Civil Engineering

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Civil Engineering

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    Comparison of Drying Shrinkage Models of IOT Concrete
    (Conference: 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria, 2017) Oritola, S. F.; Abd Latif, Saleh; Abdul Rahman, Mohd.Sam; Abubakar, Mahmud; Alhaji, B.
    Problems associated with drying shrinkage of concrete is still a major source of concern in the construction industry. Due to the hygral nature of concrete, particularly the instability of the volume as a result of drying shrinkage, concrete will crack at any stage during its service life. The depletion of the environment due to huge consumption of sand for construction is another major problem. Iron ore tailings (IOT), an industrial waste, generated during the production of iron ore is utilized in concrete to lessen the environmental problems. The iron ore tailings was sourced from a local iron ore producing mine and the material was used as partial replacement for sand to produce normal weight concrete. The drying shrinkage of this concrete was compared with that of the control normal weight concrete. The ultimate drying shrinkage of the concrete samples were further studied, using three prediction models. The inclusion of iron ore tailings as fine aggregate in concrete contributed to reduction of the drying shrinkage recorded at 28, 56 and 90 days as well as the ultimate drying shrinkage. The drying shrinkage of concrete and the predicted ultimate drying shrinkage recorded by the B3 and GL2000 models agreed more closely, as compared with the recorded values obtained using ACI209R model.
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    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.; 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 to40%) without substantial change in concrete strength.
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    Effect Of Water Cement Ratio On The Compressive Strength Of Revibrated Concrete
    (Environmental Technology and Science Journal, 2015) Auta, S. M.; Abubakar, Mahmud; Yusuf, A.
    Effect of water cement-ratio on compressive strength of re-vibrated concrete is presented. The mix proportion of 1:2:4 aggregates were considered to cast 39 cubes each as laboratory specimen with 0.65, 0.70 and 0.75 water-cement ratios. Each of these categories were revibrated at time lag intervals of 10minutes for 120 minutes period of revibration process and cured for 7, 21 and 28 days. When tested for their respective compressive strength, the result obtained shows that there is a gradual increase in compressive strength of the concrete specimen with increase in time and in water-cement ratio. The maximum compressive strength at 120th minute for ages of 28 days are 25.42, 26.67 and 40.44N/mm2 for concrete with water-cement ratio of 0.65, 0.70 and 0.75 respectively. The maximum attained compressive strength for 28 days curing is 40.44N/mm2 (for 0.75w/c) appears to be higher than 25.42N/mm2 (for 0.65 w/c). Water-cement ratio has adversely enhanced the compressive strength of concrete when re-vibrated.
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    Design of A Composite Traffic Control System at Kpakungu Roundabout Minna, Niger State
    (Nigeria Journal of Engineering and Applied Sciences (NJEAS), 2016) Kolo, S.S.; Adeleke, O. O.; Ayeni, S. J.; Akinmade, T.; Abubakar, Mahmud; Yusuf, A.
    A composite traffic control method is proposed to control traffic and ease congestion especially during peak periods at Kpakungu roundabout in Minna, Niger state. Reconnaissance survey of the roundabout was carried out to note predominant directions of traffic flow from each approach to the roundabout; manual counting of traffic for five working days was done between 7:00 am to 12 noon and 3:00 - 7:00 pm daily. The result of the survey shows that congestion occurs at the roundabout between 7:45 - 9:30 am and between 5:00-6:30 pm every day. Results also show that the peak hourly traffic flow rate occurs between 8:00 and 9:00 am, and 5:00 to 6:00 pm daily. The result of the traffic count was then forecasted for 2-years using data on annual vehicle registration in Minna for 2011 to 2015 obtained from the Niger State Board of Internal Revenue Service. The Webster method of signal timing was used to design traffic signals that will optimally allocate right of way time to conflicting traffic streams. A 5-phase signalization of 90- and 97-seconds cycle lengths were proposed for morning and evening peak periods, respectively.
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    Design of A Composite Traffic Control System at Kpakungu Roundabout Minna, Niger State.
    (Nigeria Journal of Engineering and Applied Sciences (NJEAS), 2016-08-10) Kolo S.S; Adeleke O. O; Ayeni S. J; Akinmade T; Abubakar M.; YUSUF, Abdulazeez
    A composite traffic control method is proposed to control traffic and ease congestion especially during peak periods at Kpakungu roundabout in Minna, Niger state. Reconnaissance survey of the roundabout was carried out to note predominant directions of traffic flow from each approach to the roundabout; manual counting of traffic for five working days was done between 7:00 am to 12 noon and 3:00 – 7:00 pm daily. The result of the survey shows that congestion occurs at the roundabout between 7:45 - 9:30 am and between 5:00 - 6:30 pm every day. Results also show that the peak hourly traffic flow rate occurs between 8:00 and 9:00 am, and 5:00 to 6:00 pm daily. The result of the traffic count was then forecasted for 2-years using data on annual vehicle registration in Minna for 2011 to 2015 obtained from the Niger State Board of Internal Revenue Service. The Webster method of signal timing was used to design traffic signals that will optimally allocate right of way time to conflicting traffic streams. A 5–phase signalization of 90 and 97 seconds cycle lengths were proposed for morning and evening peak periods, respectively.
