Civil Engineering
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Civil Engineering
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Item 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.Item 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. EmmanuelRiver 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.Item 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 OritolaThis 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.Item 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. FolorunsoConsumption 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.Item 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. AlhajiMany 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 anytimeItem 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.