n alignment with National Grid Electricity Transmission’s (NGET’s) objectives of achieving net-zero construction, we aim to evaluate the suitability of polymer concretes as a sustainable alternative to traditional concrete for NGET’s construction operations, appraise their readiness for construction trials, and support NGET in undertaking some of the required trials to demonstrate these materials’ suitability. Earth Friendly Concrete (EFC) has been utilised on the LPT2 (London Power Tunnels 2) project in several areas, but mainly for bulk fill or in temporary works. To further this concrete technology and use EFC more extensively, HMJV in conjunction with its Supply Chain Partners will conduct trials to establish the potential for use in Precast Segmental Lining Elements for the benefit of future projects as part of the LPT legacy.
Benefits
EFC saves 131.5 kgCO2e/m3 of finished product – this material could be used on future National Grid projects, which will help the company reach its net zero target and generate significant interest. Upcoming National Grid shaft and tunnelling projects which could benefit from these EFC C50/60 trials are: West London: Ealing – Laleham (22km) , Iver – North Hyde (15km) and Ealing – Willesden (7km). It is anticipated that EFC will have 40% less emissions/tonne compared to conventional concrete when used across future aforementioned projects. According to the business case, the carbon savings in next 10 years can be 13,187 tCO2e. Apart from carbon savings and wider adoption opportunity, EFC provides enhanced durability, sustainability, and low heat of hydration which is a key parameter when it comes to tunnel temperature and working conditions
Learnings
Outcomes
2024/2025
While there is no immediate impact on the LPT Phase 2 Enterprise, testing EFC has the potential to benefit both National Grid and the broader construction industry. Specifically, EFC could be instrumental in future National Grid cable tunnel projects and other large-scale schemes where ultra-low carbon concrete with appropriate fire ratings is required.
As demonstrated in the data above, using EFC in place of conventional concrete can reduce CO2 emissions by up to 40% per tonne, translating to substantial savings on large-scale projects. For instance, applying EFC to the London Power Tunnels 2 tunnel lining alone would have resulted in a reduction of 7,641,728 kgCO2e. This saving is equivalent to driving an average new car (with exhaust emissions of 114 gCO2e/km) for 67,032,702 kilometres—roughly 1,673 times around the world.
Recommendations for further work
Not Applicable
Lessons Learnt
2024/2025
Lessons learnt from this innovation trial include ensuring that all supplies are available and planning the logistics well in advance of the trials. The team did not encounter any logistical issues regarding the delivery of fire testing panels, the hot box, and other equipment for the trial to the batching plant in Ireland, followed by testing of fire panels in BRE’s (Building Research Establishment) facilities. The only issue was with the supply of fly ash, which caused delays to the programme.
Another lesson learnt is to clarify prior to trials which team is responsible for which resource. This could have avoided any delays with the fly ash.
A positive lesson learnt is the organisation and communication between National Grid, HMJV, and the supply chain, ensuring the design mix was adequate and the successful pre-trials and trials with an experienced team managing the delivery of the project.
Dissemination
None
