Browsing Research articles (Dept of Civil Engineering) by Title
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Mwewa, W.L. (University of Botswana, www.ub.bw, NaN, 1999)[more][less]
Abstract: The demand for adequate training of artisans and apprentices in the construction industry cannot be over emphasized in view of the rapid changes the industry is undergoing. Many of of these changes are continously taking place especially in the areas of utilization and maintainability of construction materials. The local vocational institutions should vigorously embark on reviewing the vocational education and training. This will result in the supply of cadres with acceptible quality of training in order to meet the challenges of the building industry. In spite of the ten years of involvement by the local vocational institutions in the training of artisans and apprentices there is still shortage of skilled manpower. The aim of the paper, therefore, is to assess the relevance of the vocational training programs and the trends of output of artisans and apprentices trained before and after the second construction boom from boom from 1986 to 1990 and 1992 to 1996. URI: http://hdl.handle.net/10311/882 Files in this item: 1
Mwewa_BJT_1999.pdf (1.091Mb) -
Abadjieva, T. (University of Botswana, NaN, 1998)[more][less]
Abstract: Investigations of the influence of various factors on the modulus of elasticity and deformability of different types of lightweight concrete are presented.The results show that the modulus are not constant and decrease with the increase of the level of applied stress. Aggregate proposity and volume fraction effects the modulus of elasticity and the modulus of deformability of concrete. Using different concrete mixes of varying strength, it was confirmed that the the modulus of elasticity and the comprehensive strength of concrete are directly proportioned. The modulus of elasticity per unit strength decreases with the age of concrete. As lightweight concrete is a heterogeneous, multiphase material, the volume fraction and modulus of elasticity of the principal constituents influence the modulus of elasticity of the composite material. URI: http://hdl.handle.net/10311/611 Files in this item: 1
Abajieva_BJT_1998.pdf (1.208Mb) -
Sahu, B.K.; Jayaram, S. (University of Botswana, NaN, 2000)[more][less]
Abstract: Alarmingly high accumulation of fly ash has led geochemical engineers into finding a solution for the use of flyash as a construction material in the recent past. As of now, although the material has been used in a limited way in the construction of roads, embarkments,dykes and by cement industries, most of it is still dumped as a waste material. There is a general opinion mongst teh Geochemical engineers that fly ash is a non-hazardous material. However, the authors felt that it may not be entirely true due to the fact that fly ash does contain quite a significant proportion of soluble salts. These salts would leak into water if fly ash comes into contact with water or if the ground water leaked through a bed of fly ash. The investigation revealed that Dissolved Oxygen of fly ash polluted tap and clean water is reduced to a level far below the permissible limit for aquatic life. The author would like to emphasise that the findings of the present investigation are being submitted to open an agenda on the issue of water pollution by the fly ash leachate, may it be ground water, water in the vicinity of the ash being used in the construction of dykes,dams, river training structures or for reclamation on sea shores. URI: http://hdl.handle.net/10311/601 Files in this item: 1
Sahu_BJT_2000.pdf (863.8Kb) -
Ssegawa, J.K.; Masambaji, C.N. (Faculty of Engineering and Technology, University of Botswana, www.ub.bw, April NaN, 2011)[more][less]
Abstract: To deliver project effectively is of paramount importance because most of the world population depend on services delivered by projects. Reports from various countries around the world, including Botswana, still indicate poor project delivery. Several causes may be advanced including ineffective project control. Devising means to alleviate the control problem is therefore, of great importance. Scholars and practitioners have suggested various techniques that monitor and keep track of projects. One of them is the earned value analysis(EVA) which touted by many as an efficient yet effective control system because of its ability to control scope, cost and time. Based on this premise, the study reported in this paper investigated possible use of EVA in building projects in Botswana. The investigation was two fold, firstly, through a questionnaire, quantity surveyors (QSs) were requested to indicate whether they have use the EVA on any building project in Botswana. Results from this survey indicated that EVA is not used at all in Botswana. In fact, majority (63%) of the QSs have not heard of the system before. The second phase of the study investigated its possible use, that is, if using EVA is more adventageous than the convectional control method (CCM). Results indicated that EVA system provide quality information that was well structured, more objective, and easily accessible to all key stakeholders in a timely and understandable manner. However, to use EVA system several challenges were also indentified which included firstly, the need to train the key players in the EVA technique.; the need to change the project regime from arms-length to a cooperative on to allow transfer and sharing of information in the design and construction phases of a project; increasing the use of IT; completing design before tendering even for other trades; and nominating sub-contractors as soon as the main contract is appointed. URI: http://hdl.handle.net/10311/875 Files in this item: 1
