Evaluation of the applicability of the fiber-coating method as a CNTs dispersion technique based on the material properties of FRCC

This study evaluates a fiber coating approach to improve the dispersion of multi-walled carbon nanotubes (MWCNTs) in fiber-reinforced cementitious composites (FRCC) and assesses its applicability based on material properties. Using 1.5 vol.% micro steel fibers (MSF) and 5 wt.% MWCNTs as the baseline, the fiber coating method produced 3.06%, 9.73%, 6.93% and 15.21% higher flow, compressive strength, flexural strength, and electrical conductivity, respectively, than ultrasonic dispersion under the same MWCNTs content, indicating its effectiveness as a MWCNTs dispersion approach. MSF contents of 1.0, 1.5, 2.0 vol.% with fixed (5.0 wt.%) and varied (3.3,5.0,6.7 wt.%) MWCNTs were examined to determine optimal incorporation levels. Relative to the fixed mixture condition, varied mixtures showed a 5.12% decrease in flow at 1.0 vol.% MSF but a 14.12% increase at 2.0 vol.%, while compressive strength, flexural strength, and electrical conductivity increased by up to 17.08%, 18.22%, and 52.47%, respectively. Therefore, an optimal MWCNTs content existed for each fiber volume fraction. • A fiber coating method was proposed to disperse carbon nanotubes (CNTs). • The dispersion mechanism of CNTs via fiber coating was clarified. • Fiber coating enhanced flow, strength, and electrical conductivity compared to ultrasonication. • Optimal CNTs contents (3.3–6.7 wt%) were determined for 1.0–2.0 vol% micro steel fibers.