Civil Engineering
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Civil Engineering
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Item Analysis of Safety Performance in Nigerian Construction Industry(Nigeria Journal of Engineering and Applied Sciences (NJEAS), 2018-02-22) Kolo, D. N.,; Tsado, T. Y.,; Abdullahi, M.,; Yakubu, D.M.,; Aguwa, J. I.The quest for the provision of adequate housing for all has translated to the increase in activities of Building construction industry in Nigeria. This growth is accompanied however with cases of poor safety performancewhich at times leads to structural failure. This study investigates and analyses safety performance in Nigerian construction industry. Investigatory survey research method (work study) was adopted to appraise the aim and objectives of the study through field and questionnaire approach. Questionnaire survey consisting of a five point Likert scale was conducted to solicit information from the respondents, and a total of 120 questionnaires were issued to construction professionals and workers on the sites visited. 92 questionnaires representing 76.67% response rate were retrieved and analysed using Statistical Package for Social Sciences (SPSS) version 21. Communalities test, Principal Component Analysis along with ANOVA were utilised for data analysis. A total of thirty-two (32) factors influencing safety performance were identified from literature, subsequently principal component analysis was utilised to reduce the list to nine (9) significant principal factors. The top nine principal factors influencing safety performance determined from the research are: Relationship between Supervisors and Employees on site, Geographical Location (Environmental Factors: Natural and Working Environment), Working Procedure, Ear defenders not worn (while working under noisy equipment), Talk by Management on Safety, Tidy Site, Safety Communication, Operatives job experience and Ladders used without being tied secured. These factors were further incorporated into a regression model. The adjusted coefficient of determination of the model was 0.98; this shows that the model has the capability of explaining 98% of variability in the data under consideration. This implies that the model is adequate in evaluating safety performance. It is therefore recommended that key industry professionals and stakeholders should channel available resources to the determined nine (9) principal safety performance factors.Item Effect of Aggregate Washing on Compressive Strength of Concrete produced Using Bida Natural Stone(Proceedings of the 2nd International Civil Engineering Conference, Department of Civil Engineering, Federal University of Technology Minna, Nigeria., 2020-02-01) Kolo, D. N.; Aguwa, J. I.; Tsado, T. Y.; Alhaji, B.; Joseph, O. F.Concrete is the most widely used construction material in the world, second to water as the most utilised substance on earth. Coarse aggregate is an essential component in concrete production; it has effect on the workability and mechanical properties of concrete. Bida Natural Stone (BNS) which is the by-product of Precambrian deposits of Bida trough was used as coarse aggregate, utilising unwashed and washed aggregates. A total of 80 concrete cubes of 150 × 150 × 150 mm were cast and used for this study, compressive strength tests were conducted after 28 days curing. The result of physical properties test conducted proved that BNS is suitable for concrete production. The result of compressive strength tests conducted shows that concrete produced using washed aggregate results in an increase in average compressive strength of about 11.46 % when compared to that produced using unwashed aggregate. Hence, construction professionals and workers utilising this aggregate (BNS) in the Bida basin are encouraged to practice aggregate washing before concrete works.Item Reliability studies on reinforced concrete beam subjected to bending forces with natural stone as coarse aggregate(Asian Journal of Civil Engineering, 2020-01-12) Kolo, D. N.; Aguwa, J. I.; Tsado, T. Y.; Abdullahi, M.; Yusuf, A.; Oritola, S. F.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 sensitivity 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 Reliability Studies on Reinforced Concrete Column Subjected to Axial Load with Natural Stone as Coarse Aggregate(Nnamdi Azikiwe University Journal of Civil Engineering (NAUJCVE), 2024-01-02) Kolo, D. N.; Aguwa, J. I.; Abubakar, M.This paper presents the reliability assessment of a reinforced concrete column subjected to Axial loading. Locally available natural aggregate (NA) was used in concrete production, the results of preliminary tests revealed the aggregate was adequate for concrete production. A typical column cross section of 230 × 240 × 3000mm was adopted and probabilistically assessed. First Order Reliability Method (FORM) was employed to estimate the implied probabilities of failures. The results of the sensitivity analysis showed that the reinforced concrete column is structurally safe at length, breadth and depth of 3200, 240 and 230 mm with Probability of Failures of 1.14 ×10-3, 8.45 × 10-4 and 8.45 × 10-4 respectively.