New service center uses power plant ash for EcoPad

Our new service center in Menomonee Falls not only offers a larger, more efficient space for employees to work but also models our commitment to environmental stewardship.

Many eco-friendly features are included in the new structure, which opened last year. One of those features is the EcoPad that serves as the pavement surface in the facility’s yard area where heavy materials are stocked. An EcoPad is concrete pavement composed of power plant bottom ash, recycled concrete and a fly ash-plus-Portland-cement mix. These ingredients are mixed on the ground surface with a special piece of equipment used in pavement recycling. The bottom ash and fly ash ingredients came from our own power plants. The EcoPad uses 92 percent recycled content.

Fly ash from Oak Creek Power Plant was used as a binder or “glue” along with Portland cement, and 270 tons of bottom ash from the Oak Creek Expansion units was used as a fine aggregate. Recycled concrete from a local pavement recycling plant near Menomonee Falls completed the mixture.

The EcoPad is suited for the stockyard area where equipment, cable spools, transformers and other heavy items might damage or penetrate ordinary asphalt. The EcoPad's high strength can withstand 4,000 pounds of weight per square inch, which is better durability and service than asphalt provides. The surface of an EcoPad has the look of exposed aggregate -- rustic and durable.

Bottom ash is a sand-like material collected at the bottom of coal-fired boilers, which is marketed as a base construction material for roads, parking lots, buildings and as a trench backfill. Bottom ash replaces conventional sand, avoiding sand mining and use. In addition to the EcoPad, more than 6,000 tons of bottom ash were used as a base for road and parking lot paving at the service center.

Bottom ash from the Pleasant Prairie and Oak Creek power plants has been used extensively in construction projects throughout the greater Milwaukee, Racine and Kenosha areas, including:

• I-94 reconstruction project in southeastern Wisconsin. 
• Large warehousing facilities for building foundations, roads and parking lots. 
• Utility trench backfills. 

These projects, among many others, have used several hundred thousand tons of bottom ash over the past 10 years.

The following 10-minute video details and demonstrates EcoPad: