Valla Road Nambucca Shire Council AustStab Awards of Excellence 2013 MidCoast Road Services Innovation or Excellence in Stabilisation in Local Government Sponsored by

Valla Road Stabilisation, Nambucca Shire Council The Brief: Fix deteriorating sections of a rural arterial road with a limited budget Minimise disruption to local residents Maximise a safe working environment Remain on an existing timeframe The Team: Noel Chapman – Nambucca Shire Council Ken Hackett – Hackett Geotechnical Laboratories Mark Pilgrim – MidCoast Road Services Ed Hemming – MidCoast Road Services

Valla Road Stabilisation, Nambucca Shire Council The initiative and key points: Excavate the top 200mm of pavement material and stockpile Excavate the bottom 200mm of sub standard in-situ pavement to waste Replace the bottom 200mm with the stockpiled 200mm and stabilise with 70/30 slag/lime blend at 3% Import new material to be compacted and grade to desired level. A methodology had to be adopted to suit poor subgrade conditions:

Valla Road Stabilisation, Nambucca Shire Council Evidence of success: Sustainability – The reuse of existing material reduced the spoil, reduced the volume of imported material and reduced the overall environmental impact due to the reduction in vehicle movements to and from the quarry. Timeframe – The new methodology allowed the contract to run unhindered, no additional machinery or materials were required and delays to the local residents were kept to a minimum. Economical - Significant cost savings were encountered by reusing in-situ material as opposed to the purchase and delivery of new material. Safety – Due to eliminating the need to leave deep excavations open a safer work environment was obtained.

Valla Road Stabilisation, Nambucca Shire Council Results and Supporting Data: Conclusion After nearly 12 months of continuous use the pavement has held up through some exceptional conditions. Severe weather, 250mm of rain in three days and intense trafficking due to Valla Road being used as a detour route for the Pacific Highway have tested the pavement to its limits with no signs of stress or fatigue.