Strength prediction of recovered softwood beams for structural reuse

In order to help reduce society's impact on the environment, the research described in this paper considers the reuse of structural softwood members recovered from demolished buildings. Unlike aluminium, concrete or steel which are produced within a quality control system, softwood is a natural product with considerable variability. Before a softwood structural member can be used it must be either visually graded or machine graded. In this non machine grading research, considerable laboratory testing is used to develop a series of statistical relationships, so that softwood properties such as modulus of elasticity and modulus of rupture of the recovered softwood can be estimated from the softwood's specific gravity, annular rings per inch and date of construction of the building being demolished. A decision can then be taken whether the timber should be machine graded for reuse. The research describes the laboratory test arrangements and the statistical analysis used to estimate the softwood strength properties.