The road and infrastructure construction industry faces steep challenges as it squares up to the issue of carbon reduction. In materials, in the construction process itself and in infrastructure maintenance and repair, the UK’s roads and bridges contribute significantly to carbon emissions. Harnessing a collective will to decarbonise, however, is a significant commitment.

At a roundtable hosted by CIHT, in association with Atkins, professionals from materials and construction companies, consultancies, national agencies and local authorities discussed innovations around carbon reduction, the role of industry measures, as well as progress on PAS 2080.

Sue Percy, CIHT’s CEO, set the scene for the discussion, reiterating CIHT’s commitment to decarbonisation and how imperative it is to find solutions to these challenges. Responding to a changing world is part of CIHT’s Strategy 2022+, and developing, delivering and maintaining sustainable solutions for highways, transport infrastructure and services is how the industry can achieve that vision.

Lila Tachtsi, National Highways’ asset management director, said the organisation is committed to the environment and to carbon reduction and sees net zero as an essential pillar of its sustainability work.
It has published a progress report on its Net Zero plan with the aim of being ambitious and clear about the actions needed. This goal, she emphasised, is not just a challenge for the company, but a global one which the sector needs to cooperate on. Quick wins such as the move from hot to warm mix asphalt are welcome, but the next steps will require a coordinated effort and focused ideas.

New Materials

From a construction materials perspective, the most carbon-intensive offenders are widely recognised and understood. Darren Checksfield of Aggregate Industries said 70% of Aggregate Industries’ materials emissions come from cement manufacturing. Reducing those by finding alternative methods or materials is therefore a critical focus. Other factors include steel and the amount of diesel employed in construction.

Alternative materials – such as ground granulated blast-furnace slag (GGBS), a by-product of iron and steel production – could replace between 30% and 80% of the cement in concrete. Aggregate Industries showcased its use with a statue made of GGBS and recycled glass, displayed at COP26. However, recycled materials come with unique challenges, since large infrastructure projects require materials with proven performance data and, in some instances, demonstrable early-life strength.

That said, innovation is very much a focus for the industry. For example, GGBS was specified as a high-volume cement replacement to produce structural grade concrete for use in High Speed 2 which has been successful, but key to future application will be ensuring that a credible source for supply of GGBS exists and this will be a challenge, Paula Gough, key account director for National Highways at Costain, pointed out.

The safety factor is central to this part of the carbon reduction debate. National Highways standards for highway construction – used around the world – exist to ensure safety. The company is looking at how it can make the standards process quicker and more agile, said Tachsti, but it must ratify only those materials that will stand the test of time. Ultimately, net zero is best achieved, she went on, through methods and materials which minimise maintenance over the life of the asset. 

Turning to large-scale projects, John Dixon, vice president at Jacobs, saw an opportunity to put substantial collective investment into a single programme which could boost confidence in low-carbon materials, leading in turn to wider take-up. Two major UK projects are targeting around 30% reductions in carbon emissions, he said, and are widely seen as pushing the boundaries of what is achievable.

To do so also involves incentivising the supply chain to participate in carbon-reduction efforts, the panel agreed. To cut CO₂ emissions overall, cement, concrete and fuel supply will need to be targeted. A supply chain that is motivated to maintain focus on specific targets – right through to smaller companies where legacy issues abound – is an essential part of the picture.

Design and planning

Tony Meehan, a director leading the UK transportation consultancy at Atkins, argued that we need to look even further back in the process to the concept, design and planning stages. Huge emissions savings are to be made if the initial design stages are focused on cutting emissions, he said. Chris Kennedy, senior engineering manager at Balfour Beatty, added that low-carbon designs coupled with a procurement and bid process which embeds responsible suppliers at the earliest stages would radically alter the landscape. 

It was an idea which gained traction in the group discussion. Philippa Horton, business manager for the Use Less Group in the Department of Engineering at the University of Cambridge, spoke about her department’s work on building design software which takes a macro approach, effectively putting thousands of designs on the table and bringing into the early stages of design and planning the whole ecosystem of stakeholders, from architects, infrastructure engineers and clients through to the entire supply chain.

