G Nolan

Solid-wood production from temperate eucalypt plantations: a Tasmanian case study

Since 1988, there has been a major focus in Tasmania on research for the management of temperate eucalypt plantations for solid wood. This coincided with the formal transfer of large areas of native forest that had previously been part of the production forest estate into reserves, a decision that triggered the establishment of eucalypt plantations for solid wood. This review summarises research on several key areas: silvicultural requirements for solid-wood production; wood properties of plantation-grown eucalypts and the influence of silviculture and genetics on these properties; factors influencing stem defect and decay; balancing silvicultural requirements with maintenance of tree vigour; and issues concerning wood processing and products. We conclude that there are still operational challenges to be confronted in the production of solid wood from plantations. If these can be overcome in the medium term, temperate plantation eucalypts have the potential to provide wood products that meet the requirements for appearance-grade material and that can compete in the same markets as wood from native forests. The bigger challenge at the national level will be to provide the log volumes of suitable material to meet the anticipated demand 25 to 30 years from now.

Factors influencing the production of structural plywood in Tasmania, Australia from Eucalyptus nitens rotary peeled veneer

Harvested logs supplied from five fibre-managed Eucalyptus nitens plantation coupes with different growing environments were assessed for quality and stiffness. Billets extracted from the logs were rotary peeled for veneer. When averaged across the five coupes, 30% of veneer recovered could be used directly in structural plywood production and an additional 20–25% could be used after further processing. In visual assessment most veneer was assigned an Australian/New Zealand Standard AS/NZS2269.0:2012 Quality D. Acoustic testing during processing showed veneer peeled from a drier and lower elevation coupe had significantly higher dynamic MOE values than veneer processed from logs harvested from wetter higher elevation coupes. To examine the utility of the E. nitens peeled veneer in the production of structural plywood, it was combined with veneer of a known higher stiffness, rotary peeled from regrowth forest Tasmanian oak species logs. Structural seven-ply panels were manufactured from the veneer prepared in three different ply arrangements. Mechanical testing of the panels in accordance with AS/NZS2269.0:2012 showed that an F17 target stress-grade panel product of 83% E. nitens and 17% Tasmanian oak species could be produced, if E. nitens veneer of higher stiffness were selected from veneer segregated by estimated dynamic Modulus of Elasticity value. Panels with 50% E. nitens and 50% Tasmanian oak veneer could be produced by selecting E. nitens veneer of lower stiffness after segregation. In the majority of panels tested stress-grade rating was limited by perpendicular bending strength. Outcomes from the study indicate that structural plywood can be manufactured using differing proportions of E. nitens veneer, rotary peeled from fibre-managed plantations, provided it can be segregated into stiffness categories and selected to achieve a target stress-grade.

Managing risk while translating research outcomes into design and construction innovation

ABSTRACT Significant tension can exist between the goals of architectural research and of architectural and building practice. Worthwhile research involves generating risks its benefits are uncertain and require interpretation in practice as new design approaches or construction methods. In contrast, professional practice generally involves managing building procurement risk. This can encourage participants to resist change and enhance solution reliability, even if this delivers less than optimal performance. Practitioners can be innovative but often only through incremental development, nudging participants along the path to increasingly innovative action. As they do, the capability, capacity and confidence risks associated with novel design solutions need identification, assessment and response. These concepts are discussed in relation to a university-based case study, where researchers joined architectural practitioners in a design team for the design and delivery of a 120-unit student accommodation building. Finished in early 2016, the solution included novel timber-rich prefabrication and assembly techniques.

Comparing the Biodiversity Impacts of Building Materials

Abstract Biodiversity is one aspect of a natural environment affected by the construction of buildings and the manufacture of building materials. However, the complexity of biodiversity impact assessment and the lack of a meaningful surrogate or indicator for biodiversity impacts have made meaningful discussion on constructions impact on biodiversity difficult. This paper reports on part of a multidisciplinary study that examined methods for comparing the biodiversity impacts of different land uses in the life cycle assessment of buildings and building materials. It summarizes the biodiversity impact assessment methods used in recent studies, outlines the major concepts of biodiversity management, expands on the temporal, spatial and other factors that need to be considered when comparing the biodiversity impacts of renewable and non-renewable materials in LCA, and proposes means by which this can be done. It concludes with three qualitative examples of the methods in action.