Influência de três tipos de tratamentos físicos na resistência à compressão de compósitos cimento-madeira à base de resíduos de serraria

Abstract

In the present research work, the effect of the type of physical treatment in the resistance to compression of composites cement-wood was analyzed. Residues of variegated compositions (hardwood) collected at sawmills of the Metropolitan area of Belém were used, and the effects of the following treatments were studied: drying in stove, thermal bath and the mineralization with aluminum sulfate. The first step of the research was the survey of the theoretical references as support for the experimental program. Next, the constituent materials of the composite were characterized according to methods prescribed by the Brazilian Norms and after being homogenized, lab tests were carried out in the fresh state. The tests in the hardened state were driven in such a way that the mechanical characteristic observed for the evaluation of the effect of the referred treatments was the tensile strength. The results indicated that the used residues inhibit the hydration of the cement matrix, as well as they influence the resistance negatively the tensile strength. The residues treated with drying in stove provided the smallest resistances to the compression observed for the composites; the treatment of thermal bath and the treatment of mineralization presented better results. However, even presenting a slight difference among the medium values for the rupture tensions, they presented statistical equivalence, and they corroborated the statement that the treatment typology used in the residues is preponderant factor to mitigate the harmful effects of the extractives of the wood in the resistance to compression of the mortars.