VIEWS: 11 PAGES: 7 CATEGORY: Earth Sciences POSTED ON: 5/22/2010
Currently, because field-ready approaches are not available, individual wood members used in light-frame construction are typically replaced when fire reduces the total dimension of a member by approximately 1/4 inch or more in depth. Accordingly, the objective of this study is to provide a more quantitative approach for assessing serviceability of such members charred near this threshold but otherwise expected to remain in service. After quantifying the results, equations were developed using a statistically based analysis. These equations are believed to adequately represent the mean residual flexural properties for the materials and grades listed above when exposed to similar field conditions and fire scenarios. It was found that subjecting the wood specimens to charring near the above-mentioned threshold resulted in a decrease in the moment of inertia of 30%-40% and a reduction of specific gravity of the residual sample on the order of 5%-10%. Depending on the material, reductions in the apparent modulus of elasticity and modulus of rupture ranged from 13%-25% and 32%-37%, respectively.
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"Post-fire assessments, methodology, and equations for directly determining wood's residual flexural properties"Please download to view full document