Experimental study on mechanical performance of all-softwood pegged mortice and tenon connections

A series of 168 pull-out tests were completed on samples of all-softwood pegged mortice and tenon connections fabricated using carpentry practices common to the UK, USA, Japan and Taiwan. Following testing, the connections were dissected to allow observations of the failure mode and the effects of the end distance in the tenon, edge distance in the mortice, peg diameter and cross-section. Relative stiffness of the peg and the surrounding connection material, determined by geometry, was shown to influence the mode of failure and elastic connection behaviour. For the pegged mortice and tenon connections to perform to their full capacity in the softwood base material, 2d and d end distances are required for connections with 12 and 18 mm pegs, respectively, where d is the diameter of peg. A minimum of 2d edge distance is recommended to prevent wall failure in the mortice and for joints to perform to their full capacity for both 12 and 18 mm pegged connections.