Browsing by Author "Adeyemi, F.O."
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Item Characterisation and Grading of Four Selected Timber Species Grown in Nigeria in Accordance with Bs 5268(Nigeria Journal of Technology (NIJOTECH), 2021-07-04) Wilson, U.N.; Mohammad, Y.N.; Mohammed, I.S.; Adeyemi, F.O.This study presents a development of strength classes for Vitex doniana, Diospyros mespliformis, Parkia biglobosa and Isoberlinia doka, northern Nigeria timber species in accordance with BS 5268-2 (2002) and NCP 2 (1973). The specimens for the experimental measurements were obtained from timber-sheds in Zaria, Kaduna - Northern part of Nigeria. The laboratory experiments were conducted to determine the physical and mechanical properties of the selected timber species. The specimens were prepared in accordance with BS 373 for small clear specimens for the determination of physical and mechanical properties. Flexural strength properties were determined using three point bending test. Adjustment was made on the mechanical properties at moisture content of 12% and 18% in conformity with BS 5268-2 (2002) and NCP2 (1973) respectively. The laboratory data were analyzed using data analysis tool pack in Microsoft excel 2019 to generate the mean, coefficients of variation and theoretical distribution models which form the uncertainty models. Basic and grade stresses were also computed using experimental failure stresses. The selected timber species were then classified using the grade bending stress, density and mean modulus of elasticity obtained. Vitex doniana, Diospyros mespliformis, Parkia biglobosa and Isoberlinia doka were assigned to strength classes D30, D40, C40 and D30 in accordance with BS 5268-2 (2002) respectively. Similarly, in accordance with the NCP 2 (1973), these species belong to N4, N3, N4 and N3 respectively. The results obtained show that Vitex doniana, Diospyros mespliformis and Isoberlinia doka are hardwoods whereas, only Parkia biglobosa is a softwood specie.Item Impact Energy Assessment on Rubber-Tyre Concrete using different Methods on Two- Weibull Parameters(International Journal of Advances in Engineering and Management (IJAEM), 2021-12-12) Ibrahim, A.O.; Adeyemi, F.O.; Umar, Y. K.; Bello, M.; Usman, M.In this study, an attempt was made to investigate the effect of fire on impact resistance of tyre-rubber concrete (TRC), subjected to drop weight test in accordance with the procedure suggested by ACI committee 544. For this, three samples were prepared from each series of mix containing tyre\ fibres of 10 mm width and length in various proportions viz., 0%, 2.5%, 5.0% and 7.5%, with a water cement ratio of 0.55. The results obtained were statistically investigated using Weibull Distribution. The Weibull parameters were determined by three estimation approaches; EPM (Energy Pattern Method), Probability Density Function (PDF) and Method of Moment (MOM). Analysis suggested that the three methods are more effective in estimating the weibull parameters. Though there are less differences. Therefore, designers can choose impact strength design value based on the required reliability.