Carbon nanotubes (CNTs) and titanium dioxide (Titania) nanoparticles are simultaneously incorporated in a cement slurry, and their influence on the mechanical characteristics is investigated. Response surface methodology (RSM) is employed to maximize the strength properties at various incorporation ratios of CNT-COOHs, Titania nanoparticles, and surfactant following the Box-Behnken Design. The morphology and microstructure of the specimens are characterized by XRD, FTIR, and FESEM. According to the experimental results and the ANOVA analysis, it can be concluded that the simultaneous use of Titania nanoparticles and CNT-COOHs significantly enhanced the flexural and compressive strength of cement. The incorporation of Titania nanoparticles displays the most significant effect on compressive strength, mostly due to their nano-filling effect and the preparation of hydration products as nucleation sites. This study also proposes a new, faster and easier, method for the prediction of optimum weight percentages of nanomaterials and surfactants for experimental work.
