Browsing by Author "JIMOH, A.A."
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Item CHARACTERISATION AND GRADING OF TWO SELECTED TIMBER SPECIES GROWN IN KWARA STATE NIGERIA(FACULTY OF ENGINEERING , UNIVERSITY OF NIGERIA, NSUKKA, 2017) JIMOH, A.A.; AINA, S.T.This study investigates the physical and mechanical properties of two timber species for structural use. Three logs of each specie were obtained at different areas of Kwara State, of Nigeria which is located north in the periphery of the south-western rain forest area,sliced into 2” by 12” size before seasoning naturally and their structural/strength properties were determined at a moisture content of 18%. These logs were cut into test samples for the determination of their properties. A total of 351 samples (45 samples for each test) free from visible defects was used for each specie. Basic physical properties of the samples like moisture content, specific gravity and density was determined. Tensile strength, modulus of rupture, modulus of elasticity, compression, shear and hardness were the mechanical tests carried out according to BS 373 (1957), CP112 (1971), NCP2 (1973), EC5 (1995) and BS 5268 (2002) specifications on Universal Testing Machine (UTM). Results were analysed statistically using Analysis of Variance (ANOVA). A. Indica was graded into strength class D40 while X. Aethiopica was grade into strength class D70.Item Evaluation of Compressive Strength Characteristics of Structural-sized Apa (Afzelia bipindensis) and Opon (Lannea schimperi) Timber species columns found in Nigeria(Journal of Applied Sciences & Environmental Management, 2017) JIMOH, A.A.; RAHMON, R.O.; ; JOSEPH, S.G.The work centers on the compressive strength characteristics of Nigerian Apa (Afzelia bipindensis) and Opon (Lannea schimperi) timber species columns of nominal lengths 200, 400, 600 and 800mm and a nominal width and thickness of 50mm by 50mm. The data revealed that, Apa and Opon have an average density of 652.74 and 472.60kg/m3 respectively. The mean moisture content (MC) of both species were less than the fibre saturation point (FSP) recommended value of 25-30% and the average strength at yield of Apa and Opon are 35.65 and 14.00N/mm2. The derived continuous equations for design of Apa column and Opon column are = . . and = . . respectively. The results of the reliability analysis show that Apa and Opon timber species have reliability index of 0.64 and 0.65 respectively for a service life of 50 years, assuming other serviceability conditions are met. This design procedure is distinct and more effective than the usual procedure of classifying compression members as short, intermediate and long using their slenderness ratios. The paper therefore recommends the adoption of these equations for the design of compression members from these timber species in Nigeria