Civil Engineering
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Civil Engineering
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Item 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%.Item COMPARATIVE ANALYSIS OF TRAFFIC PERFORMANCE OF SMALL AND LARGE CENTRAL ISLAND ROTARIES IN MINNA, NIGERIA(SAVAP International, 2013) Abubakar, Mahmud; Ndoke, P. N.Of recent, the government of Niger state has embarked on the construction of roundabouts with small central island rotaries; this paper compares the performance of large central island rotaries with small central island rotaries. The performance of large central island rotaries compares well to the performance of small central island rotaries. Capacities of rotaries with small islands were found to be higher than capacities of large central island rotaries while the delay for large central island rotaries was found to be higher than that of small central island rotaries. However, both large and small central island rotaries were found to be operating at the same level of service. This study provides recommendations to traffic engineers and/or planners on the conditions under which both central island rotaries perform better and, thus, should be considered.Item Comparative Assessment of Macroscopic Traffic Flow Properties Estimation Methods: A Case for Moving Car Observer Method(ENGINEERING SCIENCE AND TECHNOLOGY INTERNATIONAL RESEARCH JOURNAL, 2017) Hassan Shuiabu Abdulrahman; A. A. Almusawi; Abubakar, MahmudDifferent methods of estimating macroscopic traffic properties is expected to have varying results even when they are carried out on the same road and during the same time interval. A comparative assessment was carried out between traffic data collected at a point and that collected over a short section; Moving car observer method(MCO). Student’s t-test was used to evaluate both data and it was observed that there was no significant difference between them. The MCO method correlates well with conventional data collection method and it can be used as a substitute for it, assuming conventional data collection method is trueItem ConcealedBeaminReinforcedConcreteStructures:APerformance-BasedAnalysis(NigerianJournalofScienceandEngineeringInfrastructure(NJSEI), 2024) Abubakar, Mahmud; Abdullahi, Hashim; Yabagi, Maikudi SaniThe use of hidden beams in reinforced concrete construction is seen as an effective method of reducing excessive deflection in large spans. However, despite its presumed advantages and growing usage, no mention of it in standard civil engineering literature, codes and standards. In this paper, performance-based analysis is carried out on three different cases of slab arrangement involving hidden beams using SAP2000. The process is performed under dead and live load combination and based on the design guidelines in BS8110. The result of the performance-based analysis shows a 4%, 2% and 11% decrease in deflection, stress distribution and area of bending steel reinforcement required for the case with hidden beam in comparison with the case without the hidden beam.This indicates that the presence of a hidden beam in a slab is significant. Thus, it is recommended for reducing excessive deflection in large spans, hidden beams can be introduced.Item Development of a Simplified Methodology for British DoE Concrete Mix Design Procedure using python(Nile Journal of Engineering & Applied Sciences, 2025) Aguwa, Chinedu; Abubakar, MahmudMost of the methods of concrete mix design developed over the years were geared towards manual approach. Apart from being characterized by rigorous complication in computation, manual concrete mix design is prone to errors and mistakes inherent in the calculation during interpolations and reading of charts. Thus, this research introduces an innovative integration of Python algorithms into mobile applications for concrete mix design. The tables used in this algorithm are the same as those used in the British Method, however, Charts or Figures in the British method were converted into linear and polynomial equations. Python program was written to ease the use of the algorithm and it was also configured into the backend of a mobile application for user-friendliness. The results obtained from the algorithm were compared with those obtained based on the British method manual calculations and available datasets. The percentage errors between the algorithm results and manual calculations were found to range from 0.65% to 3% across all examples. The developed algorithm is a reliable tool for automating DoE concrete mix design. It is recommended for engineers to enhance accuracy and efficiency in mix design computations.Item DEVELOPMENT OF AN ANDROID BASED MOBILE APPLICATION FOR THE DESIGN AND DETAILING OF ISOLATED PAD FOUNDATIONS ACCORDING TO EUROCODE 2(i-manager’s Journal on Mobile Applications & Technologies, 2019) Yusuf, Abdulazeez; Isiaka, I.; Abubakar, Mahmud; Aminulai, H. O.; Abdullahi, Aliyu; Alayande, T. A.In a building construction