A concrete plan

When a building undergoes major renovation, the amount of debris from the project can quickly pile up. Those who oversee the project have two options: landfill the construction and demolition (C&D) debris or recycle it. Volkswagen, with U.S. offices in Herndon, Virginia, went with the latter option during renovations of its Chattanooga, Tennessee, assembly plant.

“Volkswagen was faced with the possibility of creating a substantial amount of waste with concrete excavated during the expansions,” Keith King, Volkswagen Chattanooga’s communications specialist, says. “At the same time, the expansion project required a lot of gravel subbase for building expansion, new concrete parking areas and access/security roads.”

King says the Volkswagen Chattanooga construction and environmental teams decided to recycle the concrete because of the large quantity of debris and the need for gravel and concrete roadways.

“The cost and environmental impact of hauling and landfilling the concrete was avoided, and the team was able to recycle and reuse the material around the facility,” King says.

CONCRETE CONSCIOUSNESS

The $1 billion assembly plant began production in April 2011. At the facility, 3,500 team members manufacture the Passat midsize sedan. In late 2011, the plant received Platinum certification through the U.S. Green Building Council’s (USGBC’s) Leadership in Energy and Environmental Design (LEED) certification system.

In May 2017, the company began selling its midsize SUV, the Atlas, and needed to expand the facility to support its production. King says more than 400 robots, along with additional staging space, were added in the plant’s body shop. Existing assembly lines were expanded in the assembly shop and a second line was added to the paint shop.

Overall, the facility expansion was an additional $900 million investment by Volkswagen. The project was completed in two phases, with the body assembly tech expansion taking place from January 2015 to November 2015, and the east warehouse expansion taking place March 2015 to June 2016. The project took around a year and a half total to complete.

King says the company did not pursue LEED certification with the expansion.

Gray Construction, Lexington, Kentucky, and the Weitz Co., Des Moines, Iowa, excavated nearly 37,000 tons of concrete from the site. Recycling this material potentially preserved more than 18,300 cubic yards of landfill space. The concrete was hauled to an on-site crusher and processed into various sizes. Seventy-five percent of the material was used as beds for roll-compacted concrete parking and roadways, while the remaining 25 percent was used for gravel patrol roads, walking paths, landscaping and erosion control.

Construction lumber was reclaimed and used to build frames to hold parts.

CRUSHIN’ IT

The construction companies tapped into two different crushing companies to crush concrete for each phase of the project. Wright Bros., Charleston, Tennessee, handled the first phase of the project, while Graham & Turner, Cartersville, Georgia, worked on the second phase.

Graham & Turner has been in business since 1991 and is a sister company of Rockmonster.US’ demolition and crushing operations. Graham & Turner has approximately 25 to 30 employees and, on average, works on about 30 projects per year. “Some are smaller, and we can do more, and some are bigger, so it takes a few extra months to do them,” Mike Turner, owner of Graham & Turner, says.

The Volkswagen project was not the company’s first car assembly plant project. Turner says it also worked on the Mitsubishi plant in Savannah, Georgia, around three or four years ago and on an old General Motors plant in Georgia.

Turner says Volkswagen had three bids on the project and Graham & Turner was its third choice. Regarding how the company found out about Graham & Turner, he says someone referred the automaker to the company.

The Graham & Turner crew would arrive on-site after crews from Gray and Weitz left. Turner calls the job “simple.” He adds, “They had it stockpiled and set up for us to crush it and had a designated site where they wanted us to put it.”

On-site crews separated the steel from the concrete before processing it. Turner’s crew used crushing and screening equipment from Terex Powerscreen, Tyrone County, Ireland, to get the rock down to a No. 57 stone, which is usually crushed to ¾ inches. Turner says Volkswagen used the crushed concrete to fix the roadways. Once crushed, Turner’s crews left the material at designated sites, and Gray and Weitz crews came back in to use it.

On average, Turner says his crew crushed 1,000 to 1,200 tons of concrete per day over three weeks. His crews loaded the steel in a dumpster, and Volkswagen shipped it off-site for recycling.

While Volkswagen decided not to pursue LEED certification with this expansion, King says the company still takes pride in its decision to recycle material. In November 2017, the assembly plant received the Outstanding Achievement in Solid Waste Management award at the Tennessee Chamber of Commerce and Industry’s 35th Annual Environmental and Energy Awards.

“We are very proud of the environmentally friendly initiatives that went into the building process of our expansion, such as the rock crushing project,” King says. “When Volkswagen Chattanooga was built, Volkswagen used the LEED certification process as a guideline for excellence in green building. We take a lot of pride in the Platinum certification the building of the plant received.”

The author is assistant editor of Construction & Demolition Recycling and can be reached at hcrisan@gie.net.