Browsing by Author "Mushule, Nurdin K."
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Item Accuracy of Road Management Data Collection at Various Information Quality Levels(Department of Civil Engineering, JKUAT, 2006) Mushule, Nurdin K.A complete pavement management system contains a number of different decision-support systems which operate together with an information system. Types of decision-support systems include planning, programming, preparation and operation. Planning systems are used for strategic planning to develop long term plans for the road network as a whole whilst programming systems are used to develop medium term plans. On the other hand, preparation and operation systems are employed for project preparation and management of maintenance operations, respectively. The most detailed data is required for the operation system whilst the planning system utilises the least detailed data. This paper presents the results of a research project which was carried out in Tanzania in order to establish the loss of data accuracy as the data collection moves from very detailed level (IQLI) to a higher Information Quality Level (IQLIV). In this study two types of defects, which have been found to be predominant in Tanzania, namely cracking and potholing, were investigated. The study found that there is a significant loss in data accuracy (for potholing and cracking assessment) as the level of data detail progresses from IQLI to higher level IQLs. However, the study demonstrated that, for the network level analysis, the impact of the loss in data accuracy on the resulting first year work programme and budget estimates is not as significant.Item Approach to Implementing Sustainable Road Management Systems in Developing Countries: A Case Study of Tanzania(2001) Mushule, Nurdin K.; Kerali, H. R.Several pavement management systems (PMSs) have been implemented in developing countries without taking into consideration the needs, requirements, and capacity of the implementing agencies. These systems have tended to specify requirements aimed at high-tech solutions that are often not sustainable in developing countries. As a result, many such systems have largely been marginalized. This paper describes a research project conducted to develop a framework and specifications for a sustainable network level PMS for Tanzania. The research concluded that, for the sustainability of a PMS, simple but technically sound methods should be used during the development and implementation phase.Item Behaviour of Recycled Asphalt Pavements at Low Temperatures(NRC Research Press, 1991) Sargious, M.; Mushule, Nurdin K.This paper summarizes the results of a study conducted to evaluate the behaviour of recycled asphalt pavements with respect to low-temperature cracking. For this purpose, a recycled mix consisting of 45.2% reclaimed materials and 54.8% virgin materials as well as a virgin control mix were used in the research program. In the design of both mixes, their initial properties were kept as close as possible to each other to allow for a proper comparison between recycled and virgin asphalt pavements. Using mix properties that were determined experimentally in the laboratory, thermal stresses resulted from drop in temperature and the expected cracking temperatures were determined for both mixes. An experimental analysis based on laboratory tests that consider the pavement properties only as well as a more complete theoretical analysis based on a finite element computer program known as FETAB were included in this study. The program incorporates subgrade parameters, as well as pavement properties and thickness. Using these variables as inputs to the program, the expected performance of recycled and virgin asphalt pavements of various thicknesses and resting on different types of subgrade, with respect to low-temperature cracking, was studied. The results of the study indicated that recycled asphalt pavements would perform better than virgin asphalt pavements of similar initial properties. Key words: asphalt, finite element, low-temperature cracking, reclaimed, recycled, thermal stresses.Item Evaluation of Recycled Asphalt Pavements in Cold Climates(Civil Engineering, University of Calgary, 1990) Mushule, Nurdin K.Item Implementation of New Highway Management Tools in Developing Countries: A Case Study of Tanzania(Transportation Research Board of the National Academies, 2001) Mushule, Nurdin K.; Kerali, H.In many developing countries like Tanzania, one of the major management problems is the lack of decision-making tools for preparing road maintenance programs. This deficiency results in poor resource allocation and poor utilization of existing assets. This paper summarizes the results of a pilot study on implementing sustainable highway management tools in Tanzania. It was recognized at the beginning of the study that data acquisition is one of the single most expensive items in the implementation of a pavement management system. Consequently a sustainable data acquisition scheme, appropriate to developing countries, was designed and tested. The research showed that using these methods together with appropriate management tools results in better management information. It is envisaged that the methods developed will help Tanzania to determine appropriate resource requirements as well as cost-effective pavement maintenance and rehabilitation programs.Item An Investigation on the Behaviour of Concrete with Waste Tyre Rubber Fibres as a Partial Replacement of Coarse Aggregate(Trans Tech Publications, 2012) Kumaran, Senthil G.; Lakshmipathy, M.; Mushule, Nurdin K.Concrete is an excellent structural material and considered as essential for the modern civilization and human society. Now, use of waste tyres in concrete has become technically feasible and the concrete is being considered as light weight concrete. The composites were formed with 0%, 5%, 10%, 15%, 20% and 25% of fibers replaced by coarse aggregate weight. The fibers were of different lengths (L) such as 25mm, 50mm and 75mm had holes of diameters (D) 4mm, 5mm and 6mm. The holes functioned as anchors in the cement matrix so that the tyre fibres shall not be separated while placing in the mould. The 3rd, 7th and 28th day’s compression strength and crack patterns were observed on cubes. Split tensile strength on 14th and 28th day were tested on cylindrical specimens. Test results have shown that the increase in rubber content decreases the compressive strength, but, increases the strain energy while conducting the split tensile tests. The composite with fiber specimen L50-D5 and L50-D6 with 10% replacement of coarse aggregate had shown better results than other specimens. However, further studies are needed to reveal the hidden properties of tyre fiber modified concrete.Item Sustainability of Road Roughness Measurements in Countries with Low Income Economies(Botswana Polytechnic, 2005) Mushule, Nurdin K.A research project was carried out to establish a sustainable procedure for road roughness measurement applicable in developing countries. Out of many devices in use today, a vehicle mounted bump integrator (VMBI) was selected for the reasons that: a) the equipment is available in most developing countries and it has been in use for sometime; b) the rate and accuracy of measurement is adequate; and c) it is easy to use. However, it was found that it is very difficult, time consuming and hence not sustainable to use a bump integrator for very rough unpaved roads. Consequently, a procedure which relates travel tim e (at comfortable travel speed) and road surface roughness was established. The results show that, if this procedure is properly followed, the roughness obtained are in a very close agreement with those obtained from using the bump integrator.