TJ.Davis,PA Claisse /Construction and Building Materials 14(00)407-417 Johansen [16]supplemented Trayer's work and devel- 4.Laboratory testing programme oped theoretical equations for predicting the yield load The solid timber was commercially available Euro- me into the load-embedment response ne doweledonThey d that thereood ture the glulam joint samples using a resorcinol-fo correlation between the embedment response and den- maldehyde resin. sity of wood. tec The LVL and PSL structural wood composites wer that have been integrated into current testing standards [22]that were adopted for this research pro crolamTM LVL Grade 2.1E.They are both forms of gramme.Wilkinson compared design strengths based reconstituted wood:Parallam is made from strands of the American design while Mi Intrallam Parallam Glulam Microlam Fig.1.Glulam and the family of structural timber composites produced by TrusJoist MacMillan.T.J. Da¨is, P.A. Claisse rConstruction and Building Materials 14 2000 407 ( ) ]417 409 Johansen 16 supplemented Trayer’s work and devel- w x oped theoretical equations for predicting the yield load and ultimate load of doweled joints that now form the basis of design in EC5 17 . Whale and Smith 18 wx wx extended this work by performing an extensive testing programme into the load-embedment response of doweled joints. They concluded that there was a good correlation between the embedment response and den￾sity of wood. Similar experimental techniques have been employed on a range of investigations 19 w x ]21 that have since been integrated into current testing standards 22 that were adopted for this research pro- w x gramme. Wilkinson compared design strengths based on Johansens’ equations with the American design standard 23 . w x 4. Laboratory testing programme The solid timber was commercially available Euro￾pean WhitewoodrRedwood, visually graded SS C24 to Ž EC5 , obtained from a local timber merchant. Selected, . conditioned, pieces of this wood were used to manufac￾ture the glulam joint samples using a resorcinol-for￾maldehyde resin. The LVL and PSL structural wood composites were both products of the American company TrusJoist w x MacMillan 24 -Parallam PSL Grade 2.0E and Mi- TM crolamTM LVL Grade 2.1E. They are both forms of reconstituted wood: Parallam is made from strands of Douglas Fir or Southern Pine timber bonded together with a phenol-formaldehyde PF adhesive, while Mi- Ž . Fig. 1. Glulam and the family of structural timber composites produced by TrusJoist MacMillan