Structural behaviour of geopolymer concrete reinforced with basalt FRP bars

混凝土是世界上使用最广泛的建筑材料。普通波特兰水泥（OPC）是一种传统的混凝土粘合剂材料，其生产占全球二氧化碳排放量的8%左右。英国政府已设定目标，到2020年将二氧化碳排放量减少至少34%，到2050年减少80%。此外，钢筋锈蚀是影响钢筋混凝土结构安全性和耐久性的主要问题之一。根据英国交通部的数据，英国每年修复因腐蚀而损坏的钢筋混凝土结构的费用估计为7.55亿英镑。因此，迫切需要为基础设施开发新型的可持续和耐用的RC系统。由无水泥粘合剂制成的地质聚合物混凝土（称为“地质聚合物”，由工业废料制成）作为OPC的替代品，与OPC混凝土相比，可减少60-80%的二氧化碳排放量，并具有更好的性能和耐久性。由于其良好的耐腐蚀性和耐酸性、成本效益、耐高温性等，玄武岩纤维增强聚合物（FRP）棒作为钢筋的理想替代品迅速出现。这就引出了将地质聚合物混凝土和玄武岩FRP筋组合在一个复合系统中以提高钢筋混凝土结构的可持续性和耐久性的全新想法。该项目旨在通过实验和计算方法的结合，全面了解这种复合材料系统的力学行为，以加快其在结构应用中的应用，特别是极端条件下的结构，例如核电厂和沿海结构。这将有助于显著减少二氧化碳排放，RC结构的维修和维护成本。

Concrete is the most widely used construction material in the world. The production of ordinary Portland cement (OPC), a traditional binder material in concrete, accounts for around 8% of global CO2 emissions. The UK government has set a target to reduce CO2 emissions by at least 34% by 2020 and 80% by 2050. In addition, corrosion of reinforcing steel is one of major problems affecting the safety and durability of reinforced concrete (RC) structures. According to the Department for Transport, the annual cost of repairing RC structures damaged by corrosion is estimated to be £755 million in the UK. Thus, it is urgent to develop novel sustainable and durable RC systems for infrastructures. Geopolymer concrete made of a cement-free binder (termed 'geopolymer' and made from industrial wastes) as alternative to OPC offers 60-80% reductions in CO2 emissions and better performance and durability compared to OPC concrete. Due to its good resistance to corrosion and acids, cost effectiveness, high temperature resistance, etc., basalt fibre reinforced polymer (FRP) bar is rapidly emerging as a desirable substitute for steel rebar. These lead to the entirely novel idea of combing geopolymer concrete and basalt FRP bars in a composite system to improve the sustainability and durability of RC structures. This project aims to develop a comprehensive understanding of mechanical behaviour of this composite system using the combination of experimental and computational approaches, in order to expedite its use for structural applications, in particular for structures under extreme conditions, e.g. nuclear power plants and coastal structures. This will help significantly reduce CO2 emissions, repair and maintenance costs of RC structures.