Interspan – Civil & Infrastructure Division

Interspan’s Civil & Infrastructure Division builds on over 20 years of expertise in post-tensioning, construction methodology and structural strengthening.

We deliver efficient, sustainable solutions for bridges, tanks, ports and energy infrastructure, helping clients reduce costs, save time, and lower carbon across vital projects.

Why Choose Interspan:

Australia’s infrastructure pipeline continues to grow, but it faces significant headwinds, including rising material costs, program pressures, and skills shortages.

Interspan helps clients overcome these issues by:

Smarter Use of Materials – Post-tensioning and strengthening solutions cut the amount of materials and reduce cost and embodied carbon.

Modular Thinking, Faster Delivery – Heavy handling and modular construction methods streamline builds, reducing program duration.

Innovation That Speeds Up Projects – Advanced methodology and skilled teams accelerate construction while maintaining quality.

Efficiency at Scale – 350+ designers and construction specialists driving productivity across civil projects.

Markets We Serve

Bridges: Solutions for new builds and maintenance, including post-tensioning, strengthening, and construction methodology.

Tanks: Crack-controlled, modular post-tensioned tanks designed for a long service life.

Ports & Warehouses: Cost-effective slab-on-grade systems engineered with geotechnical collaboration.

Water & Energy Infrastructure: Advanced solutions for dams, wind farms, and other critical assets.

Ground Engineering: Comprehensive foundation packages including anchors, soil nails, and grouting.

Services

EXISTING STRUCTURES

Interspan helps clients extend the life of their assets with advanced maintenance, repair and strengthening solutions. We’ve delivered hundreds of successful projects and are proud to be recognised as an industry leader in structural strengthening.

External post-tensioning is a proven active strengthening method for upgrading existing structures, including bridges, buildings and tanks. It involves installing prestressing cables or bars outside the structural section, guided by deviators along the most effective load path.

MORE

Replacing bearings and expansion joints is essential to restore performance and extend the service life of ageing bridges and civil structures. Upgrading these components restores the structure’s ability to accommodate movement, rotation, and stress, improving durability and long-term serviceability.

MORE

Jacking and structural monitoring are both critical parts of any safe load transfer process and require expert engineering guidance.

Interspan designs custom solutions for diverse projects that require precision loading/unloading and monitoring of structural elements.

MORE

Forensic services are often utilised to assess potential compliance issues between the approved structural documentation and
the built structure. We utilise both non-destructive and destructive testing methods to understand the composition of existing structures.

MORE

Over the last decade, Interspan has developed proven epoxy-based, retrofitted Tendon Truncation procedures that ensure post-tensioned tendon forces can be safely transferred into the remaining structure.

Our teams have decades of experience with post-tensioned structures, and we know how and where to use truncations as well as how to install them safely.

MORE

We have significant experience with structural grouting, and our pumps can mix and place proprietary grouts with or without cementitious or epoxy-based aggregate.

MORE

Corrosion is one of the most common and expensive durability issues stakeholders encounter in both building and civil structures.

MORE

We understand structures. We know why they crack and how to fix them. Our experienced teams design custom solutions to address any kind of crack that emerges. Typically, a crack is the symptom of a problem, not the cause.

MORE

We promote innovative, proven solutions utilising various CFRP-based strengthening techniques depending on the nature of strengthening required for your project. Our knowledge and experience in this area are second to none, and we’re extremely proud of the work our teams do every day.

MORE

We provide solutions for all types of concrete repair. Whether it is due to deterioration, carbonation, damage, or defective concrete, we put forward a remediation solution to ensure the section’s durability and strength are fully reinstated.

MORE

NEW STRUCTURES

The Interspan Group brings unique expertise in post-tensioning, construction methodology, and lifting operations that reduce CO₂ emissions, material usage, and construction program.

Innovative construction methodologies enable works to be completed outside the critical path in a safe and controlled environment. This approach reduces project costs and schedules, improves safety, and minimises disruption.

MORE

Interspan has extensive experience in the supply and installation of post-tensioning works in bridges, using state-of-the-art equipment to apply uniform stress to the separate strands of the tendon simultaneously.

MORE

Lifting and jacking operations are essential when prefabricated elements or existing structures need to be moved, raised, or installed with precision.

These techniques reduce reliance on heavy craneage, minimise risks, and enable construction in challenging environments or tight timeframes.

MORE

Stress bar post-tensioning systems provide a cost-effective solution for applying post-tensioning forces to short, straight tendons without requiring any profiles.

MORE

Through effective design, post-tensioned slabs enable material and embodied carbon reductions versus a conventionally reinforced slab, while maintaining the inherent benefits of concrete construction.

MORE

Sample Projects

Interspan_Port_botany

The Sydney AutoStrad Botany Rail Expansion (Project SABRE), co-funded by NSW Ports and Patrick Stevedores, was developed to double the port’s rail capacity.

