Browsing by Author "Abubakar, M."

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A Comparative Analysis of Grillage method and Beam line analysis of a reinforced concrete waffle bridge deck
(Nigeria Journal of Engineering and Applied Sciences (NJEAS), 2022-01-12) 8. Adamu, H. N.; Abbass, B. A.; Abubakar, M.; Yusuf, A.; Kolo, D. N.; Shehu, M.
The analysis of reinforced concrete waffle bridge deck using chanchaga bridge as a case study was carried out with the aid of computer program written in MATLAB. The bridge deck which is a beam bridge was idealized to be a waffle slab. A mathematical model of the bridge was developed using the method of grillages because very complex shapes of problem domain with prescribed conditions can be handled easily using the method. The bridge deck was modelled as interconnection of grid elements. The analysis was carried out using direct stiffness matrix method. The nodal displacements and the resulting static internal forces; shear forces, bending moments and twisting moments of each grid element were determined using the matrix. The results obtained using the method of grillages were then compared with beam line analysis and the former method gave a 10% decrease in forces which will result in the reduction of overall design and materials by 10%.
A Comparative Analysis of Grillage Method and Beam line Analysis of a Reinforced Concrete Waffle Brifge Deck
(Nigeria Journal of Engineering and Applied Sciences (NJEAS), 2022-01-23) Adamu, H. N.; Abbas, B. A.; Abubakar, M.; Yusuf, A.; Kolo, D. N.; Shehu, M.
The analysis of reinforced concrete waffle bridge deck using Chanchaga bridge as a case study was carried out with the aid of computer program written in MATLAB. The bridge deck which is a beam bridge was idealized to be a waffle slab. A mathematical model of the bridge was developed using the method of grillages because very complex shapes of problem domain with prescribed conditions can be handled easily using the method. The bridge deck was modelled as interconnection of grid elements. The analysis was carried out using direct stiffness matrix method. The nodal displacements and the resulting static internal forces; shear forces, bending moments and twisting moments of each grid element were determined using the matrix. The results obtained using the method of grillages were then compared with beam line analysis and the former method gave a 10% decrease in forces which will result in the reduction of overall design and materials by 10%.
Effect of Partial Replacement of Fine Aggregate with Sawdust in Light Weight Concrete Production Using Bida Natural Stone as Coarse Aggregate
(Proceedings of the 3rd International Engineering Conference, Federal University of Technology Minna, Nigeria, 2019) Alhaji, B.; Abubakar, M.; Yusuf, A.; Oritola, S. F.; Mohammed, S.; Kolo D. N.
This study investigated the effect of sawdust as partial replacement for Fine Aggregate in light weight concrete production. Sawdust was used to replace Fine Aggregate from 0% to 40% in steps of 5%. 150 x 150 x 150mm concrete cubes were cast for each replacement level, the concrete was cured and the compressive strengths were determined at 7, 21 and 28days curing period respectively. Increase in percentage of sawdust in concrete stant reduction in the compressive strength values with a corresponding reduction in weight. From the result obtained, 5% replacement of Fine Aggregate with sawdust gave a maximum compressive strength 13.11 N/mm2. It was however concluded that the optimum replacement level of 5% can be used as plain concrete for blinding works.
Effectiveness of Locust Bean Epicarp Extract on Re-vibrated Concrete Using Pebbles from Bida Environs as Coarse Aggregate
(Proceedings of the Sustainable Education and Development Research Conference, University of Environment and Sustainable Development, Somanya, Ghana, 2023-01-02) Abbas, B. A.; Mohammed, T. A.; Yusuf, A.; Kolo, D. N.; Abubakar, M.; Abdullahi, A.
Probability-Based Calibration of Load Duration Modification Factors for the Nigerian Grown Timber
(2023-01-02) Aguwa, J. I.; Sadiku, S.; Afolayan, J. O.; Aliyu, A.; Abubakar, M.; Kolo, D. N.
