Utilization of Silica Fume to Stabilize the Dispersion of Carbon Nanofilaments in Cement Paste

Abstract

The incorporation of carbon nanofilaments in cementitious materials has been researched extensively in the past decade. However, the poor dispersibility of these filaments remains a hurdle to harnessing their exceptional properties. This work presents a method for enhancing the dispersion of carbon nanofibers (CNFs) in cementitious matrices. The method incorporates silica fume to stabilize the distribution of CNFs in fresh cement paste. The investigations show that this method is significantly more effective than similar approaches. To examine the effectiveness of the method, specimens of CNF incorporated cement paste with different concentrations of silica fume were produced and imaged by optical microscopy. Using a novel dispersion quantification method, the dispersion values of CNFs in the specimens were measured and compared. The results show that silica fume, if used in sufficient proportions, can largely prevent the reagglomeration of CNFs in fresh cement paste, and thereby stabilize their dispersion.