The Kelley Road bridge in Orono that passes above Interstate 95 is in for a makeover as it prepares for its seventh decade.
Chlorinated water seeps through the 58-year-old bridge joints down onto the load-bearing columns, and crews have to continuously prevent loose concrete pieces of the bridge underbelly from crashing down onto the highway below.
The leaky joints and flaking substructure have led the Maine Department of Transportation to consider putting a partial reconstruction of the bridge on its agenda for 2020.
At a workshop in Orono on Wednesday, the department presented preliminary construction plans to the public.
“This is early in the engineering process,” Ted Talbot, a department spokesman, wrote in an email. “The scope will be further defined as we investigate alternatives.”
As it stands now, the project will include a replacement of the bridge surface and some rehabilitation of the support structure. The department also plans to replace the bridge rail, joints and pavement.
An alternative to joints may be a link slab design, which relies on larger segments of pavement joining portions of the bridge together instead of narrower metal joints. Bridge design experts generally credit the design with reducing maintenance.
The department presented two construction options at the meeting: Building the bridge deck in halves and keeping traffic open on the other side, or closing the bridge altogether and detouring traffic onto other state-maintained roads. The first option would take at least one full construction season, beginning in the spring and lasting into October or November, according to the Department of Transportation. The second option would take less time, and the department would limit the major traffic disruption to the school summer vacation months when nearby University of Maine isn’t in session.
“The reduced construction duration appealed to most people at the public meeting and was reflected in their feedback after the presentation,” Talbot said.
The current estimate for the project is $2.53 million, but that may change as detailed designs and public feedback are incorporated into the final plans.
The bridge’s substructure last underwent repairs in 2009, according to the Department of Transportation.