废弃碳纤维混凝土增强机理与功能性研究

碳纤维复合材料在现代工业中大量使用，而使用寿命仅20~25年，今后十几年里将产生巨量碳纤维废弃物，严重污染环境。碳纤维可赋予混凝土自感知等功能，废弃碳纤维混凝土是否也具有优异的功能并不明晰。项目以提升废弃碳纤维混凝土力学性能和导电性能为核心，采用理论分析、数值模拟与实验室试验相结合的方法，围绕废弃碳纤维混凝土增强机理与功能性开展系统研究。考虑废弃碳纤维表面树脂涂层对其与水泥基黏结性能、以及电子在纤维间跃迁行为的影响，探索废弃碳纤维表面改性方法；研究改性废弃碳纤维对混凝土内部微观结构的影响，揭示废弃碳纤维混凝土的增强机理；开展废弃碳纤维混凝土电阻率试验，结合纤维分布状态重构，阐明导电机理；通过废弃碳纤维混凝土的压敏性与电热性试验，明晰废弃碳纤维对混凝土感知性和电热性的影响规律，建立废弃碳纤维混凝土压敏性串并联模型与传热模型。为废弃碳纤维混凝土的工程应用，尤其在结构健康监测中应用提供理论支撑。

Carbon fiber composites are widely used in modern industry and their designed service life is only 20-25 years. A large amount of carbon fiber waste will be produced in the next decade, which will cause serious environmental pollution. Carbon fiber can endow concrete with self-sensing and other functions, but it is not clear whether waste carbon fiber concrete also has excellent functions. This project aims to improve the mechanical properties and electrical conductivity of waste carbon fiber concrete. By combining theoretical analysis, finite element simulation and laboratory tests, the strengthening mechanism and function of waste carbon fiber concrete will be studied systematically. Considering the influence of resin coating of waste carbon fiber on the bond performance between fiber and concrete, and the transition behavior of electron between fibers, the surface modification method of waste carbon fiber will be explored. In addition, the effect of modified waste carbon fiber on the internal microstructure of concrete will be studied, and the strengthening mechanism of waste carbon fiber concrete will be revealed. Furthermore, based on the reconstruction of fiber distribution state and the electrical resistance test, the electrical conduction mechanism of waste carbon fiber concrete will be clarified. Moreover, combined with the compression sensitivity and electrothermal tests of waste fiber reinforced concrete, the effects of modified waste carbon fiber on the perceptibility and electrothermal properties of concrete will be expounded. Finally, the series-parallel model of compression sensitivity and heat transfer model will be established. The research results of the project will provide theoretical support for the engineering application of waste carbon fiber concrete, especially in structural health monitoring.