Experimental performance of non-metallic mechanically fastened timber connections

The use of glass fibre reinforced polymer dowels and densified veneer wood plate is proposed as a contemporary means of providing a non-metallic mechanically fastened timber connection. From fabrication to end of life, the use of mechanically fastened non-metallic connections has the potential to offer many benefits to the field of timber engineering. Currently metal free glued joints provide corrosion resistance and, when made with thermosetting resins, are safer in fire than using metallic mechanically fastened connections. However, glued joints are restricted by a requirement for strict quality control in fabrication, which adds expense. In response to this, the use of non-metallic components to provide a mechanically fastened metal free connection has been investigated. This paper presents results from a series of parallel to grain tensile connection tests in glued laminated timber. Nonmetallic dowels can be more closely spaced than metallic dowels and in terms of connection capacity per unit connected area, it is demonstrated that the proposed connection type has the potential to exceed the efficiency of metallic counterparts. Based upon the test results presented, recommendations are given for fastener spacing design parallel to grain and design analysis of this new connection system is discussed.

Andrew Thomson, MEng

Richard Harris, BSc, CEng, FIStructE, MICE, FIWSc

Martin Ansell, BSc, PhD, FIMMM, FISWSc

Pete Walker, BSc, PhD, MIEAust, CPEng