project, it is the responsibility of the structural engineer to come up with a complete design of all structural elements. When this is done manually it is tasking, time consuming, and produces errors with inconsistent results. However, the design can be done using computer software, but this also comes with some downside; it is expensive and complex to use. Thus, this research developed an android based mobile application for the design of pad foundations to Eurocode 2 to put these challenges in check when designing pad footings. The mobile application designs isolated Axially loaded-only and Axially loaded with bending pad footing to Eurocode 2 accurately, with consistent results and in a timely manner. The application was tested using typical test parameters and results are compared to the manual computations. There was no significant difference in the steel sections provided for both methods. All checks that must be satisfactory in design were all checked and found to be satisfactory.Item Development of an Android Based Mobile Application for Design and Detailing of Pad Foundations to BS8110(Epistemics in Science, Engineering and Technology, 2017) Yusuf, A.; Aminulai, H. O.; Abdullahi, A.; Abubakar, Mahmud; Alhaji, B.Many innovative computer software have been developed to perform the task of designing and detailing structural elements such as beams, columns, slabs and foundations. This design and detailing can be done using mobile devices but software developed to operate on such devices have not been fully developed. However, this research is aimed at developing an android based mobile application for the design of pad foundations to Bs8110. The mobile application developed designs isolated axially loaded-only; axially loaded with moment pad footings as well as combined pad footings. The mobile application developed was tested using three typical test parameters and results compared to the manual computations. There was no significant variation in the steel sections required and provided for the manual design and that generated by the mobile application. The steel required by manual design for the axially loaded pad footing was 835mm2/m and that generated by the application was 837.2mm2/m. That of the axially loaded with moment gave required steel section as 1019mm2/m using manual design. This android based mobile application would thus give the structural engineer the leverage to design pad footings anywhere and anytime.Item Development of Sensitivity based Model for Flexural Failure of Singly Reinforced Concrete Slabs Based on BS 8110: 1997(. Nigeria Journal of Engineering and Applied Sciences (NJEAS), 2017-03-22) Tsado, T.Y.,; Sadiku, S.,; Iorkar, A.; Kolo, D. N.This research presents mathematical models for checking the effect of variation in key designed parameters on the structural collapse of singly reinforced concrete solid slabs in buildings due to flexural failure based on British Standard (BS) 8110, 1997. The increasing complexity of construction process requires very high level of engineering and management skills to combat the structural collapses widely experienced globally. Most of the collapses were adjudged to be due to improper management arising from variations in structural key design parameters during construction, and this call for mathematical models to check the effect of variation in key design parameters on the structural collapse. The key design parameters considered in this research are; characteristic strength of reinforcement, grade of concrete, diameter and spacing of tension reinforcement, effective depth of tension reinforcement, applied moment. Sensitivity analysis was applied to study the effect of variation in the key parameters on the moment capacity. The results of sensitivity analysis were utilized in regression analysis to develop simplified equations for estimating the moment capacity of the slab. Computer programme was developed based on BS 8110, 1997 standard using Java to verify the model. Flexure safety factor was also checked based on BS 8110, 1997 requirements. Forty five numerical examples were taken to validate the model with the developed computer programme at 5% significance level using Chi-squared as an instrument for sensitivity-based model for flexural failure of singly reinforced concrete slab. The results show that the model is adequate at 5% significance level for checking flexural failure of singly reinforced concrete slab at construction stage based on BS 8110, 1997. It was recommended that the construction practitioners should consider the diverse effect of change in key deigned parameters during construction, otherwise the developed model should be strictly considered for quick safety check especially deflection safety of a solid slab during construction.Item Development of Statistical Models to predict the compressive strength of concrete produced using Quarry dust as partial replacement of fine aggregate(LAUTECH Journal of Civil and Environmental Studies, 