Ssegawa_BJT_2011.pdf (2.489Mb) -
Kanyeto, O.J. (University of Botswana, NaN, 1999)[more][less]
Abstract: Advantages of using Finite Element Method (FEM)in structural engineering practice are presented in this paper.A brief description of the method is given with the aim to illustrate the rich solid mathematical basis that makes its foundation.The paper then presents some guidelines on how to build a good model for Finite Element Analysis (FEA) purposes. The guideline emphasises the need for the analyst to have a clear understanding of the physical problem and of the behaviour of the elements he employs to carry out the analysis.A practical example presented in order to illustrate the type of analysis and results that can be obtained from a commercial FE software package. This example forms part of the research work that was carried out by the author.And finally, it is recommended that all practicing structural engineers must learn the basics of finite element method, and be equiped with some FE software packagess. Since it is the most commonly used and trusted method in the world of engineering today. In order to keep up with the rest of the world in engineering advancements, the author finds it vital to equip all engineers with the latest engineering software packages and to elevate continuing engineering education. URI: http://hdl.handle.net/10311/681 Files in this item: 1
kanyeto_BJT_1999.pdf (1.860Mb) -
Ngowi, A.B. (Taylor and Francis, http://www.pdfserve.informaworld.com/940578_73138570, NaN, 1997)[more][less]
Abstract: This paper examines the strategy of employing a hybrid combination of indigenous and modern housing construction technologies. Using a Botswana village as a case study, this paper examines four traditional house types in relation to the household income, skills, materials and aspects which could be improved by adapting industrialized methods. Using experimental houses, the case study provides the costs, benefits, potential problems and implementation considerations. The paper discusses the weaknesses and virtues of traditional construction technologies, how appropriate aspects from modern technologies can be incorporated or adapted into traditional methods and the implications for developing appropriate, affordable housing technologies URI: http://hdl.handle.net/10311/370 Files in this item: 1
Ngowi_1997_BRI.pdf (800.7Kb) -
Ngowi, A.B. (MCB University Press; Emerald Publishing Group Ltd; http://www.mcbup.com/research_registers/quality.asp, NaN, 2000)[more][less]
Abstract: Total quality management (TQM) as an integrated approach to management that represents a holistic management philosophy, rather than a series of techniques, is embedded with cultural values and assumptions that are consistent with its culture of origin. This study aims to determine the outcome of implementing TQM in a place that does not share its cultural base. A survey of 100 construction firms in Botswana found that, although the values embedded in TQM could be adopted within the organisations into which it is implemented, the cultural context of the greater society resisted some of the values. It was concluded that, for TQM to be successful in a particular cultural setting, it has to take on some of the host cultural values. URI: http://hdl.handle.net/10311/170 Files in this item: 2
license.txt (1.998Kb)ngowi1.pdf (97.37Kb) -
Ngowi, A.B. (MCB University Press, http://www.emerald-library.com, NaN, 2000)[more][less]
Abstract: Total quality management (TQM) as an integrated approach to management that represents a holistic management philosophy, rather than a series of techniques, is embedded with cultural values and assumptions that are consistent with its culture of origin. This study aims to determine the outcome of implementing TQM in a place that does not share its cultural base. A survey of 100 construction firms in Botswana found that, although the values embedded in TQM could be adopted within the organisations into which it is implemented, the cultural context of the greater society resisted some of the values. It was concluded that, for TQM to be successful in a particular cultural setting, it has to take on some of the host cultural values URI: http://hdl.handle.net/10311/350 Files in this item: 1
Ngowi_2000_JEIM.pdf (915.4Kb) -
Sahu, B.K.; Mathur, S.; Kemsley, B. (University of Botswana, NaN, 2004)[more][less]
