Graphene enhanced concrete sleeper for lower embodied carbon

在英国，基础设施老化和人口增长正在增加对混凝土的需求，尤其是在铁路部门；那里需要2万英里的新轨道。水泥（混凝土的粘结剂）的生产释放二氧化碳作为CaCO3煅烧的直接副产物。这些直接排放，加上间接过程排放（运输、过程能源等），占全球排放量的8-10%。混凝土行业已经为脱碳做出了大量努力；然而，为了实现英国的气候目标，迫切需要第二阶段更加雄心勃勃的脱碳。该项目愿景通过开发用于承重轨枕的新型石墨烯增强混凝土（GEC）材料，直接解决了这一迫切的脱碳需求。我们的石墨烯添加方法使机械强度提高了50%。此外，混凝土体积的减少、水泥含量的减少以及所需钢筋数量的减少（得益于优越的机械性能）将使总碳足迹减少多达50%。主要目标:1。回顾我们目前的高石墨烯负载外加剂配方，以与轨枕混凝土配合比设计兼容，符合网络铁路标准。2 .确定混凝土枕木中掺合料的最佳掺量（混凝土中石墨烯残留量<0.1wt%）。在第二阶段的睡眠者试验中证明科学，以证明睡眠者应用的好处。虽然其他gec正在开发中，但大多数新兴技术并不适合结构应用。那些以结构应用为目标的GEC产品正在努力克服在水泥中分散石墨烯纳米片（GNPs）的挑战。现有的方法导致过量的空气混入混凝土的微观结构中，严重限制了结构性能。我们已经克服了分散性的挑战，使石墨烯的负载比目前最先进的产品大5倍，分散均匀，没有多余的空气夹带。英国铁路网的基础设施管理公司Network-Rail不包括在赠款财团中，但将是技术的早期采用者，为市场提供了一条明确的途径。此外，我们是制定即将出台的新轨枕标准的指导小组成员，该标准将被重写，以鼓励在轨枕中使用低碳产品。

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.