Compósitos minerais produzidos com matriz de gesso e reforçados com resíduos de algodão (Gossypium herbaceum L.)

Abstract

The research aimed to evaluate the quality of gypsum-based mineral composites reinforced with Eucalyptus grandiswood particles and residues from the cotton crop. The following replacement proportions of eucalyptus by cottonwastewere adopted: 0%, 25%, 50%, 75% and 100% in relation to the total mass of particles. The nominal density was 1.20 g/cm³ and the final dimensions of the composites were 20.0 cm x 20.0 cm x 1.5 cm (length x width x thickness, respectively). Regarding the properties of the composites, it was found that the replacement of eucalyptus by cottonwastedid not change the moisture content or density. On the other hand, there was an increase in the properties of water absorption and swelling in thickness, at both times evaluated, showing a reduction in dimensional stability with the addition of the residue. Regarding the mechanical properties, there was an increase in compressive strength, in addition, an insertion equivalent to 25.17% of cotton wastecan generate a resistance greater than 2.0 MPa as required by the standard. Regarding the modulus of rupture (MOR), there was no significant effect of replacing eucalyptus with cotton waste, but the average value obtained (1.70 MPa) was higher than that stipulated by EN 13279-2 (EN, 2006) for composites of plaster matrix. In general, the composites reinforced with cotton wasteshowed good mechanical resistance, as they met the standards used, but should be used in dry and indoor environments, due to the low dimensional stability.