Burning Characteristics of Some Selected Structural Timbers Species of Southwestern Nigeria

Abstract

Timber has been used for construction since prehistoric times. However, timber by its nature is combustible, and may be a source of building collapse during fire incidence. Hence, it warrants attention to ensure safety of the buildings. Unlike steel and concrete, the performance of timber species under fire exposure, particularly for species found in Southwestern Nigerian has not been adequately investigated. This paper determined the relationship between the physical, mechanical properties, and the burning characteristics of the selected Nigeria timber species used for structural purposes. Six species out of ten identified timber species that are used for structural purposes in building construction in Southwestern Nigeria were selected for studies in this paper. They are: Iroko (milicia excels), Teak (tectona grandis), Afara (Terminalia superb), Mansonia (mansonia altissima), Mahogany (khaya spp), and Opepe (Nauclea diderrichii). The densities of the timber species were determined at moisture contents of 9%, 12%, and 15%. Eighteen timber samples, three from each of the selected species of dimension 510mm x 150mm x 150mm, were exposed to fire for charring rate test at varying exposure time 0 - 29 minutes, 0 - 60 minutes, and 30 minutes - 60 minutes. The correlation coefficients of the predicted charring rate when compared with the actual charring rate were determined.