IMIESA - Volume 33, Issue 10, 2008
Volumes & issues
Volume 33, Issue 10, 2008
Source: IMIESA 33 (2008)More Less
Author Tony StoneSource: IMIESA 33 (2008)More Less
The recent and far-reaching consequences of the American subprime housing fiasco, which led to a number of well-known international banks closing their doors, and plunged the world into its worst financial crisis since the Great Depression, is a case study in voracity. It illustrates our capitalist-gone-wrong, consumerist, greed-driven affluenzic feeding frenzy where the pursuit of money and wealth is the overriding justification for all behaviour, and where the observance of law and ethics applies to everyone else but oneself.
Source: IMIESA 33, pp 6 –10 (2008)More Less
Municipal demand-supply gap widens
Citizens and municipalities should talk : local governance barometer : municipal mattersSource: IMIESA 33, pp 11 –13 (2008)More Less
A study released by Idasa in August found that despite significant improvements in service delivery by local government over the past ten years, most municipal councils face a widening gap between demand and supply of services. This has led to citizens losing confidence in local government as an institution that can meet their needs and respond effectively to the challenges they face.
Source: IMIESA 33, pp 14 –16 (2008)More Less
Source: IMIESA 33 (2008)More Less
Lean in the Public Sector was one of the exceptional presentations in the line-up at this year's Lean Summit Africa 2008, the lean management conference that took place in Cape Town during October. International presenter, Arjon van Lieshout, founding partner at House of Performance in the Netherlands, discussed the lessons learned from various Lean implementation projects in the public sector. IMIESA will feature a case study in the November / December issue.
Author Candice LandieSource: IMIESA 33, pp 18 –21 (2008)More Less
Held at Wits University and hosted by the Department of Sociology and the Amandla Forum, the discussion focused on alternative forms of public transport and drew representatives from the taxi industry, the Johannesburg Chamber of Commerce, the media and community associations.
Source: IMIESA 33, pp 22 –28 (2008)More Less
The population boom, expected to reach 5 million by 2020, and issues consequent of such a boom, would bring with it a number of challenges, one of which would be traffic congestion. If not adequately and proactively addressed, chaos would prevail.
As such, the Emirates of Dubai's Road and Transport Authority (RTA) commissioned Africon to undertake a traffic study to find best-practice solutions leading up to 2020. This project, valued at AED 2 million (R4,4 million), and now complete, is a showcase of world-class transportation planning and the development of comprehensive solutions for modern evolving cities.
Source: IMIESA 33, pp 29 –32 (2008)More Less
Finley Engineering Group, Inc. (FEG) of Florida is providing final design and construction engineering services for six segmental bridges on Israel's Road 431 project - the first in Israeli bridge construction history to use external tendons. FEG used LUSAS Bridge to analyse and optimise the pier and deviator segment diaphragms for the imposed loadings whilst keeping the segment weight within the 65 tonne lifting capacity of the contractor's equipment.
As a result of FEG's design the owner and contractor were provided with major benefits from simplified precasting details, thinner sections, rapid erection procedures and improved long-term durability.
Source: IMIESA 33, pp 33 –35 (2008)More Less
Given the design brief from South African National Roads Agency Limited (SANRAL), the client, the steel arch footbridge over the N2 at Plettenberg Bay was to create a safe, functional structure with a location and geometry that follows the preferred routes of pedestrians crossing the National Route 2 (N2). As Plettenberg Bay is a popular holiday destination, the brief also required the creation of a structure that added both aesthetic and functional value to the area.
Source: IMIESA 33, pp 36 –40 (2008)More Less
Source: IMIESA 33, pp 53 –62 (2008)More Less
Efficient road transport is dependent upon construction of high-quality roads. It is important that hot-mix asphalt (HMA) surfaced roads resist permanent deformation, or rutting, in order to provide a high level of service to the road user. In order to improve the resistance of HMA layers against permanent deformation, the Gauteng Department of Public Transport, Roads and Works (GDPTRW) has commissioned a multiphase study into the behaviour of different types of HMA under typical traffic and environmental-loading conditions. The study includes laboratory and field evaluation of a standard HMA mix, as well as different HMA mixes that were designed to be rut resistant.
