Infrastructure protectionUMaine student develops affordable option for shoring up Maine’s aging bridges
The State of Maine Department of Transportation is responsible for 2,772, or 70 percent, of the bridges in the state. A 2007 report found that of those bridges, 205 are more than 80 years old, 244 were considered in poor condition, and 213 were found to be structurally deficient. Additionally, 288 bridges were at risk of closure or weight restrictions between 2007 and 2017. Replacing all these bridges would be too costly. Researchers developed software designed specifically to assess the load rating of flat-slab bridges to determine which bridges can be repaired instead of replaced. For the bridges that can last a few more years with reinforcing instead of replacing, the researchers engineered a retrofitting system which could be applied to increase the bridge’s strength and weight limits.
Real-time monitoring will allow repairs before the defect becomes a danger // Source: http://www.newsdesk.umd.edu/mail/send.cfm?articleID=2745
Last month, Maine was ranked ninth in the nation for percentage of bridges classified as deficient in a report by the Washington, D.C.-based Transportation for America. The report used Federal Highway Administration data to determine nearly 15 percent of Maine’s bridges require maintenance or replacement.
Replacing, and even rehabilitating, all of the bridges at once is a large financial burden for the Maine Department of Transportation. Hannah Breton Loring, a University of Maine graduate student in the Department of Civil and Environmental Engineering from Greenville, Maine, hopes to ease that burden by offering the MaineDOT a more affordable bridge retrofitting system than the current commercial options.
A University of Maine release reports that Loring’s system, engineered and tested at UMaine’s Advanced Structures and Composites Center, is a fiber-reinforced polymer flexural retrofit system made of carbon composites and glass to reinforce and strengthen concrete flat-slab bridges, many of which are fifty or more years old.
“There are multiple reports and report cards on bridge infrastructure, and the U.S. is doing very poorly,” Loring says. “What we’re trying to do is give Maine a little bit of a stepladder. We’re giving them a low-cost alternative for the short term that would increase the strength and durability of the bridge, prevent it from having to be weight posted, and allow the bridge to remain safe.”
The 2007 collapse of the I-35 Mississippi River bridge in Minneapolis, Minnesota, which killed thirteen people and injured 145, served as a wake-up call across the nation, urging transportation departments to look at the condition of their own bridges, according to Loring.
After the collapse, the MaineDOT formed a panel to review its bridge inspection and improvement programs. Engineers on the panel, from the MaineDOT, UMaine, and private consulting and construction sectors, released the report Keeping our Bridges Safe in November 2007.
According to the report, the MaineDOT is responsible for 2,772, or 70 percent, of the known bridges in the state. Of those bridges, 205 are more than 80 years old, 244 were considered in poor condition, and 213 were found to be structurally deficient. The report also estimated that 288 bridges were at risk of closure or weight restrictions between 2007 and 2017.
“A lot of these bridges have to be replaced or extensively repaired, so that’s asking for a lot of money from the Maine department and we’re already struggling,” Loring says. “If we
