A project report submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Engineering. Johannesburg 1998. / Various studies have been done to show that labour-based construction can meet the high standards normally required in the construction of roads. The organisational requirements that were needed to ensure the efficient use of labour have also been dealt with in various studies. Tile need for alleviation of poverty, unemployment and the negative social impact thereof by increasing the labour input in construction is understood by all concerned. A further step is however necessary before the idea of increasing the . labour component in any kind of roadwork can be taken seriously. Engineers need to move forward from the policy and organisational issues associated with labour intensive construction and start to provide designers with sound and innovative engineering solutions to overcome the hurdles experienced on the ground. The study looks at the process of foam bitumen stabilisation of soils and gravels with a view of utilising this innovative method for labour intensive construction. The material after having been stabilised can be placed in a stockpile. Actual durations that the material can safely remain in stockpile have been determined in this study to be in excess of six months for recycled asphalt and in excess of four months for the foam stabilised sand. Foam stabilised gravel was also studied and showed that after a year in stockpile the material failed probably due to a weakening of the bitumen and aggregate bond. Covering the stockpiled material did not show any significant difference to that of a similar uncovered stockpile. The position within the stockpile also did not have much effect on the engineering properties of the stoc piled material. The fact that the foam stabilised material can be worked on when cold and that it can be stockpiled for several months implies that the material is labour friendly and can be used in labour intensive construction of road base course layers or wearing course layers. / AC2017

published_or_final_version / Civil Engineering / Master / Master of Philosophy

The environmental aspect of sustainability is currently high on many agendas due at least in part to the issue of climate change, manifesting in the monitoring of C02 emissions from all activities within all industrial sectors, with construction projects being no exception. The concept of Whole Life Carbon (WLC) involves understanding the carbon impact of an infrastructure project from its beginning, through its serviceable life, to the end of its life. The WLC concept can be applied to future infrastructure projects to assist in decision making, to ensure the correct project is taken forward in terms of minimising carbon emissions across the life time of the infrastructure. The life cycle of a highway project comprises the planning, design, construction, operation, use and decommissioning phases. For a new 23km motorway project in the UK, when considering the construction and use phases, the C02 emissions from vehicles using the road comprised 91% over a 40 year period. With the majority of C02 resulting from the use phase, any measures taken to minimise the impacts of this could potentially significantly reduce the C02 over the lifetime of a highway. It is during the planning stage that decisions can be made to reduce the WLC; by forecasting the impact of different design options at the different future phases of the life cycle. This thesis considers the effect of highway alignment, which is a decision taken early in a project's life cycle. The gradient of a highway can have a significant impact on the fuel consumption (and hence C02 emissions) of the vehicles operating on it. To design the alignment around an optimum earthworks phase in terms of time, cost and carbon may result in a construction phase with a lower impact, yet the long term effect of the subsequent gradients on vehicle fuel consumption may yield a significantly higher level of C02 emissions than the amount saved during the efficient construction operation. Conversely, an intensive earthworks operation may result in a C02 intensive construction phase yet result in long term benefits throughout the life cycle, as the fuel consumed by the vehicles operating on the highway is reduced. To understand the effect of the vertical alignment through the life cycle, the C02 in both the construction and use phases has been calculated. A methodology to calculate the C02 from the earthworks operations has been developed. The instantaneous emission model, PHEM, has been used to calculate the C02 from the vehicles using a highway. Different vehicle types have been assessed over hypothetical terrains, with the application of varying fleet mixes and vehicle speeds enabling an understanding of the effect of alignment on typical vehicle flows. These alignments have been modified, requiring more C02 intensive earthworks operations, to understand the potential benefits the new alignment can bring to the use phase, and the overall life cycle. The methodology developed has been applied to an actual case study that had six very different horizontal and vertical alignments. A second real and current project was used to gain an understanding of the C02 impacts of choosing an embankment over a viaduct structure.

