PERFORMANCE OF TWO TYPES OF CEMENT IN PRODUCTION OF CEMENT BONDED WOOD PANELS COMBINED WITH RICE HULL

The objective of this study was to evaluate the performance of two types of cement in the manufacturing of cement bonded wood panels with addition of rice hull. Sealers used were cement V-ARI (CP V) and cement Portland IV, pozzolanic (CP IV). Proportions adopted in the composition of panels were 0, 50 and 100 % rice hulls combined with 100, 50 and 0% of wood particles. Species used in this study were  Eucalyptus grandis  and  Pinus elliottii . Parameters considered to evaluate panels were the mechanical properties. CP IV did not cure with the addition of pine particles in any proportion. The values of modulus of rupture (MOR) were higher with CP IV, but with the addition of rice hulls they decreased. CP V shoved higher internal bond strength in all proportions studied. Addition of rice hulls decreased all the mechanical properties studied in this work, therefore its use in cement bonded wood panels must be controlled, larger quantities than 50% of total vegetal mass weight are not recommended. Using Bison process as a reference, CP IV presented the necessary requirements to be used in cement bonded wood panels. Keywords :  Eucalyptus grandis ; CP IV; CP V-ARI; agricultural waste.