ECO5 – Paving at Port Stephens

CNS recently won a tender to supply and pave ECO5 as a wearing course on a local road in Port Stephens Council. The Council wanted to conduct a demonstration trial to compare the performance of a standard AC14 against a lower carbon equivalent asphalt mix. On the night of 21 June the Tomago plant manufactured 417 tonnes of ECO5 (14mm) which consisted of:

• 2.5% recycled crushed glass (RCG) as a sand replacement
• 20% RAP as a binder and aggregate replacement
• A15E binder with 10% crumb rubber as a bitumen and polymer replacement

The A15E was produced at SAMI’s Camellia plant for the first time using crumb rubber and was modified with a lower melting point synthetic wax. This allowed the ECO5 mix to be produced at 160⁰C and paved below 135⁰C without generating any fumes or odours. The manufacture of A15E with crumb rubber now paves the way for CNS to be able to register ECO5 with TfNSW under the R116 specification for heavy duty asphalt pavements using 10% RAP as a wearing course.

What got CNS across the line with winning this contract was that we were able to demonstrate to the Council that ECO5 would:

• Reduce CO2e by 8,865 kg compared to standard AC14 for the project. This is a savings of 33% in the carbon footprint in production of the asphalt using the values in the AfPA calculator.
• Recycle 10.4 tonnes of RCG which equates to 57,917 empty stubbies.
• Recycle 4.17 tonnes of crumb rubber which equates to 758 end-of-life tyres
• Recycle of 20% RAP

The use of the above repurposed waste materials equates to the following savings in the use of non-renewable raw materials:

• 8.8 tonnes of bitumen
• 78.8 tonnes of crushed aggregates
• 10.4 tonnes of natural sand

Furthermore the lab performance tests previously conducted on ECO5 showed that you can expect an increase in the rutting and crack resistance of ECO5 compared to the virgin AC14 which will improve the Life Cycle Inventories of asphalt.