Mechanical resistance of Pinus radiata CCA treated and face jointed with PVA adhesive
IRG/WP 99-40140
M C Rose, L Reyes, P León
Due to the increased use of Pinus radiata timber composites (laminated structural members, panels, etc), its low natural durability and the toxicity of phenol-formaldehyde type adhesives, a PVA (polyvinyl acetate) adhesive was evaluated in machined and rough CCA treated and untreated face joint samples under DIN 68602 (EN 204-205) standard for groups of requirement 3 and 4. The results showed that the adhesive resisted the face joint in machined samples without CCA treatment. Rough wood samples did not meet the standard. The effect of the CCA treatment up to 4 kg oxide/m3 prior to the bonding produced a decrease in the mechanical strength of the joint in both types of roughness. Treated and machined samples had similar behaviour as rough untreated samples. The selected adhesive is not good in applications on weather exposed service of composites, since in group 3 requirement all samples failed the bending test at the adhesive joint and not at the clean wood portion.
Keywords: POLYVINYL ACETATE ADHESIVE; BONDING STRENGTH; CCA TREATED PINUS RADIATA