Civil Engineering

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Civil Engineering

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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.
Probability based design of concrete mixes with cow-bone ash admixed cement
(Leonardo Journal of Sciences, 2017) Abubakar, Mahmud; Mohammed Abdullahi; James Isiwu Aguwa
A 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.
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, Mahmud
Different 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 true
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.
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.
Hygrothermal Effects of Partial Replacement of Coarse Aggregates with Palm Kernel Shell in Concrete Production
(Nigeria Journal of Engineering and Applied Sciences, 2017-08-12) Abdullahi A.; Abubakar M.; Aminulai H. O; YUSUF, Abdulazeez; Alhaji B.
Hygrothermal effects of partial replacement of coarse aggregates with Palm Kernel Shell (PKS) in concrete production were assessed. Preliminary tests were conducted on PKS to determine its suitability for use as aggregate in concrete production. Workability and Density of the fresh concrete were also determined. Cylinders of 100mm diameter by 50mm height were used to cast the concrete; these were cured for 28 days and tested for water absorption and sorptivity at different replacement levels of coarse aggregates with PKS. The sorptivity of concrete was found to increase with increase in PKS content, however, between 5-25% PKS content, lower sorptivity values than control were recorded. Water absorption of concrete also increased with increase in PKS content, PKS contents from 5-20% gave water absorptions below the control and at 25% replacement, a slightly higher value as compared to the control was recorded. From the results obtained, concrete with 5% PKS content was found to possess the best water absorption as well as sorptivity values. Such concrete adequately fits for use in areas where concrete water absorption and sorptivity are required to be kept at a very minimal level; such as in the construction of drainages and dams.
Development of an Android Based Mobile Application for Design and Detailing of Pad Foundations to BS8110
(Epistemics in Science, Engineering and Technology, 2017-12-10) YUSUF, Abdulazeez; H. O. Aminulai; A. Abdullahi; M. Abubakar; B. Alhaji
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
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.
ASSESSMENT OF THE PROPERTIES OF HIGH STRENGTH CONCRETE MADE USING QUARRY DUST AS FINE AGGREGATE
(1st International Civil Engineering Conference (ICEC 2018), 2018-09-22) Mohammed T.A.; YUSUF, Abdulazeez; Abdullahi A.
The study was carried out to assess the properties of High-strength concrete made using Quarry dust as Fine aggregate. Preliminary tests were carried out on the aggregates to determine their suitability for use in High- strength concrete. The aggregates were well graded and other properties met the requirements of aggregates to be used for High-strength concrete. Superplasticizer and Rice husk were used as chemical and mineral additives to improve the workability and other properties of the concrete. Based on the properties of the aggregates, a mix ratio of 0.23:0.51:0.044:1.05:0.7:0.2, representing cement: fine aggregate: coarse aggregate: superplasticizer: water: rice husk was used. Concrete cubes of 100x100x100 mm were cast, cured and the 28-day compressive strength determined. An average 28-day compressive strength of 63 N/mm2 was obtained. This can be categorized as class I high strength concrete and is applicable in the construction of high rise buildings. The Study therefore concludes that quarry dust can be used as total replacement for fine river sand in high strength concrete production.
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.
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.
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.
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.
Flexural Strength of Revibrated Concrete Using Iron Ore Tailings (IOT) as Partial Replacement for River Sand
(Journal of Research Information in Civil Engineering,, 2020-10-10) YUSUF, Abdulazeez; A. I. Emmanuel
River sand is one of the major concrete constituents. Sand mining from rivers results in several environmental problems which leads to destruction of river banks among others. The use of IOT as a substitute for river sand is capable of addressing this problem. The effect of partial replacement of river sand with IOT on the flexural strength of revibrated concrete was studied in this paper. Sieve analysis, bulk density specific gravity and water absorption tests were conducted on the IOT, river sand and crushed granite to ascertain their suitability for use in concrete. A mix ratio of 1:2.1:2.7 and water-cement ratio of 0.5 was used to prepare concrete mixes with 0%, 10%, 20%, 30%, 40%, 50%, and 100% IOT as sand replacement. A total of 63 prisms of size 100 x 100 x 500 mm were cast and revibrated 30s for 3 minutes within 1 hour to provide samples to be tested for flexural strength at 7, 14 and 28 days curing age. Results revealed that the workability of concrete decreased with increase in percentage of IOT. Highest flexural strength was noted with concrete containing 100% IOT at all curing ages. Flexural strength model was proposed as a function of % IOT at 28 days curing age. It was recommended that IOT can be used as either partial or total replacement for river sand in concrete.
Statistical Model for Predicting Slump and Strength of Concrete Containing Date Seeds
(Covenant Journal of Engineering Technology (CJET), 2021) Yusuf, A; Jamal, J. O.; Abubakar, Mahmud; Aminulai, H. O.
Incorporating agro-based waste in concrete can reduce environmental pollution and lead to preserving the ecosystem. In order to reduce trial and error in achieving desired slump and compressive strength of concrete containing Date Seed (DS), this paper examines the slump and compressive strength of concrete using date seeds as a partial replacement for crushed granite. Preliminary tests were conducted on the aggregates to ascertain their suitability for concrete production. Concrete with DS-crushed granite ratios of 0:100, 5:95, 10:90, 15:85, and 20:80 were prepared using a mix ratio of 1:2:4 and a water-cement ratio of 0.5. Slump loss was used to estimate the workability of the fresh concrete. The freshly prepared concrete was cast in 150 x 150 x 150 mm and the compressive strength was determined after curing by full immersion in water for 7, 14, 21 and 28 days. Results showed that the slump of concrete increased with an increase in the content of date seed. The compressive strength was inversely proportional to the date seed content with a DS crushed granite ratio of 20:80 recording the lowest compressive strength (20N/mm2). Linear regression models for slump and compressive strength were developed and found to be sufficient in explaining the experimental data based on a Mean Square Error (MSE) of 0.37 and 0.029 and R2 of 88% and 99% obtained for slump and compressive strength respectively. The study has concluded that DS can be used as a partial replacement for crushed granite in concrete and a linear model is sufficient in predicting the slump and strength of concrete containing date seeds.
