Author: Lorella Angelini, Angelini Consulting Services, LLC
I recently spoke with John Buxton, Bridge Maintenance Engineer / Deputy Chief Engineer at Maine DOT. He is in charge of the Bridge and Structures Maintenance Division at the Bureau of Maintenance and Operations. In addition, he is connected to the executive office as the Deputy Chief Engineer. John is fully committed to bridge preservation. His many years of experience in this field make him a go-to person with TSP2.
What does bridge preservation entail at Maine DOT?
Bridge preservation currently represents 70% of Maine DOT’s maintenance budget. While in the past we used to do a lot of rehabilitation and restoration type of work, currently preservation is the primary focus for the maintenance department. Preservation entails activities such as replacing and repairing joints, making sure that all joints are sealed, sealing concrete with water repellents, painting bearings and beam ends, and keeping concrete wearing surfaces in good condition. We are trying to address the deterioration of bridge elements before it becomes a problem. It is evident that it is better to spend a few dollars in preservation than thousands of dollars in restoration.
Does your 70% of maintenance budget include all preservation expenditures at Maine DOT?
In addition to maintenance, also the capital side has a budget for preservation activities, which mainly entail full painting projects. We are treating concrete with silanes, not only the deck but also vertical surfaces, such as piers adjacent to travel ways, back walls, and all exposed concrete.
The capital money is obviously not as aggressive in preservation as maintenance money. The capital side probably spends 25 – 30 % of their funds in preservation while the rest is reconstruction and bridge replacement.
Getting the capital people, who focus on new bridge construction, to invest funds on preservation activities has been a major shift in the way Maine DOT operates. It is a combination of preservation, construction and reconstruction that allows maximizing investments for the bridge infrastructure.
What are the key points of the bridge preservation strategy at Maine DOT?
Our main strategy is to keep bridges in good condition by doing preservation activities. We are getting out of the “worst first” type of mentality, even though we continue to take care of bridges that are deteriorated beyond the practical maintenance point.
If you talk with other representatives from the TSP2 Bridge Preservation Partnership, you will find that they are using the same approach.
Do you have any statistics that show the benefits of a bridge preservation strategy?
The benefit of preservation is probably one of the hardest things to capture. For example, when you seal concrete it is hard, almost impossible to predict, whether the concrete is preserved for 20 or 25 years. In terms of NBI Bridge Inspection Ratings, when you seal the concrete of a pier, you do not change the rating of the pier. Let’s say the pier is in a condition state 6. By sealing the concrete you hopefully have kept the pier in that condition state for a longer time, which does not show up in graphs or statistics. It is really difficult to quantify the benefits of preservation actions.
Is it challenging to convince people of the benefits of preservations?
Yes, building a new bridge always carry the headlines. However, the political flavor has changed in Maine and around the Nation. People understand that it is worth preserving bridges, especially when they see the tremendous cost for a new bridge. Spending a fraction of that cost to do actions that can preserve an older bridge and get 30 – 40 more years of life out of it is evidently the proper way to go in most cases.
What are your goals with bridge preservation?
In line with the National Highway System guidelines, our primary goal is to eliminate all condition 4 , corresponding to poor condition, for bridge elements. However, our goal is not only based on numbers but also on a case by case evaluation. Let’s say that we have an abutment that is in a condition state 4. It does not mean that the abutment is unsafe. It just means that the abutment is not in a good condition. It may have been in that condition for 20 years and it may be able to provide another 10-15 years of service life in that condition. Sometimes it is necessary to be aggressive on a bridge element, sometimes not. What is important is to evaluate the impact of the element on the functionality and the safety of the bridge.
Can I say that that you are in favor of a selective approach?
If you just look at numbers, they are pretty sterile; they do not tell you the whole story. It takes skilled, talented, knowledgeable professionals within each State Agency to evaluate risks related to the condition state of bridge elements. To be able to quantify and qualify these risks is a key knowledge that ultimately keeps public safe.
