The effect of adhesive type and bond line thickness on the strength of mortise and tenon joints
Özet
This study was carried out in order to determine the effects of adhesive
type, bond line thickness and moisture content on the strength of
mortise and tenon joints. The polyvinyl acetate (PVAc),
urea-formaldehyde (UF) and animal adhesives were used, combined with
three different bond line thicknesses. At the same time the effect of
the moisture content of the wood was investigated by using wood material
conditioned to 8\%, 12\%, 15\% moisture contents. The results of the
experiments showed that the strength difference between tight fitting
and loose fitting joints was 28\% if animal adhesive was used, 11\% with
UF adhesive and negligible with PVAc adhesive. The effect of the
moisture content of the wood when the joints were assembled did not
depend on the adhesive used. If 12\% is taken as the standard moisture
content, increasing it to 15\% weakened joints by 15\% and decreasing it
to 8\% strengthened them by 6\%, irrespective of the adhesive. Test
results indicate that strongest joints are obtained when a close
tolerance is maintained between the tenon and mortise. (C) 2006 Elsevier
Ltd. All rights reserved.