2022-01-12) Kolo, D. N.; Enwongulu, J. O.Concrete is an assemblage of Cement, aggregates and water. The most frequently used fine aggregate for concrete production is sand sourced from river banks. The continuous use of this river sand as a result of rapid infrastructural development has resulted in its scarcity and often high cost. This paper examines the suitability of using quarry dust (QD) as partial replacement for fine aggregate in concrete production. Preliminary test (specific gravity) was conducted on the aggregates to determine their suitability for concrete production. Concrete with 5, 10, 15, 20 and 25% QD – Fine aggregate content was cast with a mix ratio of 1:2:4. The freshly prepared Quarry Dust Concrete (QDC) was cast in moulds measuring 150 x 150 x 150mm and cured using ponding method. The Compressive strength result shows that replacement of fine aggregate with QD leads to a general increase in compressive strength of concrete. Statistical package for the Social Sciences (SPSS) version 21 was utilised to develop the linear regression models for the 7 and 28 days compressive strength of the QDC. The developed models were found to be sufficient in predicting the 7 and 28 days compressive strengths with R2 values of 98.9% and 95.2 % respectively.Item Durability Characteristics of Lateritic Subgrade Treated with Iron Ore Tailings and Lime Exposed to Moisture Fluctuations(. Nigeria Journal of Engineering and Applied Sciences (NJEAS), 2018-02-11) Mohammed, A. M.; Amadi, A. A.; Aguwa, J. I.; Kolo, D. N.This research evaluated the durability of lateritic subgrade treated with Iron Ore Tailings (IOT) and lime exposed to moisture variations. Representative sample of the subgrade was treated with 0, 5, 10, 15, and 20% IOT and optimal lime percent (6.2%) determined through Eades and Grim pH test. Preliminary tests such as particles size distribution, Atterberg limits and compaction were conducted to characterize the mixtures while Unconfined Compressive Strength (UCS) and CBR-swell tests were carried out to access durability of the soil mixtures. Addition of lime to the soil increased the liquid limit to 45% from 36% obtained in natural soil. Similarly, the plastic limit of the lime-treated sample increased from 16 to 26% with reduced plasticity index. While the natural soil exhibited CBR of 3 and 75% for soaked and unsoaked specimens respectively, the value increased and peaked at 11 and 118% with addition of lime and 15% IOT. Durability of the soil improved with addition of IOT and lime. 15% IOT and lime treated soil recorded the best results with UCS of 240 kN/m2 and 200% Relative Volumetric Stability (RVS), which is a measure of strength loss of a soil. Similarly, swell value of 0% was recorded when the lime-IOT samples were subjected to CBR-Swell test. This shows that the lime-IOT treated samples are less vulnerable to moisture condition normally prevalent in the pavement subgrades.Item 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.Item Empirical Relationship between Compressive, Flexural and Splitting Tensile Strengths of Concrete Containing Kuta Gravel as Coarse Aggregate(Journal of Engineering Research and Reports, 2025-02-02) Abubakar, J.; Abdullahi, M.; Aguwa, J. I.; Abbas, B. A.; Kolo, D. N.Flexural and tensile strengths of concrete are of great importance in structural engineering. Understanding the flexural strength of concrete helps designers prevent and control development of cracks in concrete elements, ensuring durability. In addition to serviceability, shear, bond failure and flexural capacity in concrete members are directly linked to the tensile strength of the concrete. When compared to flexural and tensile strengths, determination of the compressive strength of concrete is easier to carry out in the field. It is therefore, customary to determine the compressive strength and correlate it to other strength properties. In this study, empirical relationships have been developed to relate the compressive strength to the flexural and splitting tensile strengths of concrete using Kuta river gravel as coarse aggregate. Using varying total aggregate to cement, coarse aggregate to total aggregate and water to cement ratios, 20 mixes were generated using Central Composite Design (CCD) in Minitab 21. The compressive, flexural and splitting tensile strengths of concrete samples from these mixes were determined at 28 days of age. From the strength data obtained, regression equations were developed that relate the strength properties with the aid of regression analysis tool in Microsoft Excel. The empirical models developed to predict the flexural and splitting tensile strengths of concrete from the compressive strength recorded R2 values of 1 for both models, P-values of 5.23 × 10−29 and 4.47 × 10−30, and standard errors of 0.21 and 0.06 respectively. Furthermore, residuals from the values of predicted strength properties show that there is very slight deviation between the experimental and predicted values. It was concluded that