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论文类型：期刊论文

发表时间：2014-04-01

发表刊物：MATERIALS EXPRESS

收录刊物：SCIE

卷号：4

期号：2

页面范围：177-182

ISSN号：2158-5849

关键字：Cement; Carbon Nanofibers (CNFs); Mechanical Properties; Microstructure

摘要：Carbon nanofibers (CNFs) are considered as a promising candidate for the next generation high performance and multi-functional composites materials of the 21st century for their remarkable properties. In this paper, the mechanical properties of the cement/CNFs composites were analyzed with low concentrations of CNFs at 0.05%, 0.075%, 0.1% and 0.2% by weight of cement at 7, 14 and 28 days. A new surfactant, methylcellulose (MC), was first applied in this CNFs/cement composites research. The results showed that the added CNFs were found to degrade the corresponding flexural strength of cement materials at 7 days, whereas enhanced it at 14 and 28 days. Compared to reference sample, the maximum improvement rate of flexural strength at 28 days is about 21%. However, the compressive strength stayed in a constant stage, and a little deterioration could be found among the CNFs/cement composites. Meanwhile, a crack bridging and fiber-pullout effect was discerned by an ultra-high resolution field emission scanning electron microscopy (FESEM), which ensures load-transfer across voids and cracks. The distribution state of CNFs in matrix was measured by an energy dispersive spectroscopy (EDS) and the given results indicated the embedded CNFs were dispersed well in matrix.