- Abstract Nanotubes are considered as promising nano-reinforcement in cement-based materials. The main challenge towards achieving a significant enhancement in cement properties is an effective dispersion of the agglomerated nanotubes. In this paper, we demonstrate a novel dispersion method of Tungsten di-Sulfide NanoTubes (WS 2 NTs) that results in substantial flexural and compressive strength enhancements at optimal nanotube concentration as low as 0.15 wt%. The reinforcement by WS 2 NTs remains significant after a variety of curing processes, suggesting a genuine nanoscale reinforcing effect. Finally, by employing a comprehensive fractography we found that the WS 2 NTs inhibit crack propagation by bridging with a pullout failure mechanism.