Abstract: The national road network continues to play a fundamental and catalytic role in the promotion of social and economic development of Botswana. However, a combination of adverse climatic and geological factors, such as scarcity of conventional road building materials, near absence of a non saline surface water, and climatic extremes have dictated the need for innovative engineering approaches to highway design, construction and maintenance. In recent years application of fly ash has been considered in road construction with great interest. Fly ash is a pozzolanic material, which in the presence of water combines with lime to produce a cementetious material with excellent structural properties. Attempts have, therefore, been made at Botswana Roads Department in collaboration with University of Botswana to explore the feasibility of utilizing fly ash alone to improve the physical and strength characteristics of locally available non-standard marginal materials. The results indicate that with the addition of fly ash plasticity dereases while California Bearing Ration (CBR) increases for calcrete and other locally available marginal materials for road construction. With appropriate amount of fly ash and an adequate curing the material can be improved to meet the requirement of base and sub-base coarse. URI: http://hdl.handle.net/10311/644 Files in this item: 1
Sahu_BJT_2004.pdf (606.5Kb) -
Ngowi, A.B. (Elsevier, NaN, 1997)[more][less]
Abstract: The traditional developed earth as one of the most important construction materials by taking cognizance of the strength requirements, durability of resulting structures and the environmental concern in processing and using the material. Overthe years, however, modern earth construction has replaced the traditional methods. Unfortunately,these methods are also accompanied by high energy consumption and environmental degradation.This paper examines the methods of improving earth construction in two major villages in Botswana.Tests with different stabilizers showed that only certain proportions were effective and it was concluded that the traditional earth construction may be improved by using certain ratios of cement and lime as stabilizers. URI: http://hdl.handle.net/10311/606 Files in this item: 1
Ngowi_CBM_1997.pdf (968.2Kb) -
Malumbela, G.; Moyo, P.; Alexander, M. (Elsevier http://www.elsevier.com/locate/conbuiltmat, NaN, 2011)[more][less]
Abstract: Corrosion crack widths are often used by structural engineers in the field to predict level of steel corrosion as well as residual load-bearing capacities of corroding RC structures. This paper presents further work on this matter but with focus on corrosion crack patterns and how they affect rate of crack widening. It is based on results from a research where 17 quasi-full-scale (153 254 3000 mm) RC beams were corroded under various levels of sustained loads. The rate of widening of corrosion crack widths was found to be very much dependent on crack patterns. Deformation of cover concrete under each crack pattern was discussed. It was found that at maximum crack widths below 0.6 mm, the majority of beams exhibited nearly similar crack patterns as well as rate of widening of corrosion cracks. A mass loss of steel of 1% corresponded to a maximum crack width between 0.14 and 0.22 mm. At large crack widths (>0.6 mm), various beams exhibited very different rates of crack widening. It was shown that at crack widths above 0.6 mm, to be conservative an increase in mass loss of steel of 1% corresponded to corrosion crack widening of 0.02 mm. URI: http://hdl.handle.net/10311/676 Files in this item: 1
Malumbela1_CBM_2010.pdf (1.399Mb) -
Ssegawa, J.K.; Samman, J.; Kgatlegang, J. (University of Botswana, NaN, 2001)[more][less]
Abstract: Without cost information, project planning is difficult for clients just as pricing of tenders is difficult for construction firms. No agency or organization in Botswana has endeavoured to collect, compile and analyze construction data with a view to establish a cost/price database and a subsequent building index. This paper reports an investigation into the possibility of establishing a building index and a related cost database of building items. It is based on previous studies in Botswana, which indicated that no such information exists anywhere in the public domain and many firms have a tough time during the planning of projects and pricing of project tenders. By producing a price database of common building and a building index the study shows the possibility of establishing a fully-fledged data bank for both items. Recommendations are made on how to improve the current situation and the results of the study. URI: http://hdl.handle.net/10311/623 Files in this item: 1
Ssegawa_BJT_2001.pdf (2.314Mb) -
Muatjetjeja, B.; Chalique, C.M. (Elsevier http://www.sciencedirect.com/science?_ob=ArticleListURL&_method=list&_ArticleListID=1120288190&view=c&_acct=C000043160&_version=1&_urlVersion=0&_userid=778200&md5=2911144ac0b419d4936d24596384b313, NaN, 2009)[more][less]
Abstract: This paper aims to classify a generalized coupled Lane–Emden system and to compute the Noether operators corresponding to a Lagrangian for a generalized coupled Lane–Emden system which occurs in the modelling of several physical phenomena such as pattern formation, population evolution and chemical reactions. In addition the first integrals for the Lane–Emden system are constructed with respect to Noether operators. URI: http://hdl.handle.net/10311/416 Files in this item: 1
