风机叶片绿色再生纤维钎增强水工混凝土力学性能研究

Mechanical properties of green recycled fibre brazing reinforced hydraulic concrete for wind turbine blades

摘要

【目的】为解决风机广泛使用及其容量不断迭代过程中叶片(玻璃纤维增强聚合物，GFRP)绿色回收和再生利用难题，通过机械加工方法将退役风机叶片制备成纤维钎并验证其应用于水工混凝土中的可行性。【方法】采用宏观、微观和声发射等方法研究不同纤维钎长度、掺量对混凝土和易性、抗压强度、抗折强度和断裂损伤的影响。【结果】结果表明：60 mm长度0.5%体积掺量纤维钎使得混凝土抗压强度最大提升21.35%,而80 mm长度1.5%体积掺量使得抗压性能降低了10.42%;混凝土抗折强度获得了21.93%~105.6%不等的提升；声发射(AE)信号显示随着纤维长度和掺量增加声发射事件数目显著增多，且集中分布于跨中和裂纹附近，同时断裂面不平整、裂缝表现的更为曲折。【结论】风机叶片再生纤维钎与水泥基体机械结合作用较好，能够发挥有效的桥接作用，应用于水工混凝土中的可行性较强，可预见其规模化回收与利用具有较为广阔的发展前景。

Abstract

To address the challenges associated with the green recycling and reuse of blades(Glass Fiber Reinforced Polymer, GFRP) in the widespread use of wind turbines and their continuous capacity iteration processes, decommissioned wind turbine blades were processed into fiber rods through mechanical method, and their feasibility of application in hydraulic concrete was verified. Macroscopic, microscopic, and acoustic emission(AE) method were employed to investigate the effects of different fiber rod lengths and dosages on the workability, compressive strength, flexural strength, and fracture damage of concrete. The result indicate that a 60 mm-long fiber rod with a 0.5% volume dosage maximally enhanced the compressive strength of concrete by 21.35%, while an 80 mm-long fiber rod with a 1.5% volume dosage reduced the compressive performance by 10.42%. The flexural strength of concrete was enhanced by varying degrees ranging from 21.93% to 105.6%. AE signals revealed that the number of acoustic emission events significantly increased with the increase in fiber length and dosage, and these events were concentrated near the mid-span and cracks. Additionally, the fracture surfaces were uneven, and the cracks appeared more tortuous. Therefore, the mechanical bonding between the recycled fiber rods of wind turbine blades and the cement matrix is effective, exhibiting a strong bridging function. The feasibility of their application in hydraulic concrete is strong, and it is foreseeable that their large-scale recycling and utilization hold broad development prospects.

关键词

纤维增强混凝土 / 绿色再生 / 力学性能 / 断裂损伤 / 影响因素 / 风机叶片 / 混凝土 / 声发射

Key words

fibre-reinforced concrete / green recycling / mechanical properties / fracture damage / influencing factors / fan blades / concrete / acoustic emission

基金资助

国家自然科学基金项目(52379127)

青海大学青年基金项目(42162024)