups addressing the different aspects of this practice, from spot painting to surface preparation.

One of the experts in this field is Jeff Pouliotte, State’s Structure Maintenance Engineer with Florida DOT (FDOT). Jeff is the chair of TSP2 “National Bridge Preservation Coatings” Working Group.

Where does your interest for protective coatings for steel bridges come from?
Having worked for FDOT in design, construction and maintenance for many years, I realized that steel bridges often require repaint after as little as 12 years, while these applications should last 20-25 years. For this reason, bridge owners have to repaint their steel bridges many more times than they should have to over their service life. I also realized that there is ample room for improvement with this technology, for example, using high performance coating systems or weathering steel.

In Florida, as default systems, we have adopted the use of weathering steel for environmentally suitable locations and an inorganic zinc single-coat paint system for more severe environments. For aesthetically sensitive locations, we opted to retain a 3-coat inorganic paint system with a clear top coat for color retention and gloss.

How did you take the lead in the national effort to improve the practice of steel bridge coating?
It started with sharing my experience with the protection of steel bridges in aggressive environment at the South East Bridge Preservation Partnership (SEBPP) in 2012 in Atlanta, where I gave a presentation.

After the presentation, I was asked to put together a list of recommendations for how owners could achieve improved service life for their steel bridges. I subsequently put together a group of volunteers from the SEBPP and the AASHTO National Transportation Product Evaluation Program (NTPEP), which was comprised of a few State employees and Industry representatives, which became the SEBPP Paint Group.

The group’s first products were a Report entitled “A Rational Approach for Planning Bridge Repainting Projects”, a calculation methodology to compare recoating options, and the SEBPP survey to determine Best Practices for Coating Structural Steel. The Calculator focused on cost comparisons between spot painting, overcoating and the removal and replacement of the entire existing coating system. It also included a methodology to compare mobilization and construction costs, life-cycle costs, as well as maintenance and protection costs.

The Report identifies the significant aspects of recoating operations that affect quality, such as: engineering evaluations for in situ coating systems, surface preparation, coating application, specifications, contractor, CEI and owner training and qualifications. At the urging of the AASHTO Subcommittee on Maintenance (SCOM) we modified the Calculator and the Report to include user costs for people sitting in traffic awaiting construction to clear up. I presented results of both at National Bridge Preservation Partnership (NBPP) in Orlando in 2014.

After the meeting in Orlando a consensus was reached to take the program to the national level. The Group has been renamed the NBPP Coatings Group, to acknowledge our national status and to formally acknowledge our interest in coating systems other than paint. The makeup of the Group currently includes experts from other State DOTs, NTPEP, Consultants, Suppliers, Delegates to the AASHTO Subcommittees for Bridges and Structures, Maintenance and Materials, TRB, SSPC, NACE and Researchers. We focused on promoting an AASHTO Domestic Scan “Bridge Recoating Best Practices”, which got support and endorsement from AASHTO Subcommittee on Bridges and Structures (SCOBS), SCOM, all four TSP-2 National Bridge Preservation Partnerships, and the Transportation Research Board (TRB). The goal of the Domestic Scan is to gather knowledge from DOTs across country on best practices for steel bridge coating protection. The Domestic Scan was subsequently accepted and is scheduled for completion in October 2016.

What is the short term goal for the NBPP Coating Group?
The goal is to promote knowledge that will allow Owners to improve the durability of coatings for steel bridge coatings. The report “A Rational Approach for Planning Bridge Repainting Projects” identifies the following as key aspects for having a successful bridge recoating project: performing an engineering evaluation of the existing coating system to determine if the substrate is suitable for overcoating; proper surface preparation; proper coating application; proper training for Contractors, Inspectors and Owners; and good specifications.

The Group is advocating the adoption of the Report’s conclusions, is focusing on finding ways to promote NACE or SSPC coatings training for inspectors and contractors, and is trying to involve the contracting community in our activities for their insight and knowledge.

And what is the long term goal for the Group?
The primary goal is to promote long lasting cost effective coating systems. In accordance with this goal, the Group recently endorsed a research project to collect technical data and develop design guidelines and specifications for duplex coating systems, consisting of a galvanized and/or metalized bottom coat with a high performance paint system top coat. We have already received support from SCOM for this research project. I also raised this issue during the midyear meeting of the AASHTO Subcommittee on Bridges and Structures’ T-9 Technical Subcommittee for Bridge Preservation where I am the Vice Chair. As a result, T-9 will be asking SCOBS to also endorse this research project.

How does the Group plan to promote awareness of the financial benefits of supporting the use of best practices in steel bridge coatings?
We are planning to start a research project to help Owners develop methods to convince Legislators of the benefits of bridge preservation activities, and to free up more funding in this area. In parallel we should find a way of supporting those Owners who specify longer lasting more durable coating systems and have the courage to hold contractors accountable and reject insufficient work. Decision makers need to understand that longer lasting coating systems save money over time.

What challenges are the Group currently facing?
We need to create a liaison with all the stakeholders involved in the coating of structural steel bridges. We have reached out to the AASHTO Subcommittee on Maintenance, Construction and Materials, NTPEP, and the National Steel Bridge Alliance (NSBA). The more people are involved, the more we can identify and address problems to achieve better results.

