Innovative OGA Cleaning Process Receives Interim Certification

NTRO is pleased to announce that RETEX Pavement Services has received Interim Certification for its ultra high-pressure cleaning process for Open Graded Asphalt (OGA).

OGA is a road surface designed with interconnected air voids that allow water to drain through the pavement rather than run across its surface. This design reduces surface water spray, prevents aquaplaning and decreases tyre noise making OGA particularly valuable for urban freeways and high-speed roads.

Over time, these air voids become blocked with fine particles, dust and organic matter carried by traffic and weather. As voids fill, the pavement loses its ability to drain water effectively, potentially resulting in increased vehicle spray, reduced permeability, and decreased skid resistance. Cleaning can restore performance and extend asset life.

RETEX's computer-controlled cleaning process uses a specialised vehicle with integrated water blasting and high-volume vacuum systems to remove detritus from the surface and air voids, restoring it to its original design.

Managing Director, Jason Goff advised, “Critical to the process is having equipment with sufficient capacity to flood the OGA matrix with water under moderate pressure. This coupled with the very high-volume vacuum, draws the softened and loosened waste material from the pores of the asphalt. We are very confident in our process and equipment, from years of experience in the industry on this and kindred applications, such as cleaning of flushed spray seals and rubber deposits from airport runways.”

NTRO's Product Evaluation Panel (PEP) conducted a comprehensive assessment including technical literature review, international case study research, and received data from a field trial on the Beech Road Exit Ramp of Sydney's M7 Motorway. This Interim Certification validates that the process shows great promise for the Australian road sector, with a further quantitative trial planned for early 2026.

Alan Hay, NTRO Certification Governance Manager praised RETEX for their positive, professional attitude throughout. “RETEX clearly know their process inside out and have invested in state-of-the-art equipment and monitoring systems to ensure that controls are in place to secure an optimum outcome – a clean, restored OGA matrix without damage.”

The further field observation will include a regime of ‘before and after’ measurement of permeability, skid resistance and surface texture set by the NTRO PEP.  

About NTRO Certification

NTRO Certification provides independent evaluation of innovative transport infrastructure products and processes through a rigorous, transparent framework. The certification pathway gives innovators a credible route to technical acceptance while providing government agencies and industry with the technical validation needed to confidently adopt new solutions. By bridging the gap between innovation and implementation, NTRO Certification accelerates the adoption of products that deliver performance, safety, and sustainability outcomes for Australia's transport sector.

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