Even with such tools, she advocated taking a step further back and discussing transportation needs at a policy level: “Rather than just looking at an individual piece of road and asking ‘How can we make that road more efficient?’, we should say ‘What should the service be to help these people move from A to B? Should it be a road network or a train, for instance?’”

Costain’s Paula Gough agreed. The procurement and planning stages are absolutely key, she said. If handled correctly, an early engagement procurement model could be “the gift that keeps on giving”.

This outcomes-led approach might result in specified carbon budgets being set across a region, suggested Andrew Crudgington, researcher and technical writer at CIHT.

However, cross-discipline involvement is key, said Jonathan Holyoak. “Private sector companies – like Atkins – have a key role to play in leveraging cross-sector expertise and innovation; for example, across buildings, energy and water, as well as transportation,” he noted.

PAS 2080

So, what are organisations doing differently now on carbon reduction compared with previous decades? Balfour Beatty is seeing more of this outcomes-focused approach to contracts, Kennedy argued, embedding the principles of PAS 2080 into the decision-making process and thinking about carbon reduction across the full matrix of costs, logistics, customer needs and impact.

At Jacobs, meanwhile, training has been provided to help improve carbon literacy in all staff across all lines of business.

Checksfield said at Aggregate Industries, research and development is heavily focused on carbon reduction and use of recycled materials.

However, Meehan argued that, taken in its entirety, the infrastructure sector is moving slowly. Training, tools and processes aligned with PAS 2080 are in place, but the standard may act as a brake in some circumstances. “It is absolutely right that PAS 2080 continues as a thread throughout what organisations are doing. But does it go far enough? The way [projects] are procured [today] is that you’re incentivised to get to a particular point, but not perhaps incentivised to go further.”

Another difficulty comes to light when you consider build programmes conceived prior to PAS 2080 and the current focus on net zero. As Jacobs’ Dixon said: “I see a lot of change from the materials side, but how we deal with projects conceived before PAS 2080 is a question mark, because [those projects] won’t be delivering on zero carbon. Ultimately, we also have to ask ourselves: have we got the right project here? Are we looking at our infrastructure projects in the right way? Should the projects themselves be recycled?”

Looking at these legacy issues brought the group to the topic of maintaining existing infrastructure. Local authorities in particular face a huge issue when it comes to replacing or maintaining assets in the face of long-term underfunding. As Clive Lambourne, team leader at Kent County Council and an Association of Directors of Environment, Economy, Planning & Transport (ADEPT) representative, put it: “You look at our networks across the country, and they are generally only just holding steady or declining. If we suddenly find maintenance is going to cost more, how are we going to fund that?”

The National Highways perspective on PAS 2080 is that it could be achieved ahead of time. Tachsti called for cross-sector investment and collaboration and pointed out that carbon emissions are just one aspect of sustainability. Biodiversity, clean air and water are also very high on the agenda.

Assessing progress

When it came to international comparisons and lessons, Gough held up Europe for its progress towards digital roads and big battery technology. Dixon said that while the US could be considered behind in terms of the lack of impact assessments implicit in Joe Biden’s infrastructure bill, great strides have been made around road transport technologies such as embodied carbon and induction charging trials.

All in all, collaboration and a willingness to go further was very much in evidence in the discussions. But the challenges, as Meehan pointed out, are immense, and the sector cannot afford to defer any area of its carbon reduction and sustainability efforts.

With thanks to Atkins for its support. Atkins is a leading design, engineering and project management consultancy. Learn more about its infrastructure work at www.atkinsglobal.com, or email tony.meehan@atkinsglobal.com

Meet the panel 

John Dixon- Jacobs

Paula Gough – Costain

Chris Kennedy- Balfour Beatty

Darren Checksfield- Aggregate Industries

Philippa Horton- University of Cambridge

Clive Lambourne- Kent CC & ADEPT

Tony Meehan- Atkins

Lila Tachsti- National Highways

Jonathan Holyoak- Atkins

Sue Percy- CIHT

Andrew Crudgington- CIHT