Ca. Eckelman et Jf. Senft, TRUSS SYSTEM FOR DEVELOPING-COUNTRIES USING SMALL-DIAMETER ROUNDWOOD AND DOWEL NUT CONSTRUCTION, Forest products journal, 45(10), 1995, pp. 77-80
Through bolt with dowel nut connectors provide a means of constructing
wood roof trusses from small round wood members. The joint is easy to
fabricate and requires only drilling operations. Trusses constructed
with these connectors could be suitable for housing, farm buildings, a
nd light industrial buildings. Because trusses can be fabricated from
small rapidly grown stems rather than from lumber sawn from old-growth
material, this construction could provide an efficient means of meeti
ng building construction needs, particularly in developing countries.
Tests carried out on through bolts with dowel nut connectors in round,
6- to 7-inch diameter, yellow-poplar (Liriodendron tulipifera) specim
ens gave axial strength values that ranged from a low of about 6,000 p
ounds to a high of over 30,000 pounds. Results were strongly affected
by splits in the wood. Proper placement of dowel nuts to avoid splits
substantially affected strength results. Reinforcing the ends of split
members with a wrap of strapping steel substantially improved strengt
h.