GRAPHene enhanced pre-CAST concrete (GRAPHcast)

预制混凝土比现场混凝土浇筑更经济实惠，可控，安装更快，符合英国政府促进场外制造/模块化建设的雄心。[1\]然而，今天的预制混凝土混合物带来了许多挑战：1\。水泥（混凝土的粘合剂）的生产是高碳密集型的（860 kgCO2e/吨）[2]。达到设计强度所需的水泥含量使预制混凝土具有较高的碳足迹（256 - 329kgCO2e/cu. m），尽管使用了水泥增强剂。水泥替代品延迟固化/强度发展（16小时脱模，14天安全运输），限制了生产率，并有在处理/储存期间损坏的风险。钢筋增强了早期强度，但增加了产品成本和碳排放。Nationwide-Engineering-Research-and-Development-Ltd（NERD）的石墨烯增强混凝土（GEC）专利外加剂CONCRETENE此前已开发用于预拌混凝土领域，石墨烯的增强效果可以减少水泥含量，或与传统普通硅酸盐水泥（OPC）相比减少混凝土体积。或增强材料混合物（例如CEM-III）。这些材料节省带来了显著的碳足迹减少（减少高达30%）。除了脱碳，混凝土还能加速强度发展/缩短固化时间（例如，在I-UK：99366，220吨混凝土板在24小时内达到28天的设计强度）。因此，CONCRETENE非常适合解决预制行业的主要挑战，但首先需要重新配制，以满足预制件与预拌件更复杂的化学和生产需求。GRAPHCAST项目是CONCRETENE开发商NERD和Roger-Bullivant-Ltd（RBL）之间的合作，Roger-Bullivant-Ltd（RBL）是国际Vinci集团的一部分，该集团合并了Soletanche-Bachy，建筑基础领域的世界领导者，在60个国家开展业务。除了NERD迭代的CONCRETENE重新制定外，RBL的测试，放大和现场试验将评估住宅建筑和低层结构的预制桩和梁的性能。最后，通过在现场施工现场验证性能，GRAPHcast将为混凝土的快速商业化铺平道路。虽然预制混凝土的市场比预拌混凝土小（因此对私人投资者的吸引力较小），但在短期内更容易开发，因为销售可以利用RBL完善的销售网络，而不是依赖NERD直接向个别公司销售。[1\]建设-剧本：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

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