Shi Tao, Li Kunming, Shao Sijie, Cai Xuanfeng, Wang Xinpeng, Pan Chonggen, Fu Ning, Wang Haibo
College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China.
Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Zhejiang University of Technology, Hangzhou 310023, China.
Materials (Basel). 2025 Mar 28;18(7):1532. doi: 10.3390/ma18071532.
Recycled carbon fiber, as a novel type of solid waste, possesses high tensile strength, structural stability, and low utilization rates. Recycling carbon fiber for use in cementitious materials presents an efficient solution. However, achieving good interfacial bonding between recycled carbon fiber and cementitious materials is crucial for its high-performance application in such materials. This study first characterizes the properties of recycled carbon fiber and, for the first time, tests the interfacial parameters between recycled carbon fiber and cement matrix through single-fiber pull-out tests. The results show that the surface of recycled carbon fiber, lacking active functional groups and being relatively smooth, leads to poorer interfacial bonding with the cement matrix compared to virgin carbon fiber. The interfacial bonding strength, interfacial friction bonding strength, and chemical debonding energy are 0.65 MPa, 0.47 MPa, and 0.36 J/m, respectively. Next, based on the theoretical model of interfacial mechanics, a single-fiber pull-out model was used to predict the bridging stress curve of recycled carbon fiber. The calculations show that the bridging stress of recycled carbon fiber at volume fractions of 0.16%, 0.3%, and 0.47% are 1.25 MPa, 2.18 MPa, and 3.40 MPa, respectively. Finally, tensile tests were conducted to investigate the tensile properties of cementitious materials reinforced with recycled carbon fiber. At various fiber contents, the recycled carbon fibers provided corresponding bridging stresses at crack sites, enhancing the tensile strength of the cementitious materials by 8.8~35.48%.
再生碳纤维作为一种新型固体废弃物，具有较高的拉伸强度、结构稳定性，但利用率较低。将再生碳纤维用于水泥基材料是一种有效的解决方案。然而，要使再生碳纤维在水泥基材料中实现高性能应用，关键在于实现其与水泥基材料之间良好的界面粘结。本研究首先对再生碳纤维的性能进行了表征，并首次通过单纤维拔出试验测试了再生碳纤维与水泥基体之间的界面参数。结果表明，再生碳纤维表面缺乏活性官能团且相对光滑，与原始碳纤维相比，其与水泥基体的界面粘结较差。界面粘结强度、界面摩擦粘结强度和化学脱粘能分别为0.65MPa、0.47MPa和0.36J/m。其次，基于界面力学理论模型，采用单纤维拔出模型预测了再生碳纤维的桥联应力曲线。计算结果表明，再生碳纤维在体积分数为0.16%、0.3%和0.47%时的桥联应力分别为1.25MPa、2.18MPa和3.40MPa。最后，进行了拉伸试验，以研究再生碳纤维增强水泥基材料的拉伸性能。在不同纤维含量下，再生碳纤维在裂纹部位提供了相应的桥联应力，使水泥基材料的拉伸强度提高了8.8%~35.48%。