the empirical equations developed are significant, have high predictive capabilities and can be used in predicting the flexural and splitting tensile strengths of concrete.Item Numerical Investigation of Reinforced Concrete Beam Containing Iron Ore Tailings as Partial Replacement of Sand(Conference: 4 th International Conference on Innovations and Challenges in Engineering and Technology for Sustainable DevelopmentAt: Arba Minch University, Ethiopia, 2023) Abubakar, Mahmud; Haruna, M. I.; Abdulrahman, H. S.; Abbas, B. A.The production of industrial and agricultural residual by-products can generate significant environmental impact. In response, researchers have begun incorporating supplementary materials made from agro-industrial wastes to create more sustainable concrete. However, testing the performance of these waste-based concrete mixtures can be time-consuming and expensive. To address this issue, this study utilized three dimensional non-linear Finite Element simulation using the ABAQUS/CAE software to predict the behavior of a reinforced concrete beam that incorporated 20% IOT as partial sand replacement. The simulation successfully predicted the damage behavior of the 20% IOT concrete, indicating the potential of this modeling approach to accurately predict the performance of waste-based concrete mixtures in various designs.Item Optimization Of The Adsorption Process In Landfill Barrier Using Response Surface Methodology (Rsm)(IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE), 2024-04-17) Asogwa E.O; Adie D. B; Ibrahim F.B; Amadi. A.A; Saidu M; Adesiji A.R; Mangey J.AResponse Surface Methodology was used to examine the percentage of heavy metal removal from a sanitary landfill site utilising a lateritic soil-geopolymer composite. By Using the model, the lateritic soil geopolymer composite's adsorption potential was enhanced. The applicability of the employed model to predict the adsorption state is supported and confirmed by the good agreement between the observed and anticipated values of the removal efficiency. The applied models showed that all three of the components examined had an impact on the removal of heavy metals from sanitary landfill liners, but that the effects of dosage and contact time were more pronounced and had a substantial impact on the removal % of heavy metals. With dosage and contact time proving to be the most relevant of the three independent variables, the ANOVA findings show that the model parameters are significant. After refining the replies, the following settings proved ideal: dosage of 10g, contact time of 48 hours, and temperature of 50 °C. These yielded percentage removals of lead, zinc, and copper of 97.88%, 94.36%, and 99.48%, sequentially. Keywords: Heavy Metals, Geopolymer, Landfill, Barrier, Optimization, Lateritic-soil, Response Surface Methodology (RSM)Item PARTIAL REPLACEMENT OF FINE AGGREGATE WITH WASTE GLASS IN CONCRETE MADE FROM BIDA NATURAL AGGREGATE(3rd International Engineering Conference (IEC 2019) Federal University of Technology, Minna, Nigeria, 2019) Alhaji, B.; Kolo, D. N.; Abubakar, Mahmud; Yusuf, A.; Abdullahi, A.; Mohammed, S.This study reports the experimental investigation on the suitability of waste glass as partial replacement for fine aggregate in concrete made using Bida natural aggregates (BNA). Glass is widely used in our daily lives through manufactured products such as sheet glass, bottles, glassware, and vacuum tubing. It is an ideal material for recycling. The increasing awareness of glass recycling speeds up inspections on the use of waste glass with different forms in various fields. Mix ratio of 1:2:4 batched by weight with water – cement ratio of 0.55 was used. The percentage replacement varied from 0% to 40% at 5% intervals. Slump test was conducted to assess the workability of the fresh concrete. The compressive strengths and densities of cured concrete cubes of sizes 150mm x 150mm x 150mm were evaluated at 7, 21 and 28days. A total of 81 concrete cubes were cast and tested. It was observed that an increase in the percentage replacement of fine aggregate with waste glass reduces workability, density and compressive strength. The compressive strength and density vary with days of curing. The findings of this study indicated that the optimum replacement percentage of waste glass with conventional fine aggregate was 20%. However waste glass can effectively be used as fine aggregate replacement (up to 40%) without substantial change in concrete strength.Item Partial Replacement of Fine Aggregate with waste Glass in Concrete made from Bida Natural Aggregate(. Proceedings of the 3rd International Engineering Conference, Federal University of Technology Minna, Nigeria, 2019-02-05) Alhaji, B.; Kolo, D. N.; Abubakar M.; Yusuf A.; Abdullahi, A.; Shehu, M.This study reports the experimental investigation on the suitability of waste glass as partial replacement for fine aggregate in concrete made using Bida natural aggregates (BNA). Glass is widely used in