Learnings

Outcomes

A comprehensive set of lessons learned has been developed and shared with the business which will help inform colleagues and the energy market on the progress with different concrete types available. Polymer concrete are expensive and there are better materials available for use as compared to polymer.

The use of novel, low carbon concrete materials will form only a small part of the solution to reducing carbon emissions. As discussed, wider industry is primarily investigating other means of decarbonising concrete, including through more effective design, carbon capture, and decarbonisation of the traditional OPC processes. Based on their responsibility within the supply chain, NGET will struggle to directly influence and impact these solutions. Hence, novel material use is one of the key decarbonisation strategies NGET can directly influence.

Within low carbon, novel materials, SCMs are primarily being investigated as opposed to polymer concretes. Industry is primarily investigating the use of SCMs as a replacement to OPC, due to the similar material properties to CEM mixes, and potential abundance of alternative materials to support growing demand. Although polymer concretes do have a relatively lower carbon content than CEM I OPC mixes, the carbon emissions within CEM III and other lower carbon mixes are comparable to PMCs (which are a relatively better solution for NGET compared to PRCs). As wider industry is primarily investigating the use of SCMs as a solution, these will likely drive economies of scale, reducing the cost of these materials further. Finally, using government HMT Green Book guidance, results from the CBA have indicated that polymer concretes do not currently form an effective means decarbonising.

Polymer concretes do have advantageous properties which may benefit NGET; however, the price premium is considerable. These properties include higher durability, mechanical strengths and faster curing times. In particular, the speed of curing may provide large benefits with regards to avoiding outages and accelerating network development. The relative price savings from faster curing (such as increasing the speed of connections) or increased durability (potentially reducing operational requirements) will have to be considered internally when compared to the significant price increase in the cost of the materials.

NGET will have to work with their wider supply chain to support the implementation of any novel proposed solutions. As NGET are required to procure a design from suppliers, and cannot take on the role of designer themselves, they will have to work closely with their supply chain to enable the use of novel materials within their network. This could be influenced by factors such as procurement metrics, the collaborative development of required standards and certification, or specific frameworks aiming to encourage the use of novel materials and low carbon solutions.

Based on these conclusions, the following next steps are recommended:

Continue to monitor developments in novel, low-carbon solutions which may help NGET achieve their goals. Novel concrete suppliers face many challenges with creating a business within the construction industry, including a slow adoption curve and high safety and performance concerns. Hence, because of these concerns, supplier availability if highly volatile. Hence, it would be useful for NGET to continually review the supplier space to understand how various companies are performing, including how industry trends are affecting product specifications and attitude to the use of novel materials. Current suppliers which could provide polymer concrete and low-carbon solutions include Sika, Mevocrete and Concretene.

Carry out trials for any novel, low-carbon solutions that are selected. Regardless of the novel material solutions NGET choose to investigate, based on the current state of the standards, it is likely that any novel solutions will require a trial to understand their properties in more detail. Future trials could investigate aspects such as the performance within specific environments, or durability performance from which to understand potential operational cost savings.

Promote understanding across NGET to identify use cases which justify future trials. Based on current understanding of the benefits provided by polymer concretes, there is a lack of an appropriate business case to justify proceeding to a trial. However, following an internal review of this report, further use cases may be highlighted from within NGET which could benefit from the faster curing times provided by polymer concretes. Moreover, through further collaboration with the supplies identified within this report, more beneficial solutions may be found which could benefit from a trial.

Lessons Learnt

The following sections discuss the key findings , structured across the three key metrics identified by NGET. Each section discusses how these findings may impact prospective use cases, primarily capturing discussions held within the workshops.

High compressive strengths could reduce material volumes, and hence costs. Polymer concrete has greater mechanical strengths than traditional concretes and may therefore be required in smaller quantities in some circumstances. This could reduce material volume requirements by up to 10% for certain applications and lessen the impact of the higher cost. However, this is not universally true for all assets. Repair work may need exact amounts to fill cracks or damage, or some assets may have strict weight requirements rather than material strength requirements, necessitating exact amounts.

Polymer concrete may extend asset lifespans and reduce maintenance costs. Due to its probable increased durability when compared to OPC, there is likely a trade-off between higher initial costs and lower long-term operational costs. However, the durability of polymer concretes is not yet proven. Unlike traditional concretes, there are no long-term case studies for polymer concrete assets. Until more evidence is available, the reduced maintenance costs remain uncertain.

NGET may struggle to justify the higher material costs to their supply chain when procuring designs. NGET faces challenges in specifying materials and quantities since the design and construction of assets is carried out by subcontractors who would need incentives to redesign existing plans to incorporate use of polymer concrete, given the higher costs. Our workshops with NGET revealed concerns about specifying designs with less material, as it could shift NGET's role from design acceptor to designer. In addition, the over-specification of designs to incorporate expensive, novel materials would be scrutinised since funding comes from consumer electricity bills. Any design improvements must be justifiable and cost-effective. A further obstacle to wider use of polymer concrete is the current lack of building standards, requiring NGET to de-risk novel material use through trials, adding overall development costs.

Further understanding of polymer concrete properties is needed for decision-making, especially for large projects. This is challenging due to the long-term nature of the effects. NGET workshops highlighted that site-specific conditions significantly impact asset lifespans, and accelerated wear tests may not accurately reflect real-world conditions for polymer concretes. Thus, reduced maintenance costs are likely an emergent benefit rather than a planned one.

Polymer concretes are not a cost-effective way to reduce carbon emissions. HMT Green Book is the government’s guide to investment appraisal, which public investment is judged against. This guidance provides carbon values for value for money assessments, providing an estimate of how carbon emissions should be accounted for in cost benefit appraisals. For 2024 these range from 134 to 403 £/te. Therefore, based off the figures presented, polymer concretes are a very cost-ineffective method of reducing carbon emissions (especially when compared to CEM II equivalents).

The emissions figures used may not be fully accurate when considering additional factors. As highlighted in Section 2 of this report, the carbon emissions metrics do not include transport emissions. However, it is not possible to confirm where the polymer concretes identified are geographically produced, so the actual figure may be higher than reported, thereby reducing the effectiveness of their carbon savings.

Faster curing times may mean the biggest carbon benefit to using polymer concretes is through connecting new power sources. This analysis does not account for the potential benefits of polymer concrete in connecting new renewable power sources to the grid faster than conventional concretes.