Accelerating ultra low-carbon reinforced concrete in railway construction

低碳碱活化胶凝材料（AACMs）具有显著减少混凝土对环境影响的潜力（最多可减少80%的隐含碳）。然而，由于其使用性能的证据基础有限，它们的吸收速度很慢，因此供应商不愿投资增加制造能力。其中一个主要问题是为钢筋混凝土提供长期耐久性数据的钢筋保护水平，特别是在恶劣的环境中。使用无腐蚀的玄武岩纤维增强（BFR）消除了这种风险。在GCRE的现场试验中，bf增强AACM混凝土的演示和性能监测将提供** **适合用途的证据，解决用户/指定者的问题，提供数据以支持标准制定，并鼓励供应链投资于产能。该项目将提供一份可行性研究报告，将AACM/BFR混凝土的最新创新与GCRE混凝土结构的应用结合起来。目标是实施第二阶段项目，在GCRE的优先应用中制造和“安装”使用aacm和BFR制成的混凝土组件，并通过有针对性的测试计划提供支持，以更好地表征和解决大规模使用的技术障碍。我们将以最近的M42国道运输公路项目的知识为基础，利用AACM地聚合物混凝土和玄武岩纤维钢筋的组合，提供最小可行的含碳解决方案，同时通过消除与钢筋相关的腐蚀风险，实现长期耐久性。线性和/或离散式挡土结构将是一个强有力的选择，但也将考虑其他应用。该结构将采用传感技术，使我们能够验证应力与施加载荷和设计预测，并能够在真实世界的风化和疲劳下进行长期性能监测，并最终验证这些新材料系统的性能。所产生的学习将为用户提供信心，并支持标准的制定。它还将使人们能够理解与大规模制造制造相关的挑战，并重新设计供应链，以促进更广泛的采用。可行性研究将由bastechltd（玄武岩纤维增强），Tarmac（使用AACM制造混凝土），Skanska（铁路部门重点建筑承包商），建筑研究机构（包括AACM在内的胶凝材料的耐久性和性能）和国家复合材料中心（结构性能监测，复合钢筋设计支持和可持续性）领导。

Low carbon alkali activated cementitious materials (AACMs) have the potential to significantly reduce the environmental impact of concrete (upto **80% reduction in embodied carbon**). However, their uptake has been slow due to the limited evidence base for their performance in use, with suppliers consequently unwilling to invest to increase manufacturing capacity.One of the main issues is the level of protection afforded to steel reinforcement with long-term durability data needed for reinforced concretes, especially in aggressive environments. The use of non-corroding basalt fibre reinforcement (BFR) eliminates this risk.**Demonstration and performance monitoring** of BF-reinforced AACM concrete in field trials at GCRE will provide **evidence of** **fitness-for-purpose**, addressing user/specifier concerns, providing data to support standards development and encouraging the supply chain to invest in capacity.The project will deliver a feasibility study to **align recent innovations in AACM/BFR concrete with applications for concrete structures at the GCRE**. The objective will be to carry out a Phase 2 project to manufacture and 'install' concrete components made using AACMs and BFR at priority applications at GCRE, supported by a targeted testing programme to better characterise and address technical barriers to use at scale. We will build upon the knowledge from our recent National Highways M42 haul Road project to utilise a combination of AACM Geopolymer concrete and Basalt fibre rebar to offer a minimal feasible embodied carbon solution whilst attaining long-term durability through removal of the corrosion risk associated with steel rebar. Linear and/or discrete ground-retaining structures would present a strong option although other applications will also be considered. The structure/s will incorporate sensing technologies to enable us to verify stress vs applied load and the design prediction and to enable long term performance monitoring exposed to real world weathering and fatigue and ultimately performance validation of these new material systems.**The learning generated will provide confidence** to users and support the development of standards. It will also enable challenges associated with the manufacture of larger scale manufacturing to be understood and supply chains to be reengineered to facilitate wider uptake.The feasibility study will be led by Bastech Ltd (basalt fibre reinforcement), with Tarmac (manufacture of concrete made using AACM), Skanska (rail sector-focused construction contractor), the Building Research Establishment (durability and performance of cementitious materials including AACMs) and the National Composited Centre (structural performance monitoring, composite rebar design support and sustainability).