QTMR awarded COLAS QLD the largest project undertaken to date in Australia where Gap Graded Asphalt and Open Graded Asphalt produced with CR1 binder has been utilised. The works were undertaken on the Nambour Connection Road and Emu Mountain Road about 100km north of Brisbane from August to November this year. In total 2,743 tonnes of OGA and 16, 372 tonnes of GGA were paved. The mixes were produced at the Caloundra asphalt plant and the CR1 was blended at SAMI’s Pinkenba PMB plant.
What makes this project special is that the binder was blended using 18% crumb rubber derived from end-of-life truck tyres. The CR1 binder was modified with a special warm mix additive so that the asphalt mixes could be produced at temperatures below 165⁰C to reduce fuming. Due to the highly viscous nature of crumb rubber modified binder, the binder content of these mixes has been increased which will result in more durable and long-lasting wearing courses. In total over 55,000 end-of-life equivalent passenger tyres were used to produce the CR1 binder and saved from going to landfill. This project is a good example of using recycled waste to improve the performance of asphalt without causing harm to our workers and providing a more sustainable pavement solution for the asset owner.