Accessibility of the forest is a basic requirement for a commercially managed forest. Logging in British Columbia often is carried out in remote areas where log transportation is primarily by truck hauling on forest roads. Forest road construction and particularly earth moving are significant elements in the total cost of forest products. Proper choice of road design elements will determine the optimum economy of any forest road. The derivation of road design elements is shown in detail as an introduction to the earth allocation problem. Minimization of costs of main forest access roads is studied in this thesis and alternate methods of mass allocation are presented. A semi-graphical method of mass allocation (mass diagram) is compared with a method employing the electronic computer and the tools of operations research (linear programming). The theory of linear programming (LP) is shown as the optimization technique used for minimizing the earth moving costs. The LP assumptions and limitations are discussed. The two methods were tested on the forest main haul road C in the University of British Columbia Research Forest. Calculations of volume distribution and the required intermediate calculations are carried out with an electronic computer for comparison with traditional methods. The mass diagram method might be used for a long time due to its simplicity, whilst LP provides a more precise solution. The costs of earthmoving and planning are $84.00 or 0.6% of the total earthwork and planning costs less by using LP rather than the mass diagram in the example calculated. The use of dynamic programming (DP) to determine the optimum road lay-out is suggested as a topic for further research, a preliminary step for optimization in mass allocation. / Forestry, Faculty of / Graduate

No description available.

No description available.

The purpose of this project, accomplished as part of NCHRP Project 4-8 of the same title, was to discover and describe possible areas of needed research which if successfully pursued would assist the highway materials engineer in development of procedures for the evaluation of aggregate properties and, in turn, would lead to the more efficient use of our aggregate supplies. A comprehensive series of statements of research problems was developed and categorized into four general areas of study which are: (I) Portland Cement Concrete (II) Bituminous Concrete and Related Materials (III) Base Course and Shoulder Materials (IV) General (involving at least two of the first three areas) The formulation of the research problem statements was based upon information obtained from an extensive literature survey, a Workshop Conference involving 51 “authorities” in various fields of aggregates, and a follow-up interview program. A total of 52 statements was developed with a total estimated cost of $5,499,500. A priority rating system was also developed and applied to each project. If only the top priority project in each of the four study areas were funded, the cost is estimated to be $670,000. The relative priority ratings indicate the significance of the problem statements. A solution to the priority one project of Group I, for example, relating to D-line cracking in concrete, would cure a persistent problem which engineers thought was solved. The major conclusion from this study is that the framework for selective aggregate research has now been developed and program funding is the next matter for concern. / M.S.

For organizations such as state departments of transportation, other public agencies, or private companies, adopting a new approach to procure services for delivery of construction projects requires significant organizational changes; modifications to both their work processes and existing organizational structures may be needed. These adjustments, encompassing many different aspects of the organization's interests, must occur for the change initiative to be successfully put into practice. In this research, the adoption of integrated project delivery methods within the transportation project sector is investigated to better understand the dynamics of this change. In the context of this study, an Owner's project delivery strategy is defined as the set of project delivery methods that are adopted for delivering capital projects. This dissertation presents findings from a study of Public Owner organizations that have implemented the designbuild method for delivering highway projects. Using as a case study the new $1.3 billion SH-130 tolled expressway project in Central Texas, the author analyzed project documentation and conducted many interviews with individuals affiliated with owner, legal, engineering consultants, and contractors. Findings suggest that project representatives institutionalize practices and routines connected to the new approach by adapting to new challenges, rather than "overwriting" previously existing practices. Similarly, the institutionalization of innovative approaches to project delivery happens concurrently with a deinstitutionalization of the previous approaches. Building upon these findings, a conceptual framework is presented for helping Owner organizations implement change in their project delivery strategy. The proposed conceptual framework is based upon both existing published literature and interviews with managers involved in implementing a strategic change in project delivery strategy. This framework was further refined by making a comparative study of four transportation projects in the United States. In addition, a detailed implementation framework was validated and further developed through a Delphi study with representatives from several organizations whose major responsibilities and experiences include the management of change in procurement approach. Findings from these studies, including application to the construction industry and other industries are presented.

M.Tech. (Engineering: Civil) / Please refer to full text to view abstract

Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Civil Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Includes bibliographies. / Ph.D.