Aurizon Network FY26 Bridges and Culverts Maintenance Program
Comprehensive maintenance program across 20+ culvert and bridge sites for Aurizon Network Queensland coal rail network. Delivered concrete spall and crack repairs, corrugated metal pipe corrosion protection, pipe replacement, and protective infrastructure installation across multiple rail corridors.
Challenge
Aurizon Network required comprehensive maintenance across 20+ geographically dispersed sites along Queensland coal rail corridors addressing deteriorating bridge and culvert infrastructure critical to network operations. The scope encompassed diverse defects including severe concrete spalling with exposed reinforcement requiring rust treatment and structural repair mortar application, concrete cracks ranging from 0.3mm to 6mm requiring epoxy injection to prevent water ingress and further deterioration, extensive corrosion in corrugated metal pipe culverts requiring full abrasive blasting and three-coat protective painting systems, collapsed CMP requiring insertion of 1300mm liner pipes within existing 1800mm pipes with annular void grouting, and installation of protective bollards preventing vehicle damage to critical drainage infrastructure. Work at Site 7 Aroona-Duaringa revealed 38 severe defects beyond original scope during site inspections, while Site 8 Grantleigh-Tunnel presented failed previous repairs with additional cracking since original intervention. All works required coordination with active coal network train movements, community engagement for works outside rail boundary at Gregory-Oaky Creek, and practical completion by December 2025 to meet FY26 maintenance programme milestones.
Solution
Sterling Infrastructure deployed specialised bridges and culverts maintenance teams with expertise in concrete repair systems and protective coatings. Concrete spall repairs employed controlled saw-cutting establishing defined 10-25mm deep repair boundaries, jackhammer removal exposing corroded reinforcement with 20mm clearance behind bars, wire brush cleaning removing rust and contaminants, Nitoprime Zincrich dual-coat application to cleaned steel, substrate saturation and Nitobond HAR bonding primer scrubbed application, and Renderoc HB40 Plus structural mortar built in successive 40mm layers matching existing profiles with formed repairs for depths exceeding 50mm. Concrete crack repairs wider than 0.3mm utilised wet grinding removing contaminants, 5mm depth grinding enhancing resin penetration, injection flange installation at 200-500mm spacing with 10mm diameter holes, Nitomortar AP sealing creating resin-tight barriers, and sequential Nitofill LV epoxy injection from lowest flange upward until complete saturation confirmed by adjacent flange discharge. CMP corrosion repair methodology included vegetation removal and 2-metre perimeter cleaning, dewatering and culvert cleaning unit deployment, full internal high-pressure cleaning and industrial vacuum drying, abrasive blasting from inlet to outlet exposing clean metal, and three-coat protective system with primer application within four hours preventing flash rusting followed by intermediate and topcoat applications. CMP widening replacement at Gregory-Oaky Creek inserted two 1300mm Roundel Brand pipes within collapsed 1800mm CMP, employing formwork support, breather hose air displacement during grout pumping, and progressive annular void filling with controlled pressure and hose withdrawal ensuring complete fill. Protective bollard installation at Marmor-Bajool positioned six 1.4m yellow steel posts with reflective tape protecting drainage infrastructure.
Deliverables
Sterling delivered comprehensive maintenance across 20+ sites including concrete spall repairs to reinforced concrete box culverts, pipe culverts, headwalls, and wingwalls using saw-cutting, structural mortar application, and profile matching techniques ensuring long-term durability. Crack injection repairs addressed defects ranging from 0.3mm to 6mm using epoxy resin systems preventing water ingress and structural degradation. Abrasive blasting and protective coating application treated multiple corrugated metal pipe culverts with full three-coat systems including zinc-rich primer, intermediate coat, and topcoat applied to manufacturer specifications. CMP liner installation at Gregory-Oaky Creek successfully rehabilitated collapsed 1800mm pipe through insertion of 1300mm liner with complete annular void grouting. Six yellow reflective bollards installed at Marmor-Bajool provide ongoing protection for critical drainage pit infrastructure. Site preparation works included vegetation removal, dewatering, debris removal to approved stockpile locations within 2km radius, and restoration of surrounding areas. All repairs utilised Fosroc product systems including Nitoprime Zincrich, Nitobond HAR, Renderoc HB40 Plus, Nitomortar AP, Nitofill LV, and Conbextra, with material certifications and application procedures compliant with manufacturer specifications and Aurizon standards.
Outcome
The project successfully renewed critical drainage infrastructure across Aurizon Queensland coal rail network enabling continued safe heavy haul operations through wet season periods. Comprehensive concrete repairs addressed exposed reinforcement and structural deterioration preventing progressive degradation and maintaining load-carrying capacity of culverts and bridge elements under heavy axle loads. Crack injection repairs eliminated water ingress pathways reducing freeze-thaw damage risk and reinforcement corrosion progression. Abrasive blasting and three-coat protective systems extended service life of corrugated metal pipe culverts in corrosive environments typical of Queensland coastal and inland locations. CMP liner insertion at Gregory-Oaky Creek provided cost-effective rehabilitation alternative to complete pipe replacement, maintaining hydraulic capacity while avoiding extensive track occupation and ballast disturbance. Protective bollards at Marmor-Bajool prevent vehicle damage to drainage infrastructure reducing emergency maintenance requirements. Sterling identified 38 additional severe defects during Site 7 inspections demonstrating proactive asset condition assessment capability, allowing Aurizon to address deterioration before critical failure. Practical completion by December 2025 ensured drainage infrastructure readiness before wet season operations, maintaining network reliability for Queensland coal export supply chain.
Explore More Projects
View our full portfolio of infrastructure projects across Australia
View All ProjectsReady to Start Your Project?
Let's discuss how we can help deliver your infrastructure needs
Contact Us