8 mins
Recycling bridges: How contractors are maximising material recovery
With aging infrastructure driving an increase in bridge demolitions, contractors are focusing on advanced recycling strategies and innovative technologies to maximise material recovery. This article delves into the methods, challenges, and opportunities shaping the industry.
The Carola Bridge, which was erected in 1971 and spanned the river Elbe in Dresden, Germany, partially collapsed at 3:08 am on September 11, 2024, sending a 100-metrelong section that held the city’s tramway tracks plunging into the river below. Fortunately, no one was harmed. Specialist contractor Centro Environmental Technology and Logistics was deployed to the site, alongside emergency services and a regiment of troops from Germany’s Saxony State Command of the Bundeswehr. Emergency demolition works to remove the collapsed Carola Bridge were completed in just 47 hours
CREDIT: CITY OF DRESDEN
The Gerald Desmond Bridge in California, US.
CREDIT: KIEWIT INFRASTRUCTURE WEST
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he global problem of aging infrastructure has positioned demolition contractors at the forefront of reshaping skylines and modernising essential assets. But as bridges, highways, and industrial facilities reach the end of their service lives, the industry faces critical questions. How can contractors maximise recycling efficiency while managing project profitability? And what role do legal frameworks and fluctuating material markets play in shaping the success of demolition projects? This article explores these issues, offering insights tailored to contractors navigating this complex landscape.
MAXIMISING MATERIAL RECOVERY: BEYOND STANDARD PRACTICES
While many contractors are proficient in recycling reinforced concrete and steel, the demands of modern projects require a more strategic approach. Aging structures often include composites or contaminated materials, such as lead-coated steel or chloride-infused concrete. Addressing these challenges increasingly involves technologies like robotic sorting systems and AI-enhanced identification tools. These advancements are not only boosting efficiency but are also helping contractors meet evolving environmental regulations. Urban demolitions, meanwhile, often lack the space required for extensive onsite recycling setups. Modular equipment, such as portable crushers and sorters, is proving invaluable in these constrained environments. By allowing for realtime material processing, this approach minimises disruptions to the surrounding area and reduces transport costs and timelines. Collaborating with material scientists or third-party recyclers further unlocks innovative reuse opportunities, such as transforming post-tensioned concrete into marine-grade aggregate or repurposing structural steel for modular construction.
RECYCLING CONTRACTS AND PROFIT SHARING
In many projects, demolition contractors and clients establish separate contracts to manage material recovery, often sharing revenues from the sale of recyclables. To ensure these agreements are advantageous, contracts must clearly define ownership of materials and establish profit-sharing ratios to prevent disputes and maintain project momentum. Addressing fluctuating material prices through escalation clauses helps safeguard profitability, particularly for high-demand resources like steel and aggregate. Involving legal and financial advisors in the structuring of these contracts ensures they align with both client interests and operational realities.
Gerald Desmond Bridge demolition
The Gerald Desmond Bridge demolition in Long Beach, California, managed by Kiewit Infrastructure West, serves as a model for innovative and sustainable demolition practices. This US$28 million project involved dismantling the 1.5-kilometer bridge in stages, including the removal of a 410-foot suspended span weighing seven million pounds. By lowering the span intact onto a barge during a 48-hour channel closure, the team minimised disruptions to port operations while maintaining high safety standards.
Recycling was a cornerstone of the project’s success. Kiewit recycled 15,169 tonnes of steel, crushed 68,000 tonnes of concrete for use in future port projects, and repurposed 22,063 tonnes of soil on-site or at designated facilities. Remarkably, the project achieved a 100% recycling rate, ensuring that no materials were sent to landfill.
Collaboration among multiple stakeholders, including port authorities, shipping companies, and oil facility operators, was essential. Weekly meetings and real-time communication helped align schedules and address challenges, such as working over active railroads and near oil wells. The project team’s coordination reduced impacts on neighbouring operations and achieved completion four months ahead of schedule, saving the client over $3 million.
This project highlights the importance of strategic planning, stakeholder collaboration, and innovative engineering in achieving efficient material recovery and operational success.
FINANCIAL AND LEGAL CONSIDERATIONS
The legal and financial dimensions of demolition projects are becoming increasingly complex. Handling hazardous materials, for example, often requires specialized insurance coverage. Documenting safety measures not only secures adequate coverage but also mitigates risks associated with hazardous material exposure.
The challenge of attracting bidders
The Washington Bridge project in Rhode Island highlights the challenges in meeting the rising demand for bridge demolition and replacement. In 2024, the Rhode Island Department of Transportation (RIDOT) received no bids for an $80 million demolition and rebuild project, forcing the suspension of plans. Similarly, a $779 million bridge replacement project in the state attracted only one bid, submitted by a joint venture between Skanska USA and Manafort Brothers.
This scarcity of bids reflects a broader issue: a limited pool of contractors with the financial and operational capacity to undertake large-scale infrastructure projects. Contractors cite rising costs, logistical challenges, and the sheer volume of available projects as key barriers to participation. Additionally, complex regulatory frameworks and risk-heavy contracts discourage potential bidders.
This scenario also underscores the opportunities for demolition contractors to expand their presence in the infrastructure renewal market.
