Public Funding for Nationwide Engineering Research and Development Ltd

Pre-cast concrete is more affordable, controllable, quicker-to-install than onsite concrete-casting and aligns with UK Govt ambition to promote off-site manufacturing/modular construction.\[1\] However, today's pre-cast concrete mixes pose numerous challenges: 1\. The production of cement (concrete's binding agent) is highly-carbon-intensive (860kgCO2e/tonne)\[2\]. 2\. The cement content required to reach design strength gives pre-cast concrete a high carbon footprint (256-329kgCO2e/cu.m), despite using cement replacements. 3\. Cement replacements retard curing/strength-development (16-hour-demoulding, 14-day safe-transport), limiting productivity and risking damage during handling/storage. 4\. Steel reinforcement enhances early-age-strength but increases product-cost and embodied-carbon. Nationwide-Engineering-Research-and-Development-Ltd(NERD)'s patented Graphene-Enhanced-Concrete(GEC) admixture, CONCRETENE, has been previously developed for the ready-mixed concrete sector, where the strength-enhancing effect of graphene enables reduced cement-content, or reduced concrete-volumes compared to traditional Ordinary-Portland-Cement(OPC), or replacement-material blends (e.g.CEM-III). These material-savings deliver a significantly reduced carbon-footprint (up to 30% reduction). In addition to decarbonisation, CONCRETENE accelerates strength-development/reduces curing time (e.g. 220-Tonne CONCRETENE slab reached 28-day design strength in just 24-hours in I-UK:99366). CONCRETENE is therefore ideally suited to address the major precast sector challenges, but first needs to be reformulated to meet the more complex-chemistries and production-demands of precast vs ready-mixed. The GRAPHcast project is a collaboration between CONCRETENE developers, NERD, and Roger-Bullivant-Ltd(RBL), part of the international Vinci-Group that incorporates Soletanche-Bachy, world-leader in building-foundations, with operations in 60 countries. Alongside iterative CONCRETENE reformulation by NERD, testing, scale-up, and site-trials by RBL will assess performance in precast piles and beams for residential-buildings and low-rise structures. Finally, by validating performance on a live-construction site, GRAPHcast will pave the way for rapid commercialisation of CONCRETENE. Although precast is a smaller market than ready-mixed concrete (and therefore less attractive to private-investors), it is easier to exploit in the short-term, since sales can leverage the well-established sales-network of RBL, in contrast to relying on NERD making direct-sales to individual companies. \[1\]Construction-Playbook:https://www.gov.uk/government/publications/the-construction-playbook \[2\] ICE: https://www.ice.org.uk/media/200i0yqd/2022-04-26-low-carbon-concrete-routemap-final\_rev.pdf