Muatjetjetja_CNSNS_2009.pdf (467.2Kb) -
Ketlogetswe, C. (Bentham Open http://www.bentham-open.org, January 1, 2009)[more][less]
Abstract: A number of photovoltaic pilot projects have been started in Botswana since 1990. The first photovoltaic project was Manyana PV project which started in 1992. The Japanese International Cooperation Agency (JICA) PV solar pilot project is the most recent PV solar project in Botswana, which was launched in 2003 at Kudumatse, Motlhabaneng, and Lorolwana villages. The primary objective of all these projects was to access the viability and sustainability of solar energy technology as an alternative source of energy especially for rural based communities. Depending on the findings, such projects were also intended to be replicated in other parts of the country. Despite all these efforts by the government of Botswana and donor agencies, the level of use of PV solar systems for power generation in Botswana, particularly in isolated communities, is very low. This paper, therefore, discusses the factors that impede the rapid development of photovoltaics power generation systems in the rural environment of Botswana. The study is focused on the photovoltaic power generation project which was carried out in three villages in Botswana, namely Kudumatse, Lorolwana and Motlhabaneng. URI: http://hdl.handle.net/10311/695 Files in this item: 1
Ketlogetswe_OREJ_2009.pdf (455.1Kb) -
Khalique, C.M.; Muatjetjeja, B. (Elsevier http://dx.doi.org/10.1016/j.amc.2009.01.008, NaN, 2009)[more][less]
Abstract: We carry out the Lie group classification of the generalized Lane–Emden equation xu00 þ nu0 þ xHðuÞ ¼ 0, which has many applications in mathematical physics and astrophysics. We show that the equation admits a three-dimensional equivalence Lie algebra. It is also shown that the principal Lie algebra, which in this case is trivial, has seven possible extensions. Three new cases arise for which the Lie point symmetry algebra is nontrivial. Comparison is then made of these cases with the Noether symmetry cases as well as the partial Noether operators. URI: http://hdl.handle.net/10311/415 Files in this item: 1
Khalique_AMC_2009.pdf (532.1Kb) -
Ganesan, C.T. (University of Botswana, NaN, 1999)[more][less]
Abstract: Water scarcity in arid and semi-arid countries such as Botswana; call for judicious planning and economic use. In this connection many water saving components and appliances have been devised. One such system for example is the partial flushing unit fitted to water closets, which cause the volume and flow of water in the drainage system decrease, compared with the ordinary systems. To maintain a sufficient transportation in drainage pipes connected to low flush water closets (water closets with a flow less than 6 litres per flush)it is necessary to follow a set of rules used in conventional systems. Author suggests that in countries like Botswana where availability of water is unpredictable only 4 litres per flush can be allowed for successful operations. In this paper certain rules for design and dimensioning drainage pipes for water saving systems are proposed. Besides the paper presents a complete general survey of the influence of branches and bends illustrated by means of drawings and descriptions. URI: http://hdl.handle.net/10311/618 Files in this item: 1
Ganesan_BJT_1999.pdf (1.079Mb) -
Garg, A.K.; Joubert, R.J.O.; Pellissier, R. (College of Economic and Management Sciences, University of South Africa. http://www.unisa.ac.za/default.asp?Cmd=ViewContent&ContentID=16434, NaN, 2004)[more][less]
Abstract: Most studies consider business performance to be a multidimensional construct. Four dimensions (namely, business growth, profitability, image and customer loyalty, and product service innovativeness) were hypothesised to validate a measure for business performance in the South African context. Using partial least squares, 22 responses from top executives of banks in South Africa were analysed to test the validity of the four dimensions of business performance. The results of the study suggest that the nonfinancial dimensions (namely, image and customer loyalty, and product service innovation) are not valid dimensions for measuring business performance, while the other two dimensions (namely, business growth and profitability) show a high degree of correlation. This indicates that business growth is aligned with profitability, that growth for profitability is a major concern, and that profitability still remains the key measure of business performance in the South African banking sector. Parameters such as customer loyalty and innovativeness are not regarded as important for business performance, although these could be pressing issues for banks. The paper also validates a questionnaire that can be used to measure business performance and reviews various methods for measuring business performance. URI: http://hdl.handle.net/10311/296 Files in this item: 1