By addressing logistical hurdles, adopting innovative methods, and advocating for streamlined bidding processes, contractors can position themselves to take advantage of the increasing demand for large-scale bridge demolitions and replacements.
Addressing this issue requires industry-wide efforts to expand the contractor pool, streamline procurement processes, and incentivize participation.
Without these measures, the growing backlog of infrastructure renewal projects will remain a significant obstacle to meeting national and global demands.
Compliance costs are another pressing concern, with tightening regulations requiring contractors to adopt robust tracking systems to ensure waste management standards are met. These systems also serve as a safeguard against penalties and bolster a contractor’s reputation for environmental responsibility. Contractual mechanisms for dispute resolution, addressing conflicts over material value or unexpected site conditions, further enhance project resilience.
Viaduct du Charmaix demolition
The Viaduct du Charmaix demolition in Fourneaux, Savoie, France, highlighted the transformative role of digital technology in overcoming logistical and environmental challenges. Situated on a steep mountain slope and adjacent to protected natural areas, the project required precise planning and execution.
Demolition contractor Despe employed advanced laser scanning and Building Information Modelling (BIM) to create detailed 3D structural simulations. These digital tools provided insights into the viaduct’s stability and facilitated the planning of dismantling sequences, including crane movements and material handling. The margin of error for crane operations was reduced to within five centimetres, even in the challenging mountain terrain.
Key structural elements were cut using diamond wire techniques and carefully removed with high-capacity cranes, including the Liebherr 11350. The precision offered by digital modelling enabled Despe to coordinate synchronised crane lifts at difficult angles, preventing structural instability during dismantling.
Additionally, BIM simulations allowed for the strategic reuse of 7,500 cubic metres of concrete onsite, which was repurposed for access track construction and crane platforms. This integration of technology significantly minimised transport demands and environmental impact, particularly in a protected natural area.
Despite severe weather conditions and the absence of utilities onsite, the project remained on schedule. The precise execution and innovative use of digital tools enhanced safety and operational efficiency, setting new benchmarks for the demolition of complex infrastructure in constrained environments.
CREDIT: DESPE
Jet Demolition recently demolished the Rockdale Road Bridge in KwaZulu-Natal, South Africa, as part of an ongoing upgrade to the N3 highway and EB Cloete Interchange. The operation took place overnight during a full motorway closure from 18:00 on a Saturday to 05:00 the following Monday. The removal of the bridge marked a significant milestone in the wider N3 project, which is due to be completed in July 2025.
CREDIT: JET DEMOLITION
THE ROLE OF TECHNOLOGY IN COMPETITIVE ADVANTAGE
Emerging technologies are becoming essential tools in modern demolition practices. Digital twins and predictive modelling, for instance, enable contractors to simulate workflows, anticipate challenges, and refine material recovery strategies before projects even begin. IoT-enabled systems provide real-time data on recycling progress, material yields, and compliance metrics, ensuring streamlined operations and enhanced transparency with stakeholders.
THE PATH FORWARD
The demolition industry is at a crossroads. Aging infrastructure is driving unprecedented demand, but success will depend on how contractors adapt to recycling challenges, legal complexities, and technological advancements.
By embracing innovative practices and forming strategic partnerships, contractors can lead the way in sustainable demolition while maintaining strong financial performance.
As infrastructure renewal accelerates worldwide, the role of demolition and recycling companies has never been more critical.
By addressing material recovery, refining contractual frameworks, and embracing cutting-edge technology, the industry can not only meet today’s challenges but also set new standards for efficiency and environmental stewardship.
Estimating bridge replacements over the next five years
Across the globe, aging infrastructure continues to place increasing strain on bridge networks. In Europe, several countries face significant challenges. Germany, for instance, reports that approximately 5,000 autobahn bridges are in dire need of renovation or reconstruction, while up to 20% of the 38,300 bridges on federal roads require refurbishing.
The UK, meanwhile, is grappling with a backlog of infrastructure projects; recent data from local councils and National Highways indicates that dozens of key road and footbridges require immediate replacement, including high-profile structures like Hammersmith Bridge in London. Italy also faces mounting concerns about aging bridges, particularly following the Genoa Morandi Bridge collapse, although precise data remains elusive.
In North America, the American Road and Transportation Builders Association (ARTBA) estimates that over 76,000 bridges in the United States alone are in need of replacement. In Canada, many bridges constructed during the mid-20th century are reaching the end of their lifespan, though comprehensive figures are not readily available. In Asia, India’s vast infrastructure includes many older bridges requiring upgrades, particularly in rural and flood-prone regions, while Japan’s post-war bridges, now over 50 years old, are also increasingly targeted for replacement. Meanwhile, in South America, countries like Brazil and Argentina struggle with limited funding for infrastructure maintenance, leaving critical repairs and replacements deferred.
In Africa, South Africa’s Welisizwe Rural Bridges Programme aims to address bridge damage caused by severe weather, particularly in rural areas. The programme highlights a broader regional trend where resource constraints hinder timely replacements. In Oceania, Australia is investing in renewing rural and urban infrastructure, but comprehensive data on bridge replacements remains sparse. Globally, while countries are at varying stages of identif ying and addressing aging infrastructure, the combined estimates suggest that hundreds of thousands of bridges will require replacement in the next five years to ensure safety and connectivity.