Compósitos à base de cimento e gesso reforçados com partículas de madeira de Eucalyptus grandis

Abstract

The objective of this study was to produce and evaluate physically and mechanically composites of plaster-wood and cement-wood using particles of Eucalyptus grandis, in order to analyze the possible replacement of the cement by the gypsum as a binder, in order to reduce the cure time. The panels were produced in metal molds with dimensions of 25 x 25 x 1,5 cm (LxLxA), nominal density of 1,2 g. cm- ³ and a ratio of 1:2,75 (wood: plaster) and water-plaster of 1:0,4. Reference panels were produced using the CP V-ARI Portland cement as a binder. Calcium chloride (CaCl²) was used as the catalyst to accelerate hydration. The results indicated that the panels did not show significant statistical differences in density, water absorption and swelling in thickness both after 2 and 24h of immersion in water, modulus of elasticity for flexion and parallel compression. The cement-wood panels obtained higher values in moisture retention, modulus of rupture for static bending test and internal bonding. These results demonstrate that the use of gypsum as a binder may be feasible and further studies on the loss of mechanical resistance of gypsum in contact with moisture are required.