Viable opportunities in viaduct recycling

by guest blogger Noel Brady

This chunk of the Viaduct showed up on Ebay
Turns out there’s more than one way to recycle a 60-year-old viaduct.

When we razed the southern portion of the Alaskan Way Viaduct in late October, several shrewd spectators turned to eBay to recycle their pieces of Seattle history into cold hard cash. One chunk of concrete went for at least $16.50, minus shipping.

WSDOT and viaduct contractor Seattle Tunnel Partners (STP) saw opportunity in recycling too; they turned viaduct rubble into cold hard building materials. Our transportation engineer Amjad Omar said nearly 100 percent of the old concrete and rebar from this portion of the viaduct in Seattle will be recycled and reused.

From October’s demolition alone – about 25 percent of the total viaduct structure – crews hauled 3,500 truckloads of concrete rubble to Terminal 25. There, the concrete was crushed to be reused for the new SR 99 Tunnel that will replace the viaduct, and the rebar is being prepared for transfer to a local recycler.

Not only does recycling save us on the cost of materials, but it also reduces greenhouse gas emissions from hauling rumble to a far-off disposal site, producing new materials and hauling it to the work site. Recycling old bridges and other transportation structure is nothing new for us. Last spring we recycled 100 percent of the NE 12th Street Bridge that spanned I-405 in Bellevue.

The state does not require recycling in bridge demolition, but it is becoming the norm as the market for recycled materials grows. Our engineers routinely write construction specifications to ease the future recycling of materials.