Department of Architecture and Civil Engineering

Fire performance and creep behviour of non-metallic timber connections

At a glance

Funding body: BRE
Supervisors: Pete Walker, Richard Harris, Martin Ansell, Julie Bregula (BRE)
Dates: 2012-2015

Abstract

Non-metallic (GFRP) mechanical connectors offer benefits over current widespread use of metallic connections and glued connections in timber engineering. These include reduced thermal bridging, improved durability, ease of fabrication, ease of recycling on end use and reduced cost. Traditional non-metallic mechanical connections in timber use carpentry techniques such as mortise-tenon joints with timber pegs. Whilst still used in some modern applications, traditional all timber joints suffer from limited strength and comparatively low stiffness. The supervisors at the University of Bath have recently completed a PhD study (Thomson, 2010) which developed a novel non-metallic mechanical connection for structural timber work. This work built on an earlier PhD study completed by Shanks (2005).

The connection uses Glass Fibre Reinforced Polymer (GFRP) dowels and Densified Veneer Wood (DVW) plates. Structural performance has been evaluated under short-term loading and a successful connection design has been developed. The joints have been successfully utilised in a prototype project at the Victoria & Albert museum, but cannot be utilised more broadly in larger scale applications without characterising performance of the connection under longer-term (sustained) loading and assessing performance under fire. The PhD will utilise expertise at the University of Bath in non-metallic timber connection engineering combined with considerable expertise in timber and fire engineering testing at BRE.

The aim of the proposed research project is to further develop non-metallic mechanical connections for structural timber in sustainable construction. Building on previous research work at the University of Bath the project will investigate two specific aspects of performance: long-term time-dependent (sustained) loading; and, performance under short-term fire loading. This aim will be realised through analysis and characterisation of materials and components, experimental evaluation of performance, structural analysis and design refinements. Technical issues to be addressed in this study include structural understanding of experimental performance under complex load cases supported by development of analytical techniques and design methods.