Sustainable road pavement

06/09/2017

In 2017, Downer used recycled materials in the production of asphalt and effectively reduced GHG emissions.

Downer has maintained its focus on using materials such as glass and printer cartridge toner to manufacture asphalt, effectively keeping it out of our waste stream.

The use of recycled materials in asphalt manufacturing produced the following results:

• Toner from printer cartridges – a total of 534 tonnes (138 tCO2-e)
• Fly ash (by-product of coal combustion in power stations ) – 1,286 tonnes (598 tCO2-e)
• Glass – 7,116 tonnes (33 tCO2-e)

Across Victoria and New South Wales in our road stabilising works we have been able to substitute resources to reduce GHG emissions by replacing:

• 2,438 tonnes of cement with slag (1,285 tCO2-e)
• 310 tonnes of fly ash replacing lime (275 tCO2-e)

Flexible pavement solutions

Through relationships with customers, suppliers and the broader industry, Downer is constantly innovating to provide the community with flexible pavement solutions, incorporating greater recycled content while achieving an overall lower greenhouse gas footprint.

The culmination of asphalt production technology and the use of waste products has resulted in the development of asphalt made from 99% recycled materials. This world first was achieved with industry partners to pioneer the reuse of waste items such as toner from used printer cartridges, waste oils, post-consumer tyres and glass, which would ordinarily be stockpiled or sent to landfill.

Downer has introduced a Low CO2 Spray Seal containing recycled toner to the market. This new innovative product has the potential to reduce CO2-e emissions by 45kg per tonne of Spray Seal compared to a standard 45R grade binder.

Downer also manufactures high binder emulsions that eliminate the need for cutback and solvents. The high binder emulsions significantly reduce VOC emissions released; they are transported at a much lower temperature and reduce the amount of transport generated greenhouse gases.