纳米碳纤维改性混凝土的力学性能及微观机理

采用不同掺量的纳米碳纤维制备混凝土,测试了纳米碳纤维改性混凝土的抗压强度、抗折强度和劈拉强度,并对其改性机理进行了探究。结果表明,适量的纳米碳纤维能够提高混凝土的力学性能。当掺量为0.3%时,纳米碳纤维改性混凝土的力学性能最优,其抗压强度、抗折强度和劈拉强度相较于素混凝土分别提高了9.2%、13.2%和17.5%。SEM测试结果表明,纳米碳纤维能够在混凝土内部形成立体网状结构,改善混凝土的微观形貌特征,增强混凝土的韧性和整体性,填充混凝土内部的孔隙缺陷,细化孔径分布,消耗混凝土破坏时的部分断裂破坏能。

Mechanical Properties and Micromechanism of Concrete Modified by Carbon Nanofibers

Carbon nanofibers modified concrete was prepared with different dosage of carbon nanofibers. The compressive strength, flexural strength and splitting strength of the concrete were tested, and the modification mechanism was explored. The results show that the appropriate amount of carbon nanofibers can improve the mechanical properties of concrete. When the content of carbon nanofibers is 0.3%, the carbon nanofibers modified concrete has the best mechanical properties, among which the compressive strength, flexural strength and splitting strength are increased by 9.2%, 13.2%and 17.5% respectively compared with those of plain concrete. The SEM results show that carbon nanofibers can form a three-dimensional network structure inside concrete, thereby improving the micro-morphology of concrete, enhancing the toughness and integrity of concrete, filling the internal pore defects inside concrete, refining the pore diameter distribution,and consuming part of the fracture energy of concrete when it is destroyed.