Better Bridges: Bridge Inventory 2009 State of Bridges

Because structurally deficient bridges can also be a safety concern to the public, Indiana DOT’s Dittrich says, highway agencies, the media and political people have keyed in on that term, “structurally deficient.” But that is not where the money is being spent. “We’re spending a ton of money on adding capacity, but not addressing structurally deficient the way we should. Many of our existing bridges are reaching the point where they are now becoming structurally deficient.,” he says.

Bridges can be neglected for a while and their condition won’t change a great deal. But all of a sudden, Dittrich says, “there will be a whole lot of structurally deficient bridges and there just isn’t the money to address them all at once.”

The training and retention predicament

Training and retention is a major concern when it comes to bridge inspection and repair. It’s no secret that the construction industry faces a shortage of qualified workers, and it carries over into bridge repair and inspection. “Bridge inspectors aren’t given the respect they should be,” Dittrich says, adding that a mindset exists that “anyone can do the work.” But it’s to the contrary. “The qualifications keep increasing,” Dittrich says, “and you need training.” He likens it to an untrained paramedic showing up to an emergency scene. “You don’t want to have a guy to show up in an ambulance who hasn’t had CPR training in 10 years,” Dittrich notes. “Half of my inspectors aren’t engineers, but they are expected to know things an engineer would know…and we don’t have adequate funds for training and travel to training. If I can’t keep them up to date, how can they be expected to see the problems they need to see? Or, they may see them [problems] but not understand what is significant and what isn’t.”

The growth of virtual training tool such as Webinars has helped somewhat with the lack of funds for training. However, when there are a limited number of inspectors this training takes time away from fieldwork regardless whether it’s on a computer or in person traveling to a training site. Dittrich points out that one of his inspectors just completed a Webinar on gusset plates but that employee said he ended up working for what seemed like 24 hours if he counted in virtual training and completing paperwork on bridge inspection reports. “You can inspect all you want, but it doesn’t do any good if you don’t have enough personnel or enough funding to address the problems that are found,” Dittrich said. There is enough work to keep his inspectors busy all the time, he says, but it’s still a major problem if they aren’t properly trained or if there aren’t enough of them to get the job done and done well. “Not having enough personnel is our No. 1 problem. The work keeps increasing therefore everyone has to do more.”

Though Congress and the Federal Highway Administration (FHWA) approved funds in the last highway bill — SAFETEA-LU — that were to be used for training and development and would cover travel, per diem, etc., the money ultimately comes off the top of the money a state gets for its bridge program, Dittrich says. “We’re caught in a situation. The federal government and Congress said, ‘We made money available,’ but the states need money for construction. That means we don’t have money to give to the guys for training. I think every state has this kind of issue. The regular money we get, we use the best we can. But we aren’t necessarily being effective with getting the structurally deficient bridges taken care of.”

Dittrich says to address the need for better training, his state inspectors have peer group meetings 4 to 6 times a year. Bridge inspectors from throughout the state get together to talk about ideas, inspection and repair methods that have and have not worked, creating a forum to share knowledge.

“Nothing frustrates a bridge inspector more than to see something that’s fixed and have it fail again in five years,” Dittrich says. “If you put a new deck down and it’s not cured properly, then it cracks, salt gets in, and it deteriorates. But decks and concrete can be made and cured right. It all starts with the mix and rebar…knowing where to stop the rebar.”

This is where the training comes in, Dittrich points out, because it can mean the difference between a bridge that lasts and a bridge that falls into disrepair before its time. “If you jackhammer off all the bad concrete, , you still have good with chlorides in it,” he points out. “You’ll have new concrete with no chlorides next to old concrete with chlorides. This difference in chloride concentration will set up a battery cell which will accelerate the corrosion of the rebars in the vicinity. Therefore testing should be conducted prior to making repairs to see if the choride levels are low enough to use zinc anodes, or if more advanced cathodic protection is required.

“That means you need to have a corrosion specialist go through it,” Dittrich points out. “But this is all new stuff — it’s not done on a widespread basis. We’d love to have our maintenance people be able to do this when they make a patch because they fix an area…when they come back a year later, it’s worse than ever. It all comes back to training, so when they start [on a project], they [know how to] do it right so it will last.”

Environmental challenges

Environmental restrictions continue to affect how well states and municipalities can replace and repair deficient bridges. These restrictions often slow down the process of repairing and replacing bridges, and sometimes, a less-appropriate structure type is used to replace the bridge, KDOT’s Jones notes. This just exacerbates the problem of structurally deficient bridges because more appropriate materials that would keep a bridge in better condition longer are not used.

“When a small span structure can efficiently be replaced with a standard box culvert, the environmental regulatory agencies providing oversight feel that culvert floor is considered ‘loss of stream length’ and has to be mitigated,” Jones points out. “Also, if there are threatened or endangered species present or perceived to be present, that also has to be mitigated.”

The process for reviewing this is complicated by the wide variations in what is considered “acceptable,” even to the point that it depends on who in the various agencies is conducting the review, he says.

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