Propriedades mecânicas de concretos autoadensável produzidos com nanotubos de carbono sintetizados diretamente sobre o clínquer

Abstract

Important research investigations have been developed using nanotechnologyin building materials. Since their discovery, carbon nanotubes (CNTs) have been able to improve composite material properties and this has drawn attention to the use of CNTs in cementitious matrices. Advances in concrete technology have allowed improved behavior in the fresh and hardened states employing new materials and techniques. In this work, self-compacting concretes (SCC) were produced with carbon nanotubes synthesized directly onthe clinker. Part of the cement used in the concrete production was replaced by nanostructured clinker containing different rates of carbon nanotubes (0.5%, 0.75%, and 1% of the cement mass). The workability of the SCC in the fresh state was evaluated and, in the hardened state, the compressive and splitting tensile strength as well as the modulus of elasticity. The behavior of these concretes was compared to a reference SCC, without carbon nanotubes. The results of the SCC investigated by Borges (2019) are also included in the analysis. The evaluation of the test results reveals that the SCC with NTC contents above 0.5% did not show any improvement in mechanical behavior. Besides, the results also show that the best performance of the investigated SCC was achieved for NTC content between 0.3 and 0.5 %.