A Study of Australian Glulam

Abstract

Australia and New Zealand are debating how they should develop a new specification for structural glulam to replace AS/NZS 1328.1:1998. The new document will include i) performance requirements and ii) methods for computing characteristic strength and stiffness properties from lamination data. With respect to item ii) ASTM D3737 and prEN 14080 have been considered as potential models but, it is argued, both are indirect and involve arbitrary assumptions and a series of computational steps that are difficult to justify on a rational basis. Two drafting principles will guide the format of the new standard: it will contain minimal manufacturing prescriptions and the link between the lamination test data and the bending strength of the glulam will involve as little simulation and calibration as possible. Although the testing of both laminations and glulam members has shown that Australian glulam meets the stated characteristic strength and stiffness values listed in AS/1720.1, it is difficult to justify this claim on the basis of lamination test data. The paper addresses those issues and recommends taking an alternative approach to both ASTM D3737 and prEN14080 methodologies in developing a new glulam standard. It is a work in progress at the time of writing.