Compósitos com fibras de sisal e caroá com licor pirolhenoso em matriz cimentícia com metacaulim.

Abstract

In the search for alternatives that aim to reduce production energy and environmental impacts, research has again given emphasis to vegetable fibers in composites, as they are materials considered less expensive and of renewable origin, when compared to synthetic fibers. The progress of research and development of new technologies, in this sense, are necessary to obtain a material that meets the requirements of the market, functionality and environmental issues. The analysis becomes more complex when considering the relationship between the fiber and the matrix due to the large number of factors that interfere in this interaction between the matrix, fiber, processing form and interface. Based on the above, it was decided to use caroá (Neoglaziovia variegata) and sisal (Agave sisalana) fibers, which are species widespread in the Northeast Region, generating direct and indirect jobs in their production chains. Thus, the objective of this work was to analyze the development of a cementitious composite reinforced with a 1% content of vegetable fibers treated with pyroligneous liquor, aiming at the structural reinforcement and a greater longevity of the composite and the fiber-matrix interaction. The composites were mechanically characterized by means of three-point bending tests, tensile tests by uniaxial compression and physically by means of the water absorption test, in addition to thermal, XRD and morphological analyses. The fibers were characterized using physical and mechanical tests. The microscopy results indicate that the treatment provided greater cleaning on the surface of the fiber, reducing the hydrophilicity and preserving the integrity of the fiber in the composite. On the other hand, the mechanical tests indicated that for the three-point bending test there was a reduction in the strength of the treated sisal fibers while the caroá fibers showed an increase in strength, while for the axial compression test the untreated fibers obtained better results. In the thermal characterization the untreated fibers obtained better results for the thermal conductivity. In the XRD, the fibers impregnated with pyroligneous liquor obtained a higher crystallinity index.