Direct-emissions from cement calcination (CaCO3-\>CO2+CaO), combined with concrete-related process-emissions (transport, process-energy etc), represent \>7% of global emissions. NERD's patented Graphene-Enhanced-Concrete (GEC), CONCRETENE(r), offers a pathway to mass-decarbonisation of the concrete-sector, but large-scale exploitation is currently blocked by material-manufacturing and supply-chain challenges. The **GRAPHenhance project vision** is to address these challenges to unlock CONCRETENE's decarbonisation potential. CONCRETENE is a graphene-enhanced admixture for concrete, engineered to enhance performance and sustainability, and the first GEC to reach commercial-scale pilots globally. The technology allows for reduced concrete volume and cement content to achieve equivalent structural performance, delivering significantly reduced carbon footprint (up to 30%) vs OPC. The key to CONCRETENE's performance is the dispersion of Graphene-Nanoplatelets(GNPs) within the material structure. This dispersion is stabilised using Graphene-Oxide(GO) (secondary graphene-component), which prevents GNP aggregation, enables graphene(GNP+GO) loading of 3-6% (~5x higher graphene-concentration than state-of-the-art), and provides a second mechanism of strength-enhancement (see Appendix\_Q3). Although other GECs are in development, most are non-structural. The few structural-GECs in development have so far failed to overcome the GNP-dispersion challenge. Existing approaches result in the incorporation of excess-air, reducing structural-performance and longevity. No other GEC in-development uses the GO-stabilisation approach patented by NERD. GO supply currently represents a major bottleneck to CONCRETENE commercialisation. NERD currently source from China, presenting challenges including batch-to-batch variability (sp2-carbon-speciation up to 4%-variance, sp3-carbon-speciation up to 8%-variance, sulfur-containing-species up to 1.6%-variance), price-volatility, and import-tariffs. Similarly, NERD source GNP from Canadian Black-Swan-Graphene(BSG) via their UK-based partner-organisation, Thomas-Swan(TS), but the current product is not optimised for CONCRETENE, and needs to be scaled-up (in the UK) to meet future-demand. **GRAPHenhance** will pave-the-way for upscaled UK nanomaterial production-capacity, with a **main-focus** on GO (manufacturing by William-Blythe) and GNPs (manufacturing by Thomas-Swan) tailored to CONCRETENE's requirements. GRAPEHhance will overcome challenges relating to NERD's GO and GNP supplies (batch-to-batch variability, residual-surfactants) to finalise CONCRETENE's supply-chain and material composition- prerequisites to accreditation and large-scale commercialisation. **Key objectives**: * To optimise UK-supply of GNP * To determine GO-specifications, enabling post-project negotiation for a commercial-supply agreement between WB and NERD * To validate performance of manufactured GO and GNP in CONCRETENE with graphene-loading at 3-6% * To validate the resulting CONCRETENE formulation in an industrial-pilot (transport-sector) against standard durability testing (ATSM\_C642/C1293/C452/C1138) **GRAPHenhance** partners: * **Nationwide-Engineering-Research-and-Development(****NERD****)**: SME, owner of CONCRETENE technology. * **William-Blythe(WB)**: Leading chemicals innovator, part of Synthomer Group (FTSE-250). * **Thomas-Swan(TS)** (supported by Black-Swan-Graphene(BSG))**:** Speciality-chemicals manufacturer, developer of GNP IP (IP owned by BSG).

In the UK, ageing infrastructure and population growth are increasing demand for concrete, not least in the rail sector; where 20,000 miles of new track are needed. The production of cement (concrete's binding agent) releases CO2 as a direct by-product of CaCO3 calcination. These direct emissions, in combination with indirect process-emissions (transport, process energy etc), represent a staggering 8-10% of global emissions. The concrete sector has undertaken substantial efforts towards decarbonisation already; however, a second-phase of more ambitious decarbonisation is urgently needed in order to meet UK climate targets. This project vision directly addresses this urgent decarbonisation need through the development of novel graphene-enhanced concrete (GEC) materials for load-bearing sleeper applications. Our method of graphene dosing delivers a 50% improvement in mechanical strength. In addition, a combination of reduced concrete volume, reduced cement content and reduction in amount of steel reinforcement needed (thanks to the superior mechanical performance) will reduce total carbon-footprint by up to 50%. Key Objectives: 1. To review our current admixture formulations with high graphene loading for compatibility with sleeper concrete mix designs, prescribed to Network Rail standards. 2. To define optimum admixture dosing into concrete sleepers (with graphene content of concrete remaining <0.1wt%). 3. Prove the science in sleeper trials at Phase 2 stage to demonstrate the benefits for sleeper applications. Whilst other GECs are in development, most emerging technologies are not suitable for structural applications. Those GEC products that aim to target structural applications are struggling to overcome the challenge of dispersing graphene nano-platelets (GNPs) within cement. Existing approaches result in the incorporation of excess air into concrete's microstructure, severely limiting structural performance. We have overcome the dispersion challenge, enabling 5x greater graphene-loading than the state-of-the-art, with uniform dispersion, and no excess air entrainment. Network-Rail, infrastructure manager of the UK rail-network, are not included in the grant consortium, but will be early technology adopters, providing a clear route to market. In addition, we are on the steering group for the development of the forthcoming new sleeper standard, which will be re-written to encourage low embodied carbon products to be used in sleepers.