Comportamento de cimento Portland fabricado com micro e nanoestruturas de carbono sintetizadas diretamente sobre escória de alto-forno

Abstract

Cement is the most widely used building material in the world; however, it consumes a lot of energy and releases a significant amount of carbon dioxide (CO2) in the atmosphere during its manufacture. Cement composites (paste, mortar and concrete) have satisfactory compressive strength but lower tensile strength and ductility. Thus, the use of micro and nano-structured carbon materials, which have high tensile strength, in cement composites has been investigated to increase even further their applications in the construction industry. In this scenario, this study analyzes the production and characterization of Portland cement manufactured with micro and nano-structured carbon materials synthesized directly over blast furnace slag on rotary and stationary process. The synthesis products were characterized by scanning (SEM) and transmission electron microscopy (TEM), thermogravimetric analysis (TG), and for Raman spectroscopy. Mortars were prepared with cement CP III-E-40 containing micro and nano-structured carbon materials in a content of 0.1 and 0.3% with respect to the cement mass. Uniaxial compressive strength, static secant modulus of deformation static and splitting tensile strength of the mortars were evaluated in the ages of 7, 28 and 56 days. A reference mortar without the micro and nanostructured carbon material was also produced and analyzed for comparison. The results show that mechanical strength and static secant modulus ofdeformation static of the mortars was unchanged with the addition of the micro and nano carbon structures. Already the micrograph of the mortar made at different times indicates changes in its microstructure.