Civil Engineering
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Civil Engineering
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Item Assessment of the Compressive Strength of Concrete Produced with Fine Aggregate from Different Locations in Minna(3rd International Engineering Conference (IEC 2019) Federal University of Technology, Minna, Nigeria, 2019) Aminulai, H. O.; Abdullahi, A.; Abubakar, Mahmud; Abdulrahman, H. S.; Alhaji, B.; Joseph, O. F; Aliyu, S. YThe construction industry in Nigeria has been witnessing serious collapse of buildings resulting from the qualities of materials used in their construction. This continuous collapse necessitates the need to investigate some of the materials used in the production of the building components in order to ascertain their appropriateness. This research thus investigates the compressive strength of concrete produced using fine aggregate from different locations in Minna. Fine aggregates were obtained from Chanchaga, Maikunkele, Bosso, Lapai Gwari and Garatu areas of Minna and subjected to series of tests namely: sieve analysis, Specific gravity, bulk density, moisture content, and water absorption. Concrete samples were produced using the mix ratio 1:2:4 and the water/cement ratio of 0.6. These samples were subjected to both the slump test and compressive strength test. For each of the fine aggregates, nine cubes of concrete (150mm x 150mm x 150mm) were cast, cured and tested at 7, 14 and 28 days. The results obtained for the mean compressive strength of the concrete produced shows that they all have mean strength greater than 20N/mm2 with fine aggregate from Chanchage having the highest mean of 25.17N/mm2 at 28days of curing. Thus all the fine aggregates could be used in the production of structural lightweight concrete but for structures that require higher strength, the fine aggregate from Chanchaga is recommendedItem 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 Analysis of Statically Determinate Trusses using Exact Method (Joint Resolution Method) and Matrix Stiffness Method(USEP: Journal of Research Information in Civil Engineering, 2017) Abdullahi, A.; Yusuf, I. T.; Abubakar, Mahmud; Aminulai, H. O.; Yusuf, A.; Alhaji, B.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.Item Modelling the Slump, Compressive Strength and Density of Concrete Containing Coconut Shell as Partial Replacement for Crushed Granite(USEP: Journal of Research Information in Civil Engineering, 2017) Abdullahi, M.; Aminulai, H. O.; Alhaji, B.; Abubakar, MahmudIn this research, crushed coconut shell was used to partially replace crushed granite as coarse aggregate in the production of concrete. Tests were conducted on the physical properties of crushed coconut shell and crushed granite. Thirty one random mixes were generated using Mini Tab 14 statistical software package. A total of 108 cubes were cast and cured for 28 days and then crushed to determine their compressive strength. The results were used to develop empirical models for the slump, compressive strength and density of the concrete. The concrete developed in this work has slump ranging from 0 – 135 mm, compressive strength ranging from 8.94 N/mm2 – 27.11 N/mm2 and density ranging from 1757.04 kg/m3 to 2198.52 kg/m3 respectively. This implies that concrete made using coconut shell as partial replacement for crushed granite can be used for structural application such as in the construction of reinforced concrete slabs, beams, columns and foundations. Polynomial model was developed with the capability of explaining the under-laying relationship of 93.8%, 83.6% and 72.3% for slump, compressive strength and density respectively.Item Hygrothermal Effects of Partial Replacement of Coarse Aggregates with Palm Kernel Shell in Concrete Production(Nigerian Journal of Engineering and Applied Sciences (NJEAS), 2017) Abdullahi, A; Abubakar, Mahmud; Aminulai, H. O.; Yusuf, A.; 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.