Title: Effect of different contents of carbon nanotubes on the electrical and mechanical properties of cement paste

Abstract

Cement is a low price and available material, whose properties can be substantially modified with the addition of different reinforcements, so that it can be used in novel applications, such as sensors for structure monitoring, structures for electromagnetic shielding, etc. Among the different available reinforcements, carbon nanotubes give rise to a novel composite material. These nanoparticles can increase the mechanical and electrical properties of the cement, without significantly modifying the weight and the final microstructure of the material. However, the addition of carbon nanotubes to the cement paste changes the viscosity, affecting the workability of the material. In the present study, cement paste was reinforced with different contents of multi-walled carbon nanotubes (MWCNTs). The effect of the reinforcement on the indirect compression resistance, electrical resistivity, density and viscosity were evaluated. The obtained results showed that the MWCNTs modified the hydration process of the cement, so that the material retained a higher degree of humidity at low setting times, which reduces the viscosity of the material. On the other hand, the addition of nanotubes to the cement slightly decreased its density, while the compressive strength and electrical conductivity of the material were increased. The improvement of the conductivity opens these materials the possibility of being used in a higher number of applications related to microelectronics and communications at different environments from building and edification to space.