Icivili Enjiniyering SeptemberSSteptem be 2010 Vol 18 No 8 W I N N E R 2 0 0 9 FOR EXCELLENCE IN MAGAZINE PUBLISHING AND EDITORIAL TTransportationransportation EEngineeringngineering BBenen SchoemanSchoeman FFreewayreeway NNanotechnologyanotechnology iinn ppavementavement eengineeringngineering GGautrainautrain ccommencesommences ooperationsperations oonn aairportirport llinkink EECSACSA nnoteote oonn rrolesoles aandnd rresponsibilitiesesponsibilities iinn tthehe pprofessionrofession Icivili Enjiniyering September 2010 Vol 18 No 8 W I N N E R 2 0 0 9 FOR EXCELLENCE IN MAGAZINE PUBLISHING AND EDITORIAL CCOVEROVER AARTICLERTICLE Transportation Engineering Ben Schoeman Freeway Nanotechnology in pavement engineering Gautrain commences operations on airport link ECSA note on roles and responsibilities in the profession IsiNdebele ON THE COVER Technology that had previously been used for cold foaming of bitumen was adapted for successful use in an ordinary continuous drum mix asphalt ON THE COVER plant for the manufacturing of Warm Mix Asphalt by National Asphalt. The Using a conventional drum plant to produce Warm Mix Asphalt plant seen on the cover is situated at National’s Cliffdale operation near National – turning the cold foam process into warm asphalt 2 Shongweni in KwaZulu-Natal OPINION BOOK REVIEWS The Motorist’s Paradise 74 Innovation – changing the tools of the trade 6 A guide to South Africa’s mountain passes and poorts 75 TRANSPORTATION ENGINEERING Ben Schoeman Freeway 8 MARKET PERSPECTIVE Infrastructure construction spend after Icivili Enjiniyering September 2010 Vol 18 No 8 Potential applications of nanotechnology 2010 – where to now? 76 in pavement engineering 14 PUBLISHED BY SAICE Block 19, Thornhill Offi ce Park, Bekker Street, Vorna Valley, Midrand Private Bag X200, Halfway House, 1685 Proposed Sandton Transportation Framework 21 Tel 011-805-5947/48, Fax 011-805-5971 http://www.civils.org.za MARKET CONTRIBUTION [email protected] State-of-the-art Transport Operations Centre Mixed-use developments 78 EDITOR Verelene de Koker for the 2010 FIFA World Cup 26 [email protected] Tel 011 805 5947/8, Cell 083 378 3996 New directions in the design of unbound IN BRIEF 82 EDITORIAL PANEL Marco van Dijk (chairman), Irvin Luker (vice-chairman), granular layers in road pavements 34 SANRAL deploys Road Survey Vehicle to detect Ali Naidu (SAICE president), Wally Burdzik, Johan de Koker, Jeffrey Mahachi, Jones Moloisane, Eben Rust, Michelle Theron, Marie Ashpole, Zina Girald, Verelene potential problems on the road Ramping up de Koker (editor), Cathy van der Westhuizen (editor’s Implementation of interactive Web-based assistant), Barbara Spence (advertising), Dawie Botha and sitting down Concor adds to inner city (SAICE outreach) training tools in pavement engineering 44 infrastructure Never as straightforward as it ANNUAL SUBSCRIPTION RATE SA R575.00 (VAT included), International US$ 122.00 Will traffi c congestion always be part of our lives? 48 first appears Specialist construction company ADVERTISING Barbara Spence, Avenue Advertising wins prestigious award Businesswomen’s [email protected] Determining long-term parking needs at Tel 011 463 7940, Fax 011 463 7939 Association acknowledges Linda Ness South Cell 082 881 3454 OR Tambo International Airport 52 African Women in Engineering – motivating, DESIGN AND REPRODUCTION Marketing Support Services, Menlo Park, Pretoria Transportation Research and Education celebrating and empowering women PRINTING Ultra Litho, Johannesburg at the University of Pretoria 58 The South African Institution of Civil Engineering accepts no responsibility for any statements made or SAICE AND PROFESSIONAL NEWS opinions expressed in this publication. Consequently Injecting a rapid rail link into a metropolis 62 nobody connected with the publication of the magazine, Engineering Council of South Africa – a note on roles in particular the proprietors, the publishers and the editors, will be liable for any loss or damage sustained From dreams to reality – Gautrain commences and responsibilities in the engineering profession 88 by any reader as a result of his or her action upon any statement or opinion published in this magazine. operations on airport link 68 GCC 2010 – using a Supplementary Agreement 90 ISSN 1021-2000 Precast concrete noise barriers make SAICE’s Spring Book Sale 91 sound sense for Gautrain 71 Diarise This 92 Civil Engineering | September 2010 1 1 ON THE COVER National – turning the cold foam process into warm asphalt In the local asphalt industry, and MANUFACTURING AND PAVING in particular amongst members National has been involved in these trials from the outset through its road mainte- of the Southern African Bitumen nance contract with eTh ekwini. As with anything new, nothing happens without Association (SABITA), there are a willing client, and it was only through very few people who have not the vision and dedication of the engineers of the Roads Provision Department of heard of the Warm Mix Asphalt eTh ekwini that