Structural suitability of 10-year old Pinus caribaea timber with a forest fire history in farm buildings

Abstract

Forest fires in Pine and Eucalyptus plantations are common in Uganda especially in the dry periods. In an event of fire gutting a nearly mature plantation, tree farmers usually try to reduce losses by extracting and lumbering the residual trees for use in agricultural buildings. However, there is no empirical data to guide material selection based on strength and structural integrity of the timbers from burnt plantations. Therefore, this study investigated the effect of fires on selected physical and strength properties of timber extracted from a 10-year old stand of Pinus caribaea that had been burnt. Test specimens were prepared and tested for MOE, MOR and compression parallel to the grain using a Testometric AX M500 – 25KN Universal Testing Machine in accordance with the British stand ASTM D 198 (2003) and BS 373: (1957). For comparison purposes structural size specimens from same age stands that were unaffected by fire were concurrently tested. The data were statistically analyzed using One-way ANOVA test. The results indicated that burnt trees had significantly lower density, MOE and MOR than the unburnt trees. It is recommended that timber extracted from burnt trees should not be used for high strength structural purposes but could rather be used in low strength construction works such as shuttering and ceiling works.