Variations of Density and Compressive Strength Before and After Charring of Some Selected Construction Timber Species of Southwestern Nigeria
FUOYE Journal of Engineering and Technology
This study aimed to evaluate the percentage variations of density and compressive strength of some selected timber species mostly used for constructional purposes in Southwestern Nigeria after undergoing fire exposure. The species are: Terminalia superba (Afara), Milicia excelsa (Iroko), Nauclea diderrichii (Opepe), Khaya ivorensis (Mahogany), Mansonia altissima (Mansonia), Tectona grandis (Teak).The densities and the compressive strengths of the species were determined at Moisture Contents
... isture Contents (MC) of 9.0, 12.0, and 15.0%. Nine specimen per species, were exposed to fire at various temperature ranges.The results of analysis by variance revealed that at 9% MC, Mahogany had the lowest density value of 439±10.58Kg/m³. At 12 and 15% MC, Afara had the lowest density values of 444±4.18Kg/m³ and 469±7.07Kg/m³ respectively. At 9, 12 and 15% MC, Opepe had the highest density values of 630±28.85Kg/m³, 686±22.64Kg/m³ and 752±17.22Kg/m³ respectively. Afara of 9, 12 and 15% MC had the lowest compressive strength parallel to the grain values of 9.59±1.08N/mm2, 9.59±1.08N/mm2 and 8.13±1.01N/mm2 respectively, while Mahogany had the highest compressive strength parallel to the grain values of 16.57±0.50N/mm2, 15.17±0.49N/mm2 and 12.12±0.42N/mm2 at the three MC levels. Post fire exposure revealed that Afara had the highest percentage change in density and compression in parallel values, while both Iroko and Mahogany exhibited the lowest percentage change in density and compression in parallel values. This study indicated that Mahogany and Iroko species which had lowest post fire change in density and compression in parallel values are useful and recommended to ensure the safety in case of fire outbreaks.