Preparation of carbon fiber reinforced cement-based composites using self-made carbon fiber mat

• Carbon fiber mat is made using cellulose as the dispersant and the binder.
• Carbon fiber mat is unwoven automatically during mixing to make fibers disperse.
• Good dispersion of carbon fibers is gained in various cement-based composites.

The carbon fiber mat was first manufactured in the laboratory by means of the following procedure: dispersing chopped carbon fibers in the dispersant solution with the concentration of 0.4%, separating carbon fibers from the dispersant liquid using the thin gauze, and depriving the dried fiber mat from the gauze. The mat was then used to prepare carbon fiber reinforced cement-based composites (CFRCs) directly. Once the mat was mixed with water and cement, the adhesion between fibers would fail because of the water-solubility of the dispersant (also worked as the binder in the dry mat), leading to the mat unwoven and fiber dispersion into the cement matrix. To develop this method, different types of dispersant and carbon fibers were combined to prepare carbon fiber mat. Effective dispersion of carbon fibers in cement matrix has been obtained. Further, the applicability of this method has been proved to prepare CFRCs containing coarse aggregate, varying concentrations of carbon fibers, and carbon black. It was shown that the percolation threshold of CFRCs was about 0.6–0.9 vol.%, and CFRCs containing 0.3 vol.% of carbon fibers and not less than 0.6 vol.% of carbon black possessed low resistivity and good mechanical properties.