Abstract:

Wind power has become a cornerstone of modern energy systems. Upon retirement of wind turbine generator, the recycling of discarded wind turbine blades (WTBs) presents a challenge due to their difficulties in crushing and decomposing. It is necessary to explore a sustainable pathway to recycling waste WTBs within the realm of green economy. For the dominated materials of fiber reinforced polymer (FRP) in wind turbine blades, this review summarized the strategies and primary methods for the utilization of waste WTBs, and introduced briefly the advantages and disadvantages on mechanical, thermal and chemical methods. Due to the low values of the components in the waste WTBs, the existing recycling methods were lack of a substantial economic benefits without government subsidies or disposal costs from the waste-producing firms. Therefore, the mechanical methods with a simple process recycling the waste WTBs for construction materials reinforcement should have a promising economic benefit and application prospect. This review summarized the research progress of FRP materials from waste WTBs being used as the reinforcing agent in concrete, cement mortar and geopolymer. The FRP materials from waste WTBs can provide construction materials excellent tensile and flexural stress even after fracture. However, there were issues with the inadequate bonding strength between the FRP material and cement, and the FRP material reduced the density of construction materials, potentially leading to a decrease in compressive strength. Further research should focus on improving the bonding strength between FRP materials and cement, and optimizing size of FRP materials and its blending ratio to enhance the overall performance of construction materials. In general, the blending ratio of FRP materials should be kept in a suitable and low level to ensure the strength of construction materials. The huge amount of construction materials, such as concrete and cement mortar, can consume the waste WTBs even with a very low blending ratio.

Key words: waste wind turbine blades, reinforced fiber, concrete, cement mortar, geopolymer

摘要：

风力发电已成为了现代能源体系的主要支柱。风力发电机组退役后，废旧风电叶片因难破碎、难降解等面临资源化难题，亟需探索绿色经济的资源化路径。针对当前以玻璃纤维增强树脂基复合材料（fiber reinforced polymer，FRP）为主的风电叶片，本文概述了风电叶片梯次利用的策略和主要方法，简要介绍了机械法、热法和化学法等方法的工艺特点和优劣势。由于叶片中缺乏高价值组分，现有回收方法如无政府补贴或产废单位承担处理费用，均较难产生可观的经济效益。因此，工序简单的机械法回收废旧叶片用于强化建筑材料具有较好的经济效益和应用前景。本文重点总结了废旧风电叶片FRP材料作为混凝土、水泥胶砂和地质聚合物等建筑材料增强剂的研究进展。废旧叶片FRP材料可为建筑材料提供良好的抗拉和抗弯应力，断裂软化后仍可通过桥接作用转移应力，从而实现对建筑材料的强化。但FRP材料与水泥界面区域的结合强度不足，且FRP材料降低了建筑材料的密度，可导致建筑材料抗压强度下降。进一步研究应重点改善FRP材料与水泥的结合强度，优化掺杂比例和FRP材料尺寸，以提高建筑材料的整体性能。总体而言，废旧叶片FRP材料的掺混比例不宜过高，才能保证建筑材料的强度，但混凝土、水泥胶砂等建筑材料用量极大，极小的掺混比例既可完全消纳废旧叶片。

关键词: 废旧风电叶片, 增强纤维, 混凝土, 水泥胶砂, 地质聚合物