Development of connection systems for timber and bamboo

Bamboo has many advantages as a construction material: it is a rapidly renewable sustainable resource and has mechanical properties similar to timber. Worldwide, there is a growing interest in the development of bamboo products as a sustainable, cost-effective and ecologically responsible alternative construction material (De Flander 2005, Sinha et al. 2013, Sharma et al. 2015).
Increasing research demonstrates a growing industry and demand for sustainable building products. Engineered bamboo composites are of particular interest due to the standardisation of shape and the relatively low variability in material properties. While the potential of bamboo is promising, more widespread development and use of bamboo is hampered by the lack of engineering data for mechanical properties and appropriate building codes (Sharma et al. 2015). This includes limited connection testing data available in the literature as well limited use of laminated veneer bamboo (LVB) for reinforcing timber elements (Kaboli and Clouston 2019).
The only code in the world to contain any guidance on bamboo connection design is the Colombian NSR10 (AIS, 2010); however, the guidance is only relevant for bolted connections of culms (bamboo stems) filled with mortar. In a recent study based on my Msc project, design formulas were postulated for basic properties of dowel-type connections in round bamboo, including self-tapping screws (Trujillo and Malkowska 2018); however these only included embedment strength and withdrawal capacity of screws.
This PhD will aid the development of a connection theory, which is deemed necessary to enable the safe use of bamboo in its natural and engineered form. Models that predict numerically the behaviour in terms of strength and stiffness will be developed. These models will generally take the form of mathematical expressions and will reliably predict the strength of a given connection when certain readily measurable parameters are considered through non-destructive means (e.g. density, geometry, moisture content, fastener properties). Connections addressed will include metal fasteners as well as adhered connections between glulam and bamboo.