Volume 20, Issue 5 (September 1992)
Superposition Theory Applied to Nail/Glue Joints in Wood: Part I—Strength Behavior
A model was developed based on concepts involving superposition of nail and glue joint strength to predict the ultimate load of nail/glue joints in wood subjected to lateral loading. Four combinations of two wood species (lodgepole pine and hard maple) and two nail sizes (6d and 8d) were examined. One brand of commercially-available elastomeric construction adhesive was used. A total of 169 nail, glue, and nail/glue joints were tested to ultimate load. Theoretical predictions based on nail and glue joint strength were compared with experimental data from nail/glue joint tests. The results showed that mean joint strength was predicted to within 9% for three of the four combinations of nail size and wood species studied. Statistical analyses revealed that for these three data sets, mean experimental and theoretical values were indistinguishable at the 0.01 level. In addition, the presence of glue in a nailed joint accounted for a substantial increase in strength over joints without glue.