Caracterização do comportamento mecânico e térmico de argamassas de cimento Portland com adição de nanotubo de carbono

Abstract

Nanotechnology has provided significant innovations in science and engineering. A material that has stood out in this area is the carbon nanotube (NTC). There is recent research applied to the field of construction on the benefits of this material to the mortar in the performance of their mechanical properties and electrical conductivity while little study on thermal conductivity. In this context, this research aims to analyze the mechanical behavior and thermal Portland cement mortars with addition of carbon nanotubes, comparing them with a reference mortar. The CNTs were added to the mortar in the form of dispersion in amounts of 0.20%, 0.30% and 0.50% relative to the cement mass. For the development of the research, it was initially characterized the carbon nanotube through the trials of diffraction x-ray and thermogravimetry (TGA). For mortars in the fresh state, it was determined the consistency index, mass density and entrained air content. The evaluation of the mechanical properties of mortars, was measured by tensile strength tests in flexion and compression. Thermal properties were analyzed by thermal conductivity assay and termogravimentria. Furthermore, additional tests were performed as x-ray diffraction, by water absorption and investigation of the microstructure using electron microstructure (SEM). The mortars with addition of carbon nanotubes, compared to the reference mortar analyzed showed improvements in some properties such as tensile strength in bending and water absorption. The results of the compressive strength and the thermal properties were not significant factor as the scattering of the NTC Portland cement matrix may have influenced these results.