Modelling Slump of Concrete Containing Natural Coarse Aggregate from Bida Environs Using Artificial Neural Network
(Journal of Soft Computing in Civil Engineering, 2021-05-02) YUSUF, Abdulazeez; M. Abdullahi; S. Sadiku; J.I. Aguwa; B. Alhaji; T.A. Folorunso
Consumption of crushed granite as coarse aggregate in concrete has led to devastating environmental and ecological consequences. In order to preserve local and urban ecology therefore, substitute aggregate such as naturally occurring stone with the propensity of reducing this problem was studied. Furthermore, artificial Neural Network (ANN) models have become the preferred modeling approach due to their accuracy. Thus, in this paper, MATLAB software was used to develop ANN models for predicting slump of concrete made using Bida Natural Gravel (BNG). Four model architectures (5:5:1; 5:10:1; 5:15:1 and 5:20:1) were tried using a back-propagation algorithm with a tansig activation function. The performance of the developed models was examined using Mean Square Error (MSE), Correlation Coefficient (R) and Nash-Sutcliffe Efficiency (NSE). Results showed that 5:20:1 model architecture with MSE of 8.33e-27, R value of 98% and NSE of 0.96 was the best model. The chosen 5:20:1 ANN model also out performed Multiple Linear Regression (MLR) model which recorded MSE of 0.83, R value of 88.68% and NSE of 0.87. The study concluded that the higher the neuron in hidden layer of ANN slump model for concrete containing BNG, the better the model.
Reliability studies on reinforced concrete beam subjected to bending forces with natural stone as coarse aggregate
(Springer, 2021-10-10) Daniel Ndakuta Kolo; James Isiwu Aguwa; Theophilus Yisa Tsado; Mohammed Abdullahi; YUSUF, Abdulazeez; Sikiru Folahan Oritola
This paper presents the results of structural reliability analysis of a structural element (beam) in building using First-order reliability method (FORM) to ascertain the level of safety. The natural stone (NS) which is the by-product of Precambrian deposits of the Bida trough was used as coarse aggregate: unwashed and washed aggregates were used. A total of 80 concrete cubes of 150 mm × 150 mm × 150 mm were cast and used for this study, sensitivity analysis was conducted by varying the span, depth, effective depth, area of shear reinforcement and dead load of the beam in bending. The result of the sensitiv ity analysis revealed that the beam utilising unwashed and washed NS are both structurally safe at a span of 3000 mm with probabilities of failure of 9.20 × 10–5 and 2.06 × 10–8 and both safe at a depth of 600 mm with probabilities of failure of 4.19 × 10–4 and 2.602 × 10–4, respectively, in bending.
Models to predict the fresh and hardened properties of palm kernel shell concrete.
(Malaysian journal of civil engineering, 2022) Kolo, Daniel Ndakuta; Tsado, T.Y; Abbas, B.A; Adamu, H. N
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 exploitation of available granite conventionally used as coarse aggregate in concrete production coupled with rapid infrastructural development has resulted in its scarcity and often high cost. The suitability of utilising Palm Kernel Shell (PKS) as partial replacement for coarse aggregate in concrete production was examined in this paper. Preliminary tests were conducted on all aggregates to determine their suitability for concrete production. Concrete with 5, 10, 15, 20 and 25% PKS-coarse aggregate content was cast with a mix ratio of 1:2:4. The freshly prepared Palm Kernel Shell Concrete (PKSC) was cast in moulds measuring 150 x 150 x 150mm and cured using ponding method. The Compressive strength result shows that an increase in the PKS content results in a decrease in compressive strength of concrete. Linear regression models for the slump and compressive strength of the PKSC were developed and found to be sufficient in predicting the compressive strengths with R2 values of 96% and 92 % respectively.
Structural Assessment of a Lattice Tower in Federal Capital Territory, Abuja
(Nigeria Journal of Engineering and Applied Sciences (NJEAS), 2022-01-02) Auta, S. M.; Okunyomi, O. O.; Kolo, D. N.
Since the licensing of GSM operators in Nigeria from 2001, there was an astronomical increase in construction and maintenance towers. In a bid to reduce maintenance cost, tower sharing was adopted by some telecommunication providers. The Nigerian Communications Commission guidelines for installation of masts and towers stipulates that all lattice towers should be checked for their structural health status every five years. This requirement has promoted this research work. The objective of the study includes selection of a lattice with weakest parameters, determine the tower’s structural stability and its utilization percentage. A 45m tower with 3-legs erected over 8 years and shared by three telecommunication operators in the Federal Capital Territory (FCT) was selected. Audit was conducted on the tower and its foundation. There were no warped member and no visible crack on the tower foundation. The average compressive strength of the stub columns determined using the digital Schmidt hammer were 25.1, 25.9 and 25.9 N/mm2 for legs A, B and C. From the structural analysis using the EPA model, the tower utilization percentage was found to be at 59.4% after optimization. The STAAD pro. V8i analysis showed that the utilization ratio of the tower members is ≤ 1. Furthermore, design properties for the tower members are less than the properties of the actual tower members used and there was no failed member identified after the structural analysis. In conclusion, the lattice tower can be said to be stable and fit for continuous use.
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%.