Detailed analysis of the barriers and opportunities to reuse steel in bridge design has been laid out in a “groundbreaking” new report.

Expedition Engineering has published Steel Reuse in Bridges, which examines the reuse of structural steel in bridge design and construction. Led by Expedition Engineering project director Clotilde Robin and principal researcher Hazel Needham, it provides insights into overcoming barriers to implementing circular economy principles in infrastructure projects.

It also outlines the steel and steel reuse lifecycle to demonstrate how steel can be reclaimed from existing infrastructure assets and the demolition market.

Steel Reuse in Bridges - steel lifecycle diagram

Sustainability

With the construction sector under increasing pressure to decarbonise, the report, which was supported by funding from the Institution of Civil Engineers (ICE), highlights how steel reuse offers a viable, cost-effective, and sustainable alternative to traditional recycling methods.

Despite advancements in recycled or “green steel”, the report emphasises that reducing demand through reuse remains a crucial sustainability strategy.

“Simply recycling steel is no longer enough - proactive efforts to reuse existing materials with minimal post-processing will be essential in addressing the climate crisis,” the report says.

NCE has previously reported that steel reuse offers up to 97% embodied carbon savings compared to using new steel and is 10 times less carbon intensive than recycling, according to not-for-profit organisation the Alliance for Sustainable Building Products (ASBP).

Figures from the UK Green Building Council (UKGBC) confirm 99% of all UK structural steel sections are currently recovered, with 86% sent for recycling – typically electric arc furnace (EAF) recycling – and 13% for reuse.

Pathways to reuse

Expedition’s report identifies three key pathways for implementation:

Steel Reuse in Bridges - pathways to reuse

While regulatory constraints, procurement challenges and risk management concerns have historically limited steel reuse adoption, the research is designed to address these issues, providing guidance on material qualification, certification and design life considerations for repurposed steel in bridges.

Key priorities to ensure greater uptake of reused steel in project include “rigorous material testing to confirm the geometry, condition, and structural integrity of reused steel”, the study states.

Fatigue life

“A crucial factor in bridge applications is assessing fatigue life to determine long-term viability,” according to the report. “Certification and compliance processes are expected to evolve, shifting toward a testing-based approach rather than reliance on CE or UK marking for individual components.”

Previous and future fatigue life is another consideration.

“Fatigue can significantly impact the design life of a structure,” the report says. “Current guidance is restrictive about reused steel from and for bridges subject to fatigue. However, with the right level of assessment, inspection and engineering judgement, some reuse is possible.”

The report includes several case studies demonstrating that footbridges emerge as a viable typology for reclaimed steel, due to their lower fatigue sensitivity and the relative ease of implementation, as demonstrated by the Lucie Bréard footbridge in Paris.

Case study: Lucie Bréard footbridge - Paris

The Paris 2024 Olympic games focused on improving accessibility for all, necessitating the construction of a new footbridge - the Lucie Bréard footbridge - over the Canal Saint-Denis to replace a moveable bridge, whose rotating mechanism was prone to failure.

Lucy Bréard Bridge, Paris - a case study by Schlaich Bergermann and Explorations Architecture - copyright Michel Denance

The design team proposed reuse of the main span of the road bridge as the new pedestrian and cycle footbridge.

The alignment would be altered and the level raised by 5.5m above water to allow for commercial navigation.

The reused span is a 52m-long and 13m-wide orthotropic steel box girder.

A visual inspection and non-destructive tests confirmed that the structure was in good condition and due to the limited in-use service life of only 20 years, the bridge was not near the end of its fatigue life.

Parts of the foundations were also reused. New parts included the ramps and stairs, as well as the replacement of the deck edges that were corroded and not adequate to support the new balustrade. Other areas with signs of corrosion were repaired.

A barge, jack-up system and self-propelled modular transporters (SPMTs) were used to install the 280t bridge in two days.

The availability of the as-built drawings and justifications, the client’s support and ownership, and the tight programme contributed to the success of the project.

The project client was Plaine Commune; the designers and structural engineer was Schlaich Bergermann Partner; the architect was Explorations Architecture; the steel contractor was Eiffage Métal, and the civils and general contractor was Razel-Bec.

Conclusions

Despite the barriers to uptake, Steel Reuse in Bridges indicates that the supply chain for reusable steel is expanding, with fabricators and stockholders such as Cleveland Steel & Tubes playing an increasing role.

“The most successful reuse cases occur when clients own both the donor and recipient assets, streamlining logistical and commercial considerations,” said Expedition.

The study points out: “While reused steel is generally more cost-effective than new steel, additional costs may arise from testing, reconditioning, and logistics - particularly when relocating entire bridge spans.”

And it also emphasises the need for a resource-led, iterative approach to design and construction, requiring greater collaboration between designers, engineers, and contractors.

The full report, Steel Reuse in Bridges, can be found here.

NCE has reported separately that ASBP research indicates a critical gap lies in the underutilised role of demolition contractors.

Demolition specialists could be better incentivised to recover steel from buildings, according to ASBP. Meanwhile, pioneering projects and the work of organisations like The Engineers Reuse Collective (tERC) are working towards accelerating reuse in the built environment.

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