our daily lives through manufactured products such as sheet glass, bottles, glassware, and vacuum tubing. It is an ideal material for recycling. The increasing awareness of glass recycling speeds up inspections on the use of waste glass with different forms in various fields. Mix ratio of 1:2:4 batched by weight with water cement ratio of 0.55 was used. The percentage replacement varied from 0% to 40% at 5% intervals. Slump test was conducted to assess the workability of the fresh concrete. The compressive strengths and densities of cured concrete cubes of sizes 150mm x 150mm x 150mm were evaluated at 7, 21 and 28days. A total of 81 concrete cubes were cast and tested. It was observed that an increase in the percentage replacement of fine aggregate with waste glass reduces workability, density and compressive strength. The compressive strength and density vary with days of curing. The findings of this study indicated that the optimum replacement percentage of waste glass with conventional fine aggregate was 20%. However waste glass can effectively be used as fine aggregate replacement (up to 40%) without substantial change in concrete strength.Item POTENTIAL OF CALCIUM CARBIDE RESIDUE MODIFIED SANDCRETE BLOCKS IN ENHANCING THERMAL AND ENERGY EFFICIENCY FOR SUSTAINABLE BUILDING DESIGN(2nd Faculty of Engineering and Technology Conference (FETiCON 2024), Jun. 2 - 6, 2024, University of Ilorin, Nigeria, 2024) Ibrahim, M; Abubakar, Mahmud; Abdullahi, Aliyu; Abbas, B. A.Sustainability has increasingly become a prominent topic in the field of construction, and as such, it is necessary to explore means of reducing the overdependence on the use of cement in construction works. This study investigated the effects of calcium carbide residue (CCR) as a partial substitute for cement in sandcrete blocks. Due to the high pH value of calcium carbide residue, its disposal in landfills increases the alkalinity of the environment. From raw material extraction through final product disposal, the construction industry is integrally involved in every stage of the lifecycle of greenhouse gas emissions. In this study, cement was partially substituted using CCR at 0% and 12% by weight replacement. The sandcrete blocks were of 450 mm × 225 mm × 225 mm dimensions and made from a Cement-CRR mix ratio of 1:6 and water-cement ratio of 0.6. Preliminary tests such as consistency, setting times, soundness, and specific gravity tests were carried out on cement and cement + 12% CCR. The thermal properties, which include thermal conductivity (k), heat transfer coefficient (U), specific heat capacity (Cp) and diffusivity (α) of the sandcrete blocks were determined. The thermal tests were carried out after the 28th day of curing. The result showed that CCR increased the water demand by the sandcrete blocks, hence reducing its workability. The sandcrete block samples made with 12% CCR replacement showed improved compressive strength. The k for 0% and 12% replacement was 0.5497 W/mK and 0.3978 W/mK, respectively, while the U was 54.974 W/m2K and 39.784 W/m2K, respectively for the 0% and 12% replacement. On the other hand, the Cp for 0% and 12% was 0.0003364 J/kg°C and 0.0001598 J/kg°C, respectively, while the diffusivity was 636.54m2/s and 1113.94m2/s for 0% and 12% replacement, respectively. As such, we can infer that 12% CCR replacement of cement gives more energy-efficient and sustainable sandcrete blocks.Item Probability based design of concrete mixes with cow-bone ash admixed cement(Leonardo Journal of Sciences, 2017) Abubakar, Mahmud; Mohammed Abdullahi; James Isiwu AguwaA probability-based procedure for design of concrete mixes with cow-cone ash admixed cement has been developed considering the strength as a random variable. However, the compressive strength of concrete in turn, depends on the properties of its constituent materials: cement, fine aggregate, coarse aggregate and cow-bone ash. The compressive strength data generated experimentally has been analysed using normal-probability distribution functions based on 95% confidence interval. The proposed probability based design was compared to the method of trial mixture. It was observed that for reliability index (β) of 1.3, the proposed probability methodology uses 10.2% less cement content than the method of trial mixture; thus, indicating that the method is conservative. It was also observed that, for concrete grade 25, the proposed methodology gives higher compressive strength at both 7 and 28 days. Hence, the probability-based design procedure was found appropriate and is therefore recommended for the design of concrete mixes with cow-bone ash admixed cement.Item PROBABILITY-BASED CALIBRATION OF LOAD DURATION MODIFICATION FACTORS FOR THE NIGERIAN GROWN TIMBER(NIGERIA JOURNAL OF ENGINEERING AND APPLIED SCIENCES (NJEAS), 2023) Aguwa. J. I.; Sadiku, S.; Afolayan, J. O.; Abdullahi, A.; Abubakar, Mahmud; 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.Item 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.