Bridge deck life extension comes with hefty price tag

MT. PLEASANT — During a regularly scheduled roads update with the Henry County Board of Supervisors the morning of Tuesday, Aug. 8, County Engineer Jake Hotchkiss presented a plan to lengthen the life of a county bring by an anticipated 10 years with epoxy injections.

The Henry County Roads Department intends to rent equipment for epoxy injection from Buchanan County for $350 per day with an expectation that the project will take two days. If the project takes additional time that rental price will increase to $1,000 for a week.

This rental agreement, which the Board of Supervisors approved, also states that Henry County will pay for materials such as epoxy and tubes used in the process.

Additionally, the roads department will hire a contractor with expertise in the epoxy injection process to operate the equipment.

According to Hotchkiss, this contractor’s expertise comes with a hefty price tag of $12,000 and the project overall should cost between $18-19,000.

“I think the big thing I would tell you is we're really paying for his expertise,” Hotchkiss said.

“The biggest concern is, obviously, is that if you put too much pressure on it, you'll pop the deck and get a bigger problem,” He explained. “What would end up happening if you had a section that would get too much pressure, then he'd be doing a deck patch or concrete patch right there.”

In addition, Hotchkiss encouraged the supervisors to think of the overall price in terms of the extended life of the bridge deck.

“If you think about the 10 year extension, that's pretty cheap,” he said.

“It sounds high,” Hotchkiss said. “That’s why we’re going to put one of our guys out there to see what it looks like and what the process is.”

After seeing the process, Hotchkiss plans to discuss with his crew the possibility of training someone from the county in the epoxy injections so they can avoid the additional cost of the expert services if they repeat the process on other bridges in the future.

According to Hotchkiss, there are five or six other bridges that could possibly benefit from this operation down the line, but the department will need to weigh many factors when deciding if training a county employee is the right approach for future endeavors.

The work is currently scheduled for Thursday and Friday next week on a bridge located on County Highway J20 east of Lexington Avenue.

“The State of Iowa has done a lot of this now on their bridge decks,” Hotchkiss said. “The DOT is a big proponent of it.”

According to a 2019 report about deck epoxy injections from Iowa State University’s Institute for Transportation, “Since the 1970s, the Iowa DOT has used concrete overlays as a means of restoring its bridge decks and, as a result, the service life of the deck is commonly extended many years. This procedure has proven to be both effective and economically attractive.”

However, according to the report, these concrete overlays are not considered permanent repairs due to harsh conditions.

“As time passes, the overlays often become delaminated from the original deck at or near the bond interface, leading to cracking and the intrusion of water and chloride ions, which accelerate the deterioration,” the report states. “A preservation solution involving the injection of epoxy resin into the cracks and voids has been developed and this solution has been implemented with success across Iowa.”

According to Hotchkiss, “A lot of counties are coming on board now where we’re starting to do this to extend those existing deck overlay lives.”

Comments: AnnaMarie.Ward@southeastiowaunion.com