All along, load duration modification factors used in Nigeria for design of timber structures were based on BS 5268 of 2002 and this is not a good engineering practice since the strength of timber depends so much on the soil as well as on the environment. There is the need to localize the modification factors based on our environment since Nigerian grown timber is generally used for all timber structures designed and built in Nigeria. Probability-based calibration of load duration modification factors for the Nigerian grown timber was successfully carried out. The results showed significant difference between the calibrated factors and those from BS 5268 of 2002. The calibrated modification factors are; 1.25 for long-term, 1.35 for medium-term, 1.70 for short term, and 2.0 for very short-term duration. This paper recommends the use of these calibrated load duration factors based on Nigerian grown environment.
Production of Pavement Blocks Using Low Density Polyethylene Product Waste
(Proceedings of the 4th International Conference (SETIC), School of Environmental Technology, Federal University of Technology, Minna, Nigeria, 2023-01-02) Aboje, A. A.; Abbas, B. A.; Kolo, D. N.; Abubakar, M.; Abdulsalam A. M.
Waste sachet water packs cause considerable land pollution in Nigeria. In this research, pavement block was produced using low density polyethylene products waste (sachet water packs) as an alternative binder. The production was achieved by first converting the sachet water packs into pellets and blending it with sandstone in a mass ratio of 8:2 (A), 7:3 (B) and 6:4 (C) sandstone to pellets respectively. The compressive strength, %water absorption and curing time tests were carried out on the pavement block to determine it suitability and safety for low-traffic use. The compressive strength for polymer concrete samples A, B and C were 13.65N/mm2 , 16.99N/mm2 and 20.34N/mm2 respectively. After carrying out the %water absorption test on the polymer concrete A, B and C the following result was obtained: 8.33%, 5.47% and 4.03% respectively. It should be noted that the polymer concrete samples and the control samples which (are cement concrete based) are for light-traffic use (pedestrian, plazas, shopping complexes ramps, car parks, office drive ways, rural roads with low traffic, and residential road).
Reliability Studies on Reinforced Concrete Column Subjected to Axial Load with Natural Stone as Coarse Aggregate
(Nnamdi Azikiwe University Journal of Civil Engineering (NAUJCVE), 2024-01-02) Kolo, D. N.; Aguwa, J. I.; Abubakar, M.
This paper presents the reliability assessment of a reinforced concrete column subjected to Axial loading. Locally available natural aggregate (NA) was used in concrete production, the results of preliminary tests revealed the aggregate was adequate for concrete production. A typical column cross section of 230 × 240 × 3000mm was adopted and probabilistically assessed. First Order Reliability Method (FORM) was employed to estimate the implied probabilities of failures. The results of the sensitivity analysis showed that the reinforced concrete column is structurally safe at length, breadth and depth of 3200, 240 and 230 mm with Probability of Failures of 1.14 ×10-3, 8.45 × 10-4 and 8.45 × 10-4 respectively.
Structural Reliability Studies of Reinforced Concrete Beam subjected to Shearing forces with Natural Stone as Coarse Aggregate
(USEP: Journal of Research Information in Civil Engineering, 2019-02-12) Kolo, D. N.,; Aguwa, J. I.,; Tsado, T. Y.,; Abdullahi, M.,; Yakubu, D. M.,; Abubakar, M.
This paper presents experimental and structural reliability studies performed on Bida natural stones (BNS) used as coarse aggregate in concrete production. Construction activities based on these naturally occurring materials are major steps towards industrialisation and economic integration of developing countries like Nigeria. This explains the huge interest over the years in utilising such materials as substitute or partial replacement for concrete constituents. The method adopted to appraise the aim and objectives of the study was laboratory experimentation. A total of 80 concrete cubes of 150 mm × 150mm × 150 mm were cast and used for this study. First order reliability method (FORM) was employed to ascertain the level of safety of the beam. Sensitivity analysis was further conducted by varying the span, effective depth and area of shear reinforcement of the beam in shear. The result revealed that the reinforced concrete beam utilising Bida natural stones is structurally safe at a span of 3000 mm and 3250 mm for unwashed and washed Bida natural stones respectively with probabilities of failure of 1.07 × 10-3 and 1.14 × 10-3. Both unwashed and washed Bida natural stones were structurally safe at effective depth of 439 mm with probabilities of failure of 5.87 × 10-3 and 1.31 × 10-3in shear.