There is a great need to assemble and transfer knowledge. For example DOT structural and maintenance engineers as well as design engineers are not necessarily steel coating experts, so a liaison with other stakeholders is essential to achieve better results.

It would also be helpful to solicit advice from contractors, who can assist in setting up contract requirements and specifications. If contracts and owners hold contractors accountable, good contractors will thrive, while contractors who perform subpar work will see a need to improve which should help avoid the financial strain of redoing work.

And so, are contractors going to be part of the Group?
I would love to have contractors in the Group, but unfortunately we have not been able to attract them. Contractors could greatly help the Group shape an innovative bid process that awards contracts based on the best value and not the lowest cost. In Florida we have experimented with warranties as a first attempt to try to achieve this goal.

What is your experience with product Manufacturers?
Since Owners are in general reluctant to try new products, a major challenge faced by Manufacturers is the release of new products that do not have a track record. Accelerated testing is good way to prove the durability of coatings as an alternative to the track record. However not all Owners have the same Lab capabilities as FDOT in carrying out this challenging test.

Any closing thoughts?
A steel bridge coating system that lasts longer saves money over time and extends the overall service life of the infrastructure. Future generations will reap the financial benefits of long lasting coating systems, due to reduced maintenance costs. The commitment of our Group is to raise awareness of different solutions and provide tools to help Owners make correct choices.

Links:
TSP2 Bridge Preservation Coating Working Groups:
https://tsp2bridge.pavementpreservation.org/technical/coatings/

Jeff Pouliotte’s Presentation at TSP2 National Meeting in Atlanta in 2012
https://pavementvideo.s3.amazonaws.com/2012_SEBPP/PDF/10%20-%20FDOT%20New%20Directions%20in%20FDOT%20Steel%20Corrosion%20Protection%20-%20Jeff%20Pouliotte.pdf

Jeff Pouliotte’s Presentation at TSP2 National Meeting in Orlando 2014
http://nbppc2014.org/opening-a- rational-approach- for-planning- bridge-repainting- projects-pouliotte/
https://pavementvideo.s3.amazonaws.com/2014_NBPPC/PDF/4A%20-%20SEBPP%20Paint%20Report%20Presentation%20-%20POULIOTTE.pdf

Paint & Coating TSP2 Video Library:
https://www.pavementpreservation.org/video_library/bridge/Paint_Coatings.html
SEBPP Paint Report Presentation – Pouliotte
Report – A Rational Approach for Planning Steel Bridge Repainting Projects
Bridge Cost Analysis – Calculator

Current and Futuristic Methods to Seal Concrete Cracks

Lorella Angelini
Author: Lorella Angelini, Angelini Consulting Services, LLC

There are many ways to design concrete mixes. Different types of ingredients and dosages can be used in various combinations so as to respond to construction and specification requirements. However all concrete mixes share one basic, common denominator: they should not develop cracks, even under stress conditions.

Not only are cracks aesthetically unpleasant, they are also very detrimental since they provide a way of entry for contaminants, such as chlorides and sulphates, into concrete. Once it penetrates into the cracks, water alone can cause concrete spalling by freeze-thaw cycles.

Between the technologies for permanently sealing cracks in concrete, epoxy resins are widely used, especially for structural cracks. Epoxies have great adhesion to concrete, high compressive and tensile strength, volume stability, and are available in a variety of formulations for different types of applications. For example, wall cracks can be sealed by injecting epoxies at low or high pressure, preferably moving from the bottom to the top of the wall. Other types of epoxies with low or ultra-low viscosity can be used to seal cracks in concrete decks or pavements. In this case the material is fed into the cracks by gravity. This application method is also used with HMWM (High Molecular Weight Methacrylate) or MMA (Methyl Methacrylate) resins that have a level of viscosity so low that can be compared to water.

In the future these proven technologies may have to confront with a new, experimental method to seal concrete cracks that is based on the use of natural bacteria. By introducing bacteria into concrete cracks, simply using a garden sprayer, long, thin cracks can be sealed in a relatively short time with the limestone compound produced by the bacteria, when these organisms come in contact with water. More information about the sealing mechanism is reported in the links. The Netherlands and the UK appear to be on the leading edge of this exciting development program.

Epoxy injection:

http://www.concretenetwork.com/concrete/crack_injection/basicsteps.html

http://www.concreteconstruction.net/repair/epoxy-injection-for-cracked-concrete_o.aspx

https://www.concrete.org/store/productdetail.aspx?ItemID=503707&Format=DOWNLOAD

Gravity fed epoxies:

http://docslide.us/documents/crack-repair-by-gravity-feed-with-resin.html

Gravity-fed MMA:

http://trrjournalonline.trb.org/doi/10.3141/2202-10

Bacteria-healed cracks:

http://digg.com/video/concrete-bacteria-heals-cracks

http://www.nbcnews.com/id/40201539/ns/technology_and_science-green_innovation/t/designer-bacteria-can-heal-cracks-concrete-buildings/#.VujQVeYk3HA