this project was made (WMA) trials that are happening possible. Th rough the high skills input of the entire team, and in conjunction with in Hammarsdale, eThekwini. This a very well put together template, the risk process started back in 2008 under to the City was minimised to an almost negligible level. Th e fi rst two trials were the auspices of what became carried out on roads where rehabilitation the Warm Mix Interest Group of was needed, and which also needed a full investigation and rehabilitation design, to prove and verify actual cost benefits, South Africa and which comprises targeting a 20-year life cycle. but the environmental and other prac- client bodies, consultants, asphalt Krishna Naidoo of the Roads tical benefits already make it seem like a Provision Department was adamant that very worthwhile exercise. manufacturers and contractors, the City would not accept anything that During the fi rst trials on Brackenhill technology suppliers, as well was below the standard of conventional Road, the asphalt was supplied from Hot Mix Asphalt (HMA). This stance National’s plant at Cliff dale and the com- as other relevant and related is also in line with the broad-term pany also did the paving of the asphalt on parties. A lot has been written and definition of WMA, which in essence site. Th e asphalt on Leicester Road was requires and specifies a quality standard supplied from Much Asphalt’s Coedmore published about the success of of “at least the same if not better” than plant, while National again carried out the these trials, which are currently in conventional HMA. With this quality on-site construction work. objective in mind, the intention is to the third stage of roll-out, following produce and pave asphalt at tempera- THIRD TRIALS on the first trials at Brackenhill Road tures of around 20 to 30 degrees Celsius For the third set of trials National was lower than HMA, thus bringing about again tasked with producing mixes in November 2008 and the second all the benefits of a lower carbon foot- from its Cliffdale plant and also with at Leicester Road in June 2009 print, as well as related benefits such as the actual on-site paving. Mike Walsh, cost reduction. A lot still has to be done Contracts Manager for National says: 2 Civil Engineering | September 2010 “One of the biggest challenges on these what their chosen careers could have 1 On site in Hammarsdale where the warm trials is to get all the information prop- in store,” says Frank Swift, Regional asphalt mix is being applied erly and accurately recorded and logged. Manager for National. A lot was learnt from the first trials, The third trials are being carried out Warm Mix Asphalt. Wynand explains: resulting in many more staff members over a substantially longer period and ”Foaming of bitumen happens when performing very specific recording in include numerous different mixes, some very hot bitumen comes into contact the Leicester Road trials, and again even including recycled asphalt (RA) with water at ambient temperature. The now.” This approach has been taken to content of as high as 40%. “It is also ‘explosion’ that occurs literally turns the the next level on the current trials by quite something to get such a variety of bitumen and water into foam, and this employing ten engineering students, mixes out of a single plant, this whilst foamed bitumen then achieves better mainly from the Durban University it is still producing asphalt for the coating of the stone aggregate particles of Technology, to assist. “Not only do commercial market as well,” says Deon when they are mixed together.” these students record data, but they are Pagel, Business Development Manager The foaming of different bitumen also given practical in-house training, of National. binder penetration grades was first exposure to the laboratory designs and It was during the roll-out of this tested with a laboratory foaming plant testing, as well as exposure to the on- third set of trials that Wynand Nortje, at a commercial laboratory. It was site lay-down areas. Interaction with Technical Manager at National, took the then decided that 60/70 penetration the Project Engineers is the cherry concept of ‘cold foaming’ to new heights grade was the best proposition, taking on top and really gives them a feel for by adapting this technology to produce into consideration National’s normal Civil Engineering | September 2010 3 2 Mike Walsh, Contracts Manager for National bitumen usage and available storage developments relating to Warm Mix Asphalt, checking and recording the asphalt facilities. At the asphalt plant, foaming but also to share the South African mat temperatures with an infrared camera is achieved by means of a bitumen and experience with counterparts abroad. 3 The lower asphalt temperatures water chamber or ‘pot’ that is fitted Th e tour, which had been arranged by result in much more pleasant working to the inside of the continuous drum SABITA, promises to bring back a wealth conditions for the paving crews mixing plant.