Garg_SAJBR_2004.pdf (188.9Kb) -
Malumbela, G.; Alexander, M.; Moyo, P. (Elsevier http://www.elsevier.com/locate/conbuildmat, NaN, 2011)[more][less]
Abstract: Cracking of the cover concrete due to steel corrosion is considered by many researchers to indicate the end-of-service life of corrosion-affected reinforced concrete (RC) structures. Numerous models have been developed to predict the time from corrosion initiation to cracking of the cover concrete. In the previous models, concrete with corroding steel bars was assumed to behave like a thick-walled cylinder under uniform internal pressure. Recent research publications have however, shown that steel corrosion is often concentrated on the surface of the steel that faces the direction of ingress of corrosion agents. This paper presents a model that relates the level of partial surface steel corrosion with the transverse and vertical strains measured on the exterior faces of corrosion-affected RC beams. The model assumes that the remaining section of the steel after corrosion is elliptical shaped. Finally, the model is calibrated with experimental data in the literature and it is shown that assuming uniform steel corrosion underestimates the internal pressure applied by the expansive corrosion products. URI: http://hdl.handle.net/10311/682 Files in this item: 1
Malumbela2_CBM_2011.pdf (481.3Kb) -
Mark, M. (University of Botswana, http://ub.bw, NaN, 2007)[more][less]
Abstract: Botswana is facing one of its greatest development challenges at the moment. It is facing an HIV/AIDS pandemic of immense proportions. It is among the countries in the world that have been hard hit by this scourge. A lot of stakeholders including government, private companies, international donor agencies, and civil society have come up with interventions to respond to challenge of fighting this pandemic. Among the key players in this fight against HIV/AIDS are civil society organizations, commonly known as NGOs. These organizations play a crucial role of bringing HIV/AIDS services to the communities where the other players may not reach or may not be effective. The services the NGOs offer to communities are normally delivered as projects. Effective monitoring and evaluation of projects is usually one of the ingredients of good project performance and provides means of accountability, demonstrating transparency to the stakeholders and facilitates organizational learning for benefit of future projects. This study sought to determine how effectively the HIV/AIDS projects implemented by Gaborone based local NGOs are monitored and evaluated. The study investigated the monitoring and evaluation practices of the NGOs and compared them with the best practices. It also sought to identify the challenges the NGOs faced in carrying out this function. Data for the study was collected using the descriptive survey method where a questionnaire was administered to project managers and monitoring and evaluation officials of the NGOs. The results of the study show that most of the NGOs (66.7%) were implementing Behavioral Change Communication projects. The study also determined that the monitoring and evaluation practices of the local NGOs fell short of the best practices. Most of the best practices were inconsistently done and others were not done at all. Planning for monitoring and evaluation was inadequately done and inconsistently by respondents. Implementing the monitoring and evaluation process was not effectively done by the respondents. The study also identified quite a number of challenges the NGOs faced in carrying out monitoring and evaluation of the projects they faced. These challenges made it hard for the NGOs to effectively monitor and evaluate the projects they implemented. The most significant ones included; inadequate finances, lack of expertise, stringent and multi-donor reporting requirements, lack of baseline data. The study made some recommendations in order to mitigate the challenges faced by the NGOs. The study found out that, all in all the projects implemented by the local NGOs were not effectively monitored and evaluated. URI: http://hdl.handle.net/10311/991 Files in this item: 1
Mark-MEPC_2007.pdf (7.970Mb) -
Malumbela, G.; Sebusang, N. (Faculty of Engineering and Technology, University of Botswana, www.ub.bw, April NaN, 2011)[more][less]
Abstract: Concrete is the widely used construction material worldwide. Therefore, for structural safety as well as to provide economic design, it is essential to understand well, its performance. Whilst in most developed countries extensive research has been done to characterise concrete, little is known about the performance of concrete in Botswana. This paper reviews previous work carried out in other countries to assess performance of their concrete. Focus is on influence of aggregate type. It is shown from the review that there is great need to study influence of aggregate on performance of concrete in Botswana, particularly comprehensive strength. A brief description of the needed research is outlined. URI: http://hdl.handle.net/10311/889 Files in this item: 1
Malumbela_BJT_2011.pdf (934.5Kb)