BENDING PROPERTIES OF NAIL-LAMINATED HARDWOOD POSTS

Structural properties and constructability factors of yellow poplar an d red maple nail-laminated spliced and unspliced creosote-treated and untreated construction posts were determined Mean modulus of elasticit y (MOE), modulus of rupture (MOR), and ultimate moment values for sing le members of each species were also determined. Design values were de veloped from the lumber properties of the single members and compared with published values. Both yellow poplar and red maple nail-laminated posts were successfully fabricated with a commercially available pneu matic nailer using 20d galvanized wire nail fasteners and operating pr essures less than 690 kPa (100 psi). Unspliced posts were tested accor ding to ASTM D198-84, and compared to properties of single members. Tr eated and untreated spliced posts were tested according to ASTM D198-8 4 and initial stiffness and moment capacity values of posts were compa red to unspliced post values. Splicing reduced the initial stiffness a nd ultimate bending strength of yellow poplar posts by 69% and 47%, re spectively. Similarly splicing reduced the initial stiffness and momen t capacity of red maple posts by 73% and 62%, respectively. initial st iffness and moment capacity values of untreated and creosote-treated p osts were not signifcantly different at the 5% confidence level.