You do not want to spend funds just to make the numbers look good. You want to do the right thing for your bridge inventory. If you can postpone expenditure for 15 years without jeopardizing safety and function, then this is the right thing to do in my opinion.
Who takes decisions related to bridge elements at Maine DOT?
We take decisions in a bridge committee that comprises of three legs: bridge maintenance, bridge design and construction, the so called capital program, and bridge management. It is what we call Maine DOT’s bridge community. We know each other. A lot of us have worked together for as long as 30 years.
I am also part of a posting committee at Maine DOT that takes decisions on bridge weight restrictions. If a bridge does not meet a certain level of capacity based on bridge ratings, we evaluate whether we post the bridge or we strengthen it. In some cases, we do research, such as load testing, cutting coupons out of the steel to see if it is still strong, or cutting reinforcement steel in concrete to see strength can be added.
Some posting can be restrictive thus impacting community and commerce. Bridges in rural areas usually need fewer restrictions since they just carry fire trucks and light vehicles. Even though many bridges in Maine are in good condition, they were designed 60 years ago for a much lighter type of vehicles. Over 50% of Maine bridge inventory is more than 50 years old.
We spoke of the challenge of making people aware of bridge preservation benefits. Are there other major challenges?
The availability of experienced, qualified workers is another major challenge for bridge preservation. Craft people are not readily available as they once were. This challenge is not peculiar to Maine but rather a nationwide issue.
Do you do in-house maintenance work?
Two years ago Maine DOT started contracting maintenance jobs out. We had more money for maintenance than in the past but not enough people to do the job. We therefore decided to contract out using those additional funds. It was a little clunky at first because we had never contracted jobs out before. The capital department had always done all the contracting for bridges at Maine DOT. We had to learn how to put out contracts and they are small contracts, generally under $200,000.
With the increased funding, do you have enough money for all preservation work at Maine DOT?
In 2007 and 2014 we developed two reports called “Keeping our Bridges Safe” (see Linkage – Ed. Note). Those reports recognize the need of spending $140 M/year for bridge preservation. However we get on average $105 M/year. As a result of being we remain $30 – 40 M/year short of spending requirements, at Maine DOT we are accumulating a spending deficit of $90 – 120 M in the length of time of 3-4 years.
Is there any bridge preservation success story you would like to share?
I think our biggest success story is that the entire bridge community at Maine DOT is on board with bridge preservation and really sees the value of it.
Painting may not improve the NHS condition rating of a superstructure, sealing concrete may not improve the NHS condition rating of a substructure; however these are important actions to keep bridges in a good condition. As an analogy, regularly changing the engine oil does not modify the way one drives a car but it makes a big difference in the longevity of the cars’ engine.
Does TSP2 assist you in reaching your bridge preservation goals?
I remember when Ed Welch from New Hampshire DOT, Pete Weykamp from New York DOT and Everett Barnard, my predecessor at Maine DOT, used to meet in New Hampshire with maintenance personnel. These three people first recognized the need for bridge preservation to have its own forum. So my hat goes off to them for pushing the preservation idea and setting up the conditions for having the Partnerships.
To me every year TSP2 Bridge Preservation meetings are better. Communication between bridge preservation practitioners is improving and we have more proficient people representing manufacturers. I can call up a number of engineers that are part of the Partnership and ask: have you tried this? Have you got this problem? What do you do to solve it? The network is just phenomenal.
There is a great value for bridge preservation practitioners to connect with product manufacturers’ people at the TSP2 Bridge Preservation Partnership meetings. Bridge practitioners can speak with different manufacturers and compare their products. There is also an opportunity for competitors to confront their products. Manufactureres also have avenue where they can speak with each other and potentially start collaborations for putting together different products and technologies in order to solve bridge preservation problems. TSP2 sets the stage for creating synergies between product manufacturers.
“Keeping Our Bridges Safe” 2007
“Keeping our Bridges Safe” 2014