Hunter Quarries delivered 95,000 tonnes of MB20 for a major infrastructure upgrade.
John Holland Gamuda
Civil Infrastructure
Tomago
MB20
For Hunter Quarries, it meant precision at every stage — from specification and approval through to production, quality control, and delivery.
In mid-2024, we were engaged by John Holland to supply MB20, a modified granular base material used in heavily bound pavement layers, for a major road infrastructure project. MB20 is produced in accordance with TfNSW R73 and is designed for high-stress road construction applications.
Our nominated grading was submitted in July and, following rigorous testing and review, was approved by John Holland. Key RFIs confirmed the material’s stability:
A process audit conducted on site by John Holland in September returned zero non-conformances, confirming the robustness of our systems and procedures.
MB20 supply commenced in late August/early September. To support clear communication and improve stockpile management, we implemented an updated bin system:
Throughout the supply period, not a single Non-Conformance Report (NCR) or Quality Improvement Process (QIP) was raised — a strong result that reflects our consistent commitment to quality and compliance.
Delivering high-volume material to tight specifications came with its challenges. Each 4,000-tonne lot was tested to ensure it remained within the nominated grading range. At the same time, we closely monitored the Plasticity Index to meet the 0–2% MB20 requirement, all while continuing to produce and deliver other aggregate products.
Weather was another factor. Several significant rain events impacted production and delivery timelines — but through careful planning and communication, delays were managed and the program stayed on track.
Across every stage of this supply — testing, production, delivery, and performance — our team maintained focus and flexibility to deliver what was needed. With zero NCRs and strong audit results, this project reflects the quality standards we aim to meet across all major infrastructure supply partnerships.
Contact our specialised team for more information about our products and how we can meet your specifications.
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