Carbon Nanotubes (CNT) show extraordinary properties such as high strength and stiffness, the highest among known materials. This is what makes them potential candidates for concrete reinforcement. This paper explores the applicability of CNT in cementitious matrices comparing results derived from high-strength concrete and conventional concrete, as well as conventional concrete. For the execution of this research, and in order to analyze cement mortars with additions when compared to high-strength concrete, different types of CNT have been depicted and selected. After the characterization of different cement pastes obtained, structural elements have been measured. This analysis leads us to the conclusion that the most suitable mechanical strengthening agent for laboratory scale small samples is the use of CNT, since we do not detect significant differences between the structural elements dimensions and high-strength concrete regarding pastes with CNT