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Indexed by:期刊论文

Date of Publication:2013-10-01

Journal:NANOSCIENCE AND NANOTECHNOLOGY LETTERS

Included Journals:SCIE、EI、Scopus

Volume:5

Issue:10

Page Number:1112-1118

ISSN No.:1941-4900

Key Words:Carbon Nanofibers (CNFs); Cement-Based Materials; Mercury Intrusion Porosimetry (MIP); Microstructure; Porosity; Composites

Abstract:In this present work, mechanical properties and microstructure of carbon nanofibers (CNFs) reinforced cement-based materials were analyzed. CNFs were added into cement matrix in concentrations of 0.075%, 0.1% and 0.2% by weight of cement with a water to cement ratio of 0.35. Ultrasonic processing and a commercial surfactant were utilized to achieve homogenous CNF suspensions. Mechanical properties of the newly formulated cement/CNFs composites were analyzed, and the results show that the CNFs improve the flexural strength and compressive strength. Mercury intrusion porosimetry (MIP) was used to characterize the porosity and the pore size distribution of cement/CNFs composites. Meanwhile, an ultra-high resolution field emission scanning electron microscopy (FE SEM) and an energy dispersive spectroscopy (EDS) were used to discern the microstructure of cement matrix incorporating CNFs. Compared to a plain sample, the porosity of cement incorporating 0.075 wt% and 0.1 wt% CNFs decreases, whereas that of 0.2 wt% mixes increases. A lower porosity closely corresponds to a higher mechanical performance in cement matrices. Moreover, the added CNFs concentrated pore size distribution of the mixes. The embedded CNFs act as bridges and networks across the voids and cracks in matrix, which guarantees load-transfer in case of tension.