Collaboration turns costly rubble into valuable fill
Rubble from bridge demolition became fill for another bridge
Oregon Department of Transportation contractors recycle 30,000 cubic yards of waste from Interstate 5 bridge demolitions
It’s no small thing to close down a section of Interstate 5.
At about 10 p.m. on June 6, just north of Cottage Grove, Ore., with traffic whizzing by, ODOT contractor crews started to close the northbound lanes of the freeway and detour traffic to Highway 99 North in preparation for demolishing the River Drive overpass. The bridge is one of hundreds being replaced as part of the Oregon Department of Transportation’s OTIA III State Bridge Delivery Program.
By 10:30 p.m., tractors were spreading sand under the overpass to absorb the shock of falling concrete and to protect the freeway. Excavators armed with hydraulic-powered jaws were moving into place, preparing to crush the concrete and rebar that made up the overpass.
By 4:30 a.m., the northbound section of the overpass was history, and its remnants, along with the three feet of shock-absorbing sand, were cleared.
On June 7, the process began again, this time with the southbound section of the overpass slated for elimination. The second night went off without a hitch. When demolition was complete, by 2 a.m., most of the overpass was lying in shambles in the southbound lanes of I-5.
In highway maintenance and bridge replacement, this scene of thousands of cubic yards of construction rubble is a typical one. But this time, the aftermath was different.
On the bridge program, a $1.3 billion investment to repair or replace nearly 300 bridges across the state in 10 years, ODOT’s approach is to choose long-term solutions that take into account the needs of the economy, the community and the environment. With this in mind, the contractor, Holm II Inc., and subcontractor, Goodfellow Bros. Inc., on the Clarks Branch to Tunnel Mill Race project got together with the contractor on a nearby project to save time and money, while also treading lightly on the environment.
Only a short distance from the Clarks Branch to Tunnel Mill Race project, ODOT will replace two I-5 bridges over Hill Creek and two bridges on the Springfield-Creswell Highway outside of Creswell, Ore., as part of the $9 million Oregon Avenue I-5 Overcrossing project.
Ross Bros. & Co., the Salem-based construction contractor managing the Oregon Avenue I-5 Overcrossing project, needed nearly 40,000 cubic yards of embankment materials to use beneath the four bridges and in widening the Springfield-Creswell Highway and I-5 interchange.
Working together, the three independent contractors agreed to exchange the aggregate free of charge. Goodfellow Bros. avoided disposal costs, and Ross Bros. avoided purchasing fill.
Design-build provides contractors with opportunities
for collaboration and creative solutions
When the dust settled, the rubble totaled roughly 30,000 cubic yards of material, but it’s what the contractors did with the demolition waste that makes this project unique.
On a tightly packed construction schedule, collaboration between projects keeps everyone on time and within budget. Through the design-build contracting process, ODOT has committed to giving contractors more responsibility and freedom, which made the exchange between Goodfellow Bros. and Ross Bros. possible.
Design-build contracting is becoming widely used around the country. Many transportation programs have added design-build capabilities in the past 15 years. The process gives contractors the latitude to propose creative solutions that may address current needs, future needs or both.
“Being able to work on design-build projects is a treat,” said Satarri Tofte, Goodfellow Bros.’ bridge program project manager. “With design-build, there’s more incentive to save money, which all contractors like, and to make creative arrangements like this one with Ross Bros.”
Reusing rubble is cost effective and eco-sensitive
While recycling is good policy, reuse is even better. As soon as the demolition was through, the recycling process began. Goodfellow Bros. crew members were able to clean and crush the concrete themselves, because they have all of the necessary equipment. They broke the concrete chunks into manageable sections and stripped the rebar with an excavator. Before the rubble from the River Drive overpass was transported to its new home at the Oregon Avenue I-5 Overcrossing project, Goodfellow Bros. ran rollers over it to break the aggregate into small, uniform pieces.
If the companies hadn’t arranged to exchange materials, the waste would have been transported to a paving or rock-crushing facility for disposal, where a third party would strip the rebar and crush the concrete to be resold as aggregate. Goodfellow Bros. avoided nearly all of the cost of this process, typically $9 per cubic yard including transportation.
“To conserve resources is one benefit of recycling,” Tofte said. “But the largest benefit for us is that it’s cost effective. Keeping materials out of landfills or alternate disposal sites is just a big bonus.”
Goodfellow Bros. went beyond reusing the rubble as aggregate and recycled the steel from demolitions at the Clarks Branch to Tunnel Mill Race project as well. Oregon-based Schnitzer Steel Industries, one of the nation’s largest recyclers of ferrous metal, provided drop boxes at the demolition site for Goodfellow Bros. to fill with rebar. When the clean-up process was complete, Schnitzer Steel picked up the boxes and paid Goodfellow Bros. for the metal.
The exchange of materials produced other economic and environmental dividends. In addition to keeping the rubble out of a landfill, Goodfellow Bros. and Ross Bros. also saved money on transportation costs. Because the two work sites are less than two miles apart, fuel costs and pollution were vastly decreased.
ODOT saves money through this initiative as well. Every construction contract has a clause that allows for rising fuel prices. Reusing the waste material and transporting it over a shorter distance lowered the amount of money spent on gas, making the contract price more stable and helping ODOT stay under budget.
“Before any construction begins on the bridge program, we hold a preconstruction briefing with our partners to set goals on efficiency and cost reduction,” said Brent Pierson, resident construction manager with Oregon Bridge Delivery Partners, the private company hired by ODOT to help manage the bridge program. “We encourage all of our contractors to find ways of working more efficiently. Recycling the waste material from one project for use on another is a great of example of quick thinking and cooperation to save time and money.”