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    Analysis of Statically Determinate Trusses using Exact Method (Joint Resolution Method) and Matrix Stiffness Method
    (USEP: Journal of Research Information in Civil Engineering, 2017-10-10) A. Abdullah; I. T. Yusuf; M. Abubakar; H. O. Aminulai; YUSUF, Abdulazeez; B. Alhaji
    Matrix Stiffness Method (MSM) as a tool for static analysis of structures is premised on the principle of Finite Element Method (FEM), which in itself is a numerical/approximate method capable of giving only approximate results. However, Joint Resolution Method (JRM) is one of the most popular classical/exact methods of static analysis capable of giving exact results. This paper presents an analysis of a statically determinate 2-D truss using Exact/Joint Resolution Method (JRM) and Matric Stiffness Method (MSM) to ascertain the validity of the latter against the former. In the JRM, the support reactions and internal member forces were obtained from considerations of the equilibrium conditions of the entire truss and isolated joints respectively. On the other hand, a computer program was written in MATLAB 7.8.0 (R2009a) based on the principles of MSM for ease of computation and increased accuracy to solve for member forces and reactions of the same truss. The element properties were obtained and employed to calculate the element stiffness matrices, these were then assembled into the global stiffness matrix, from which the unknown displacements, member forces and support reactions were calculated. The results obtained from using both JRM and MSM were found to be exactly the same or very close, with percentage errors ranging between 0% and 3%. Hence MSM results as compared to JRM have 97% accuracy and above, and can therefore be relied upon.
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    DEVELOPMENT OF AN ANDROID BASED MOBILE APPLICATION FOR THE DESIGN AND DETAILING OF ISOLATED PAD FOUNDATIONS ACCORDING TO EUROCODE 2
    (i-manager’s Journal o Mobile Applications & Technologies, 2019-01-10) YUSUF, Abdulazeez; H. O. AMINULAI; A. ISIAKA; A. ABDULLAHI; M. ABUBAKAR; T. A. ALAYANDE
    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.
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    Computer-aided analysis of reinforced concrete waffle bridge deck using the method of grillages
    (International Civil Engineering Conference (2018) (ICEC2018)., 2018) Adamu, H. N.; Sadiku, S.; Bala Alhaji
    This paper aims to analyse a reinforced concrete waffle bridge deck using method of grillages where the topping and ribs are analysed as a monolithic unit in contrast to the conventional methods where the slab and beams are analyzed differently. In addition, the grillage approach accounts for the torsion that is usually lost in the conventional approach. The slab loading is in line with the HA loading of the BS 5400 part 2 for lightly loaded (accommodation) bridges. One of the strength of this approach is that it is amenable to computer application which has been demonstrated by using a code written in Matrix Laboratory (MATLAB) software and therefore easy for field use by practitioners. For the purpose of rendering this approach amenable to computer application, a program was used to determine the displacements, bending moments and torsional moments in the bridge deck. It is observed that the values of bending moments obtained from grillage analysis are lower than the moments from conventional beam-slab analysis carried out manually. Bending moments and other responses generated by conventional beam-slab approaches are usually exaggerated thereby reducing the anticipated benefits of waffle slab.
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    Effect of Partial Replacement of Cement with Cow Dung Ash Using Bida Natural Coarse Aggregate
    (School of Environmental Technology, Federal University of Technology, Minna, 0022-10-05) Abbas, B. A.; YUSUF, Abdulazeez; Kolo, D. N; Aboje, A. A.; Mahmud, M.B.; Ndaiji, A. U.
    The research investigates the effect of partial replacement of cement with cow dung ash (CDA) in concrete production using Bida natural coarse aggregate. Water to cement ratio and mix ratio of 0.6 and 1:2:4 was adopted respectively. The aggregates used were characterized and the cow dung was calcined at a temperature between 400-500oC. Concrete was produced using CDA as cement replacement at 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35% and 40%. Slump of the freshly produced concrete was determined and the compressive strength of the hardened concrete was determined at 7, 21 and 28 days of curing. The sum of SiO2, Al2O3 and Fe2O3 in CDA exceeds the 70% minimum specified by ASTMC 618-12. The slump of the fresh concrete ranges from 0 – 40 mm while the compressive strength at 28 days curing duration ranges from 12.59N/mm2 19.29N/mm2 and density was 2323.95kg/m3– 2554.59kg/m3 respectively. The test results revealed that the compressive strength decrease with increase in CDA content and increase with curing age. The strength results indicate that there was no much significant difference between the control specimen with 0% CDA and that containing 5% CDA. This implies that concrete made using CDA as partial replacement for cement can be used for structural applications such as in the construction of reinforced concrete slabs, beams, columns and foundations. The study concluded that CDA has pozzolanic properties and can be used to replace up to 10% cement in concrete produced using Bida natural coarse aggregate.
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    PARTIAL REPLACEMENT OF FINE AGGREGATE WITH WASTE GLASS IN CONCRETE MADE FROM BIDA NATURAL AGGREGATE
    (3rd International Engineering Conference (IEC 2019), 2019-09-22) Alhaji B.; Kolo, D. N.; Abubakar M.; YUSUF, Abdulazeez; 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.