Andy Powell, the Environment Agency’s innovation manager, says it is crucial to lead in low-carbon infrastructure.
The Environment Agency is a champion of the environment, and we encourage others to take action in climate adaptation and resilience. He says that as infrastructure owners, we must also lead by example.
Our goal is to reach net zero by 2030. This is a reduction of carbon emissions of 45% from the baseline that we established, with the rest offset. We are currently conducting research on how the offset will look, but we will be focusing on planting on our sites rather than paying an outside organisation to do it.
The Environment Agency had produced 273,000 tonnes of carbon annually when it established the strategy. 148,000t was accounted for by construction activities.
Net zero commitment
The Environment Agency’s ability to meet its 2030 net zero goal was likely to be affected by the way it tackled the carbon associated with flood defenses construction. The Environment Agency has established a number of working group to highlight the importance of leading by example.
The Environment Agency pledged to use low-carbon concrete in flood defenses. This was a direct result from work done jointly by Jacobs and the agency.
The concrete focus was on one of many task and finish groups. These groups, in addition the concrete study, also focused on site set-up and equipment; asset repair, modern methods of construction, alternative low carbon solutions, and steel piling. Each partner involved with the Environment Agency. Jacobs was not the only partner in these groups. Volker Stevin and Kier were also involved.
Powell explains that the categories were derived from previous work that identified them in our carbon footprint as hot spots.
215tCO in savings on low carbon concrete2e on the Hythe Ridges sea defences project, Kent
Powell says that having outside contractors and design partners was crucial to the work’s success. It ensured that the decisions were based upon industry best practice.
He says that we were trying to find the best practices and innovation in our own activities and those of other infrastructure clients.
It was our goal to bring everything together and find a way to make business as usual using our engineering standards. The goal is to make low-carbon business as usual.
In May 2020, the task and finish groups were formed. After the results were compiled, the focus moved to 11 pilot programs across the country to put the ideas into practice.
Our main point is to use the lowest carbon concrete in order to meet the performance requirements.
Some pilots remain at work, but Powell mentions the Hythe Ranges maritime defenses in Kent, where 215tCO are being deployed.2Low carbon concrete saved e. The scheme also saved 1,445tCO through other initiatives.2e and produced financial savings of 2.5M. The total carbon cost for the 25M scheme was 9,576tCO2e.
Powell explains that the concrete and reinforcement finish and task groups looked at concrete standards and carbon reduction opportunities for concrete components.
This information was used to suggest an approach that could work within the Environment Agency. The next phase was to put that into practice by changing our standards and creating guidance that would be useful for project teams. The report includes a technical summary and a flowchart to guide teams through the thinking process required to adopt low-carbon concrete solutions. It helps them decide if they are following the correct approach for a particular scheme and encourages them to consider low-carbon solutions early in a project.
Cement replacements
The site is now focusing on cement replacements using secondary cementitious material such as granular ground blast slag or pulsed fuel ash. These materials are being used to replace approximately 80%. Portland cement can be supplied with the normal Portland cement content as long as it meets existing standards.
Powell admits that it is not novel. It is something we can do easily now, and we are focusing efforts on the more innovative products like Cem-Free concrete and Earth Friendly concrete in the right applications to further reduce our dependence on traditional cement.
The new approach is based on risk. The technical report recommends that you stay within the concrete standards for safety-critical applications like flood walls, and use low-carbon solutions in low-risk, nonstructural applications.
Powell says that the main point is to use low-carbon concrete to meet performance requirements. Jacobs and the Environment Agency won the trophy in the Environment and Sustainability Initiative category of the 2021 British Construction Industry Awards (BCIA).
Centre stage
Powell says that although the BCIA win placed work front and center, knowledge sharing was a key component of all task and finish groups.
He explains that we drew upon the best practices of other infrastructure clients through the project partners, and they returned the knowledge we gathered to their other clients as well.
The knowledge gained from the work will soon become more widely shared and in a more formal way. Powell’s work with Jacobs was a key part of the development of the ICEs Low Carbon Concrete Routemap. It is due for publication shortly.
This document is the result of the Low Carbon Concrete Group’s (LCCG) work. It was created by the Green Construction Board, which serves as the Sustainability Workstream of the Construction Leadership Council.
Powell states that the interim work we have done so-far with the Environment Agency is temporary because the only real solution is changing the standards.
Powell says that the LCCG’s work is helping to change standards in the construction industry to make it easier for low-carbon concrete to be specified and used.
Concrete is a versatile and important material. I believe we will continue to use it in the future. However, its use must be optimized, says Powell.
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