This work evaluates the influence of three different intensities of refinement of sisal pulp and the effect of accelerated aging cycles on the behavior of composites. Fiber-cements were prepared by the slurry de-watering method and pressing as a crude simulation of the Hatschek process. Mechanical behavior of composites was evaluated by four-point bending test at 28 days, and after 50 and 100 wet/dry cycles. Refinement of pulp and aging have increased the strength and bulk density of composites and decreased the toughness and porosity. The best mechanical performance after aging was achieved for samples with highly refined fibers.
The present work describes non-conventional sisal (Agave sisalana) chemical (organosolv) pulp from residues of cordage as reinforcement to cement based materials. Sisal organosolv pulp was produced in a 1:1 ethanol/water mixture and post chemically and physically characterized in order to compare its properties with sisal kraft pulp. Cement based composites reinforced with organosolv or kraft pulps and combined with polypropylene (PP) fibres were produced by the slurry de-watering and pressing method as a crude simulation of the Hatschek process. Composites were evaluated at 28 days of age, after exposition to accelerated carbonation and after 100 soak/dry cycles. Composites containing organosolv pulp presented lower mechanical strength, water absorption and apparent porosity than composites reinforced with kraft pulp. The best mechanical performance after ageing was also achieved by samples reinforced with kraft pulp. The addition of PP fibres favoured the maintenance of toughness after ageing. Accelerated carbonation promoted the densification of the composites reinforced with sisal organosolv + PP fibres.
Apesar de a obra de Miguel Reale ser conhecida e celebrada em diversos lugares do mundo, seu estudo e referência têm, há algum tempo, restringido-se às disciplinas propedêuticas do ensino jurídico. Esta iniciativa, parte de um exercício para a pesquisa de doutorado da primeira autora, trata de situar, discutir e avaliar a adequação da obra de Miguel Reale para discutir parte da dinâmica da experiência jurídica brasileira que envolve um dos principais atores especializados da cultura jurídica nacional (o Supremo Tribunal Federal) e um dos mais resistentes atores leigos (o movimento indígena pelos direitos à terra e ao território). Neste ponto da pesquisa, o exercício se foca na descrição e debate das ideias de Miguel Reale acerca da experiência jurídica e os desafios encontrados para a proposta de utilizar sua teoria para os fins acima descritos.
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