Infrastructure Needs To Square The Circle – We Must Embrace The Excitement And Challenge Of Delivering More Sustainable infrastructure

In this guest blog, Mark Coates, Vice President of Infrastructure Policy Advancement at Bentley Systems, argues that we must not only accept our transition to a circular economy, but also fully embrace it.

Last year, I joined over 100 peers including those at the National Infrastructure Commission, World Economic Forum, and World Green Building Council and pledged to make a positive difference in accelerating our transition to a circular economy in the built environment. This year’s Earth Day focused on reducing the use of plastics, including a 60% reduction in plastic production by 2040.

However, given the industry that I work in and the pledge that I made, it’s more important to look at the larger and more holistic challenge of material use. I’d also like to champion international best practices, as well as highlight the business cases and business opportunities, that will arise as part of the transition to a circular economy.

In writing this piece, I’m reminded of the work of William Bridges, the United States’ preeminent authority on change and transition, whose work showed how all healthy transitions consist of an ending, a neutral empty period, and a new beginning.

The end of the current ways of doing things, and the transition to net zero and a more circular economy, is being greeted by fear, denial, sadness, and anger by some. However, as with all changes, we must accept that change is coming and embrace it to make the most of it.

The transition to a circular economy will create new opportunities to do things more efficiently and more sustainably. Importantly, from a commercial aspect, this transition will provide new opportunities for businesses to create value.

In a world where resources are finite, successful businesses of the future won’t be the ones who are the best at extracting and using resources. The most successful businesses will be the best at reusing resources.

The Impact of Construction and Infrastructure

Those of us working in the construction and infrastructure sectors probably have more skin in the game when it comes to resource reuse than most other most other sectors, as construction and infrastructure currently consume more resources than most other sectors.

Analysis by the Global Infrastructure Hub found infrastructure consumes around 60% of the world’s materials, while it contributes around 10% of global greenhouse gas (GHG) emissions through construction and 43% during operations.

In 2021, the European Commission published a “what’s in it for me” report for construction companies, contractors, asset managers, facilities managers, and occupiers, highlighting that, across the full lifecycle of buildings, the sector is responsible for half of extracted materials, half of total energy consumption, a third of water consumption, and a third of waste generation. The infrastructure sector is also a major consumer of chemicals, electronic equipment, and related services.

In the U.K., a 2022 briefing paper for the Construction Products Association showed that construction and maintenance of roads, railways, homes, offices, and the wider built environment uses the greatest volume of materials, as well as delivers the largest waste flows by tonnage. It’s important to note that, in England and Wales, more than 90% of this waste is recovered mainly for use as aggregate. However, five million tons of construction and demolition waste still finds its way to landfills.

These trends concern me on a personal and professional level. The legacy of what we leave for future generations was part of my motivation in signing the pledge to accelerate our transition to a circular economy.

Going Dutch

Having examined some solutions created during our transition to a circular economy, I’d like to celebrate some recent successes delivered by fellow Europeans in the Netherlands.

Circular Infrastructure: the road towards a sustainable future is a paper written in collaboration between Rijkswaterstaat, Holland Circular Hotspot, The Transition Team Circular Construction Economy, Rebel Group, and The Netherlands Organisation for Applied Scientific Research.

The paper highlights that more than 20 million tons of materials are used every year in Holland to expand and improve roads, canals, and underground infrastructure, and the consumption of resources, energy, and water in the infrastructure sector is in line with European Union averages.

In the Netherlands, many infrastructure installations, such as viaducts, do not reach their estimated lifespan and are demolished much earlier for functional reasons. Construction of Holland’s first circular viaduct began when Esther van Eijk, a project leader at van Hattum en Blankevoort (vHeB), challenged her team to see if it would be possible to construct a circular viaduct. The aim of the pilot project was to develop a bridge that was as close as possible to 100% reusable in a new location – significantly extending lifespan, reducing material usage and waste, and supporting sustainability.

In 2018, a small group of collaborators from vHeB, Rijkswaterstaat, VolkerWessels, and Consolis Spanbeton explored what a circular viaduct might look like. They created a 20-meter-long bridge consisting of 40 precast reinforced concrete elements assembled into five girders to form a 7.4-meter-wide deck, which was built in the Dutch city of Kampen, about 80 kilometers northeast of Amsterdam. Each girder is created by eight elements, which are connected using prestressing cables and have specially designed shear keys at the joints.

On December 4th, 2018, the main contractor was the first to successfully cross the viaduct in his car, followed by a large convoy of road vehicles as the circular viaduct was officially opened by the Minister for the Environment, Stientje van Veldhoven, in 2019. After being in service for ten months, it was rebuilt for public use at a new location in the Dutch city of Almere.

Estimates suggest the viaduct’s circular bridge elements have a lifespan of around 200 years – much longer than a traditional bridge, as they can be dismantled and reused when they are no longer required in the original location. The only material that could not be reused is the grout between the precast elements – less than 0.5% of the total. Grout was chosen over epoxy because it enabled the elements to be separated after use.

Jan Willem Spruit, technical manager at Rijkswaterstaat, said that adapting the existing design to create a wider or longer structure is quite straightforward: designers can add additional beams to make the bridge wider or additional units to make the beams longer. But the maximum span length with this design is around 25 meters. However, if intermediate supports can be accommodated, a series of spans, each up to 25 meters long, could be used to create a longer bridge.

The Netherlands has demonstrated further expertise with circular bridges in recent years. In 2022, the world’s first ‘smart circular bridge’ was built in Almere.

The Eindhoven University of Technology led a project to build a bridge partly made from flax, a plant also known as linseed, to demonstrate the material’s potential to replace steel in construction. The bridge was built from flax fibres combined with bioresin and polyurethane foam blocks, creating a light and stable composite material that can be used instead of aluminium or steel.

It is the first of three bridges for pedestrians and cyclists that will be built as part of the Smart Circular Bridge project, with the next two destined for Ulm, Germany, and Bergen Op Zoom, the Netherlands.

Making the Transition

In reflecting on our transition to a more circular economy, I’m reminded of a quote from William Bridges: “Change comes more from managing the journey than from announcing the destination.”

How successful we will be with moving to a more circular economy depends on how well we manage the transition and how we communicate to people during the transition.

However, I’d like to remind any skeptics about what lies ahead of us on this journey. As Bridges said, “It is when we are in transition that we are most completely alive.”

It is important for us all to remember and embrace this excitement as our businesses, our society, our culture, and our behaviour change as we all transition to become more sustainable.

Godspeed and best wishes to you all wherever you may be in this transition.