Chen Cheng, Li Caiwei, Zhou Yingwu, Sui Lili, Li Xue
Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China.
Shenzhen Institute of Information Technology, School of Traffic and Environment, Shenzhen 518172, China.
Materials (Basel). 2022 Apr 17;15(8):2927. doi: 10.3390/ma15082927.
Under the background of climate change, the steel industry is considered one of the least eco-friendly industries. Flax fiber-reinforced polymer (FFRP) is an emerging sustainable alternative to steel reinforcement bar; however, its application is much restricted due to its interior material properties. This paper proposed a novel way to form closed-shape stirrups with FFRP, which is suitable for replacing steel stirrups. A multi-disciplinary investigation was conducted concerning the structural and environmental performance of FFRP stirrups in reinforced concrete (RC) beams. Seven specimens were tested under a three-point bending load. The FFRP stirrups substantially increased the shear capacity and ultimate vertical displacement by 77% and 74%, respectively, and shifted brittle failure to ductile failure. The closed-shape stirrups avoided the stress concentration and increased the utilization of FFRP tensile capacity to over 80%. Decreasing the spacing of FFRP stirrups effectively increased the shear capacity and ductility; increasing the width or layer of FFRP stirrups improved ductility only. A life cycle assessment (LCA) was later performed to evaluate and compare the environmental performance of steel, FFRP, and carbon FRP stirrups. As compared to carbon FRP and steel ones, FFRP stirrups substantially decreased the global warming and fossil depletion potential by over 60%. The main contributors to the environmental impacts of FFRP stirrups were the heavy metal released into the water and terrestrial environment during the cultivation process.
在气候变化的背景下，钢铁行业被认为是最不环保的行业之一。亚麻纤维增强聚合物（FFRP）是一种新兴的可持续钢筋替代品；然而，由于其内部材料特性，其应用受到很大限制。本文提出了一种用FFRP形成封闭箍筋的新方法，适用于替代钢箍筋。对钢筋混凝土（RC）梁中FFRP箍筋的结构和环境性能进行了多学科研究。七个试件在三分点弯曲荷载下进行了试验。FFRP箍筋使抗剪承载力和极限竖向位移分别大幅提高了77%和74%，并将脆性破坏转变为延性破坏。封闭箍筋避免了应力集中，使FFRP抗拉能力的利用率提高到80%以上。减小FFRP箍筋间距有效地提高了抗剪承载力和延性；增加FFRP箍筋的宽度或层数仅提高了延性。随后进行了生命周期评估（LCA），以评估和比较钢、FFRP和碳纤维增强塑料（CFRP）箍筋的环境性能。与CFRP和钢箍筋相比，FFRP箍筋使全球变暖潜势和化石资源耗竭潜势大幅降低了60%以上。FFRP箍筋环境影响的主要贡献因素是种植过程中释放到水和陆地环境中的重金属。
