Thermopolis Bridge Over Bighorn River Covered With 1.2M Pounds Of Concrete

There was a rush of activity on either side of the Broadway Bridge over the Bighorn River in Thermopolis on Thursday. 

Canyon Concrete had to pour 300 cubic yards of concrete — which is about 1.2 million pounds worth — and they only had one day to do it.

“We’ve had our guys here since 3:30 a.m., ready to pour,” said Cindy Glasson, safety coordinator for Canyon Concrete. “These kinds of pours are not unusual for us, but this is a large pour, and it takes a lot of coordination to get it done.”

Pouring 300 yards of concrete is an immense undertaking, and this one had to be done as a single pour. That means everyone involved doesn't stop until it's done.

“If they have to be out there under lights, they’ll do it,” Glasson said. “They will be finished with it today, no matter how long it takes.”

There is still be a lot of work to complete before the project's finished. Wyoming Department of Transportation (WYDOT) spokesperson Cody Beers said everything’s on track for this vital link in Thermopolis to be open to traffic before the end of October.

“It’s basically a brand-new bridge,” he said. “It receives tons of traffic every year, and it needs improvements. Now, it’ll last for another 50 years.”

Cracked Concrete

The Broadway Bridge has been closed since early July when S&S Builders of Gillette started the $2.19 million project of much-needed repairs.

WYDOT awarded S&S the contract in February. It was tasked with removing and replacing the bridge deck, performing substructure repairs and painting, replacing the approach slab, repairing the sidewalk, replacing the bridge rail, and paving the approach.

“S&S does good work,” Beers said. “It’s a big job, and we’re proud of what they’ve done.”

Thermopolis’s Canyon Concrete was hired to do the concrete pour across the bridge, which Beers said was badly needed.

“The concrete portion of the bridge had holes in it and was falling apart,” he said. “The steel and iron underneath the bridge was fine. The contractor did some work just to clear up rust and things like that under the bridge. 

"But that part of the bridge was just fine. We just needed a new concrete deck.”

The bridge is a critical piece of infrastructure for Thermopolis. Not only is it the main way to get over the Bighorn River, it’s also the primary route that ambulances take to reach Hot Springs County Memorial Hospital.

Traffic has been rerouted through Hot Springs State Park since the bridge closed, but that presents its own problem. 

Glasson and many other Thermopolis residents have been eager to get the Broadway Bridge reopened as soon as possible.

“The other route over the river has a 12-foot underpass into the park,” Glasson said. “RVs have gotten stuck underneath there for years because they’re too tall to get through. We're definitely going to be glad to have this bridge back in service.”

'Coordinated Chaos'

Canyon Concrete has been ready for the 300-yard pour for the last three weeks, waiting for S&S Builders’ construction crew to give them the go-ahead. Glasson described the process as “coordinated chaos.”

“We rearranged everything in our yard so that we were able to clean out each truck, back it into the batch, fill the truck, and head straight down to the bridge,” she said. “We’re only five blocks from the bridge, so everything's getting there fresh. 

"It doesn’t have to travel 20 or 30 miles to get there, so they're constantly running trucks through here.”

A typical concrete truck can carry 8 to 10 cubic yards of concrete. Pouring 300 yards in one day requires at least 30 truckloads, with trucks going back for new loads as soon as they’re empty.

Extra concrete trucks were brought in from Cody and Powell to ensure a constant flow of fresh material was available. 

Glasson said S&S provided a special tool for the job: two concrete pumpers, one on either side, to pour concrete from both ends of the bridge simultaneously.

“We pour concrete from the top and it comes down through a large hose at the bottom of the pump,” she said. “A gentleman at the bottom moves it back and forth within the frame to get the right amount of concrete in each section.”  

After the concrete is poured, a screed is used to level it while it’s still wet. However, the screed is attached to the machinery, saving a lot of time and labor.

With pumps and screeds at both ends, Canyon Concrete was able to cover the 300-yard expanse as a single pour. That’s critical to the structural integrity of the bridge once the concrete dries.

“The bed has to be a single pour, and that’s a very large pour,” Glasson said. “They go along as each section is poured and flatten it out so that everything is level. It’s really cool to watch.”

Core Check

There’s a critical step that needs to happen before a loaded concrete truck departs Canyon Concrete. Glasson said a core sample has to be taken from every truck before it’s cleared to reach the bridge and pour.

“The best way I can describe it is that it’s like a recipe,” she said. “Different additives have to be put in the concrete to meet (WYDOT’s) expectations for road work, so we have to use that specific recipe in order to create the concrete that they need.”

Core samples help determine the concrete’s consistency. Too much or too little water can throw everything off, so no trucks leave the yard unless their core samples are exactly what they need to be.

“By checking every single truck that comes out of here, they know it's all going to be up to the exact same specifications,” Glasson said.

Almost There, Thermopolites

The concrete pour on the Broadway Bridge will be completed in one stroke, regardless of the time it takes. After that, there’s still work that needs to be done before the bridge reopens.

“There's a lot of work still to be done after the concrete pour,” Beers said. “They’ve to put up the guardrail on each end of the bridge and do the new approach slabs on either side. As long as the weather maintains, we’re optimistic that the bridge will be open somewhere around mid- to late October.”

WYDOT originally announced the closure would lift Oct. 16. Glasson wouldn’t be surprised if the closure was extended slightly, based on changes to Canyon Concrete’s schedule.

Canyon Concrete has been doing large-scale concrete pours for more than 40 years. Construction delays are unfortunate, but they’re expected.

“We were supposed to pour last Friday, but they put us off until today,” she said. “We’ve been preparing for this pour for the last two or three weeks, so we knew it was coming. We weren't exactly sure what day it was going to be, so we were ready when the day came.”

Beers said the project as a “win-win” for Thermopolis and East Thermopolis. In addition to getting the lifespan of the important bridge extended for several decades, the monthslong project has brought a lot of economic activity to the communities.

“Those workers have been staying in Thermopolis for about three months, and they’ve got another month to go,” he said. “During that time, they’ve been eating meals, renting rooms, spending money in that community, and people have been able to benefit from the contractor being there.”

The concrete pumps have been a tremendous asset in completing the massive concrete pour. Glasson said everyone’s working as efficiently as possible to reopen the Broadway Bridge while ensuring the work meets the highest standards.

“Rather than having to have a group of men on their hands and knees, like they would do with a driveway or sidewalk, these machines do everything all at once,” she said. “It makes it so much easier.”

Andrew Rossi can be reached at arossi@cowboystatedaily.com.