In this paper, the focus is on the comparison between the permanent deformation behaviour of the standard HMA mix and one rut-resistant HMA mix of which the grading differs from that of the standard HMA mix. The permanent deformation has been monitored under traffic loading with the heavy vehicle simulator (HVS), and the temperature, under which the loading was applied, was varied. Other parameters, such as the binder type of the HMA, and load levels of the HVS, were kept constant to focus the attention on the effect of the change in grading of the HMA mix.
The data presented in this paper indicate that the grading of the HMA mix can play a major role in the resistance to the permanent deformation of the mix, even under severe temperature conditions. The potential rut-resistant benefit of coarser grading for HMA mixes have been supported through HVS tests. Further tests are required, both in the laboratory and field, to evaluate the durability and fatigue properties of the coarser HMA mix against the standard reference mix.
This paper forms part of studies towards a masters degree in technology at Tshwane University of Technology (TUT) of the third author. The outcome of the overall research will contribute to road owners and design engineers' better understanding the deformation mechanism and being able to plan, design and construct HMA pavements that are resistant to it. These results will also be incorporated into updated Guidelines for the Design of Hot-Mix Asphalt in South Africa.
Source: IMIESA 33, pp 63 –76 (2008)More Less
A general concern exists regarding the ability of the South African Hot-Mix Asphalt (HMA) design method to accurately predict the rutting performance of HMA designs through laboratory evaluation. Since 2000, various studies have focused on this issue, and several HMA mixes from construction projects and laboratory-prepared slabs were tested using a range of laboratory wheel-tracking tests to assess the rutting potential of the mixes. The data from these tests were compared with field performance of the HMA. Although some of the tests appeared to be well correlated with rutting in the field, there are at present no generally-accepted and quantified relationships to link laboratory test results to rutting in the field under variable traffic loading and environmental conditions. Other tests that are available for the assessment of rutting, such as the Axial Loading Slab (ALS), are essentially axial tests and do not simulate a rolling wheel load. These tests mainly evaluate the resistance of asphalt to volume change, and not shear response. Shear deformation is known to be the dominant mode of deformation causing rutting in pavements. It is also more sensitive to temperature and rate of loading than volume change.
In a current study on the development of rutting in a standard HMA mix under varying traffic and environmental conditions, the focus is on the evaluation of the effects of different compaction methods on the data obtained from a range of laboratory tests. The aim of this work is to provide input for the selection of appropriate and validated laboratory tests for the evaluation of rut resistance of HMA mixes.
In the paper, the background to the study is firstly provided, followed by a brief discussion on the parameters evaluated. Next, the data obtained from a range of laboratory tests on samples compacted using field and a range of laboratory compaction methods are evaluated and compared, and conclusions are drawn regarding the effect of compaction method on the data obtained from the various laboratory tests. This paper forms part of the research for an M.Tech degree at the Tshwane University of Technology (TUT).
Source: IMIESA 33, pp 77 –87 (2008)More Less
Increasing traffic volumes and a travelling public that is becoming more and more environmentally conscious, but intolerant to traffic delays, are common issues facing the authorities in urban areas across the world. This results in great pressure on engineers to develop more innovative ideas for long-lasting pavement repairs.
The situation in South Africa is no different, albeit on a smaller scale relative to countries like the United States. Repair on the urban roads in Gauteng is becoming increasingly challenging, especially when no capacity upgrade has been undertaken for a number of years. This is particularly true for the Ben Schoeman freeway which is the main link between Johannesburg and Pretoria.
This paper discusses some of the latest progress made in concrete technology as a result of these challenges. It focuses on the implementation of these technologies on the Ben Schoeman freeway, from design to construction. Many of the concrete pavements in South Africa are nearing the end of their design lives and implementing new repair methods, as well as sharing the good and bad experiences among practitioners, contractors and the client, is becoming increasingly important if not a must.
Source: IMIESA 33 (2008)More Less
Nedbank Corporate Property Finance : Affordable Housing has approved a loan facility to a subsidiary within the Safrich group of companies to install services and infrastructure for the top structure construction of 775 homes in Soshanguve East, ext 6, which is located north of the Rosslyn industrial area within the municipal boundaries of the City of Tshwane.