The facility is designed to handle up to 500,000 TEUs (shipping containers) annually by rail. A post-tensioned (PT) slab was chosen for the main storage area to reduce construction costs, limit the number of joints, decrease maintenance needs, and extend the structure’s overall lifespan.

by NSW Ports and Patrick Stevedores, was developed to double the port’s rail capacity. The facility is designed to handle up to 500,000 TEUs (shipping containers) annually by rail. A post-tensioned (PT) slab was chosen for the main storage area to reduce construction costs, limit the number of joints, decrease maintenance needs, and extend the structure’s overall lifespan. by NSW Ports and Patrick Stevedores, was developed to double the port’s rail capacity. The facility is designed to handle up to 500,000 TEUs (shipping containers) annually by rail. A post-tensioned (PT) slab was chosen for the main storage area to reduce construction costs, limit the number of joints, decrease maintenance needs, and extend the structure’s overall lifespan.Interspan delivered the full scope of post-tensioning services, including supply, installation, stressing, and grouting. The company’s expertise in PT slabs, backed by CARES certification for quality assurance, was a key factor in De Martin and Gasparini’s decision to appoint Interspan for these works.

Interspan_infrastructure_division

The scope comprised the Warringah Road upgrade, a 1.3 km grade-separated underpass, and three associated underpass bridges.

Bridges were constructed in cast-in-situ (voided slab), post-tensioned concrete, enabling longer spans and adaptable geometry.

Interspan installed 21 tonnes of post-tensioning using 19-and 31-strand tendons.

The scope included threading, stressing and grout injection works, all carried out in full compliance with TfNSW B113 requirements.

interspan_greenland

The Greenland Centre Sydney is a landmark building retrofit that adds 45 levels to an existing structure.

Interspan has installed 1,200 metres of 75 mm diameter Post-tensioning Bars to connect the outrigger beam to the building core on Levels 26 to 28.

Our scope included supply, installation, stressing, and grouting, delivered to the highest quality standards and in line with project requirements.

Interspan_jane-street_bridge

Under the Jane Street and Mulgoa Road upgrade, a new rail bridge enabled the road to be widened from four to seven lanes.

Interspan was engaged to install 48 units of 75 mm diameter vertical stress bars to complete the final connection between the bridge and its foundations after installation.

Our experienced team carried out the stressing and grouting operations overnight during a road closure.

The Parramatta Aquatic Centre, completed in 2023 within Parramatta Park includes 33-metre span concrete beams that supports the roof above the main indoor pool, seamlessly integrated into the architectural design

A key structural highlight is the 33-metre span concrete beams that support the roof above the main indoor pool, seamlessly integrated into the architectural design.

Interspan delivered the full post-tensioning works for the beams, including design, supply, installation, stressing, and grouting works. The scope included 70 tonnes of post-tensioning with 12-strand tendons using 15.2 mm strands. A 300-tonne multi-strand jack was employed to stress all strands of each tendon simultaneously, ensuring homogeneous tension distribution across the structure

interspan_civil-and-infrastructure

6 & 8 Parramatta Square is one of Australia’s most iconic commercial developments. Rising 55 storeys and 243 metres.

The structure includes post-tensioned slabs and a complex outrigger truss system, requiring innovative solutions in prefabrication and load transfer during construction.

Interspan delivered 700 tonnes of post-tensioning across all 55 levels of slabs.

Vertical post-tensioning was implemented on the outrigger using 57 mm diameter PT bars, while horizontal 75 mm diameter bars were installed to connect the outrigger beams to the building core.

To streamline the program and enhance site efficiency, Interspan assisted the builder by prefabricating reinforcement cages with integrated PT bars off-site, supplying them ready for direct installation.

In addition, Interspan supplied and installed 16 flat jacks of 1000mm diameter to transfer the loads from the upper levels into the outrigger beams upon

completion of construction. This provided a controlled load path fully consistent with the structural design requirements.

Interspan Heavy Lifting

Completed in 1895, Tharwa Bridge is the ACT’s oldest bridge and the oldest surviving Allan truss bridge in Australia.

Extensive strengthening was undertaken, including the replacement of original truss members. During installation of the new trusses, the deck was secured by a temporary underslung steel beam assembly installed beneath the four truss spans, each over 27 metres in length.

Interspan proposed and executed a bespoke heavy-lifting methodology to install and dismantle the temporary underslung steel beam.

The strand-lifting solution delivered a cost-effective and rapid implementation while safeguarding the bridge’s heritage value.

AEROTROPOLIS_STATION

Aerotropolis Station forms part of the new Sydney Metro line, linking Western Sydney Airport to St Marys.

The station box structure has been built using precast beams, which are interconnected with stressed bars to ensure the elements act as a single structure.

Interspan successfully stressed 180 high-capacity 36mm post-tensioning bars, ensuring structural performance and reliability.

Nation Infrastructure Manager_Pierre-Yves Souesme

Global Reach

With offices in Australia and a global presence, Interspan has the reach and expertise to support projects worldwide.

Ready to discuss your next project?

Contact Pierre-Yves Souesme, National Infrastructure Manager, to review scope and feasibility.

Email Pierre-Yves

Loading Viewer...