Dustboss valuable at mall demolition In the US one of the Wash<strong>in</strong>gton, D.C. area’s most experienced demolition contractors has successfully controlled extensive dust while tak<strong>in</strong>g down the old Waterside Mall, a 4-storey, heavily re<strong>in</strong>forced concrete structure totall<strong>in</strong>g approximately 111,500m 3 . Crews were able to suppress surface dust and airborne particles with portable high performance mist<strong>in</strong>g equipment, despite the crowded urban location and close proximity to the local Metro station tunnel entrance <strong>in</strong> what has been called a surgical demolition project. Eng<strong>in</strong>eers from Wreck<strong>in</strong>g Corporation of America knew that the densely populated area and close proximity to rema<strong>in</strong><strong>in</strong>g structures would require extraord<strong>in</strong>ary precautions. “The Metro station entrance has a Buy well, crush well, Downwell A UK based demolition contractor has reaffirmed its faith <strong>in</strong> Extec with the purchase of a new C-10+ track-mounted mobile crusher. Replac<strong>in</strong>g an exist<strong>in</strong>g C-10, the unit jo<strong>in</strong>s an Extec C-12, itself a replacement for an earlier model, <strong>in</strong> the grow<strong>in</strong>g fleet of Downwell Demolition. The C-10+ was purchased to allow the company to work efficiently on <strong>in</strong>ner city sites, particularly <strong>in</strong> and around London, where space is at a premium. “I must admit I was nervous about tak<strong>in</strong>g on another crusher <strong>in</strong> the present economic climate, but we are lucky enough to have a comb<strong>in</strong>ation of a very loyal client base and a good bus<strong>in</strong>ess reputation, which has enabled Downwell to cont<strong>in</strong>ually expand. We have plenty of work and projects on the books for 2009, and I am <strong>in</strong> no doubt that the Extec crushers will play a big part <strong>in</strong> that cont<strong>in</strong>ued success,” says Downwell Demolition founder Matt Phillips. The C-10+ was commissioned on site at the Quantum House redevelopment <strong>in</strong> Croydon, Surrey, a four-month contract to demolish and recycle a seven storey office block. The C-10+ was then sent to K<strong>in</strong>gsnorth Power Station <strong>in</strong> Kent where it processed a mixture of concrete and slag on a seven week contract. “Almost without exception, demolition waste is now processed on site and left for future 46 PDi • Is s u e 1 - 2009 • Fe b - Ma r c h way of creat<strong>in</strong>g a vacuum,” says Wreck<strong>in</strong>g Corporation of America executive vice president Terry Anderson. “If the w<strong>in</strong>d is blow<strong>in</strong>g the wrong way, the dust gets sucked right down. The site was also hemmed <strong>in</strong> on three sides by structures that needed to be preserved, so we had to do a very selective removal, while protect<strong>in</strong>g the entire surround<strong>in</strong>g area from the nuisance and potential hazard of airborne dust.” After research<strong>in</strong>g possible solutions, Anderson decided to rent a DustBoss DB-60. As the largest of the suppression designs from Dust Control Technology, the unit atomizes water droplets to the optimum size for particle capture, launch<strong>in</strong>g them 60m or more with a powerful 25 HP fan that generates nearly 850m 3 /m<strong>in</strong>. With its built-<strong>in</strong> oscillation, the DB-60 Atlas Copco renovation <strong>in</strong> Mumbai An Atlas Copco CC 2500 U was <strong>in</strong>volved <strong>in</strong> the renovation of the Wankhede Cricket Stadium <strong>in</strong> development,” says Matt Phillips. “The two Extec mach<strong>in</strong>es enable us to process all construction and demolition waste <strong>in</strong>to Type 1 or 6F2 very efficiently, which makes them not only environmentally friendly but also extremely cost effective.” www.extec.eu can effectively cover nearly 2,000m 2 with a f<strong>in</strong>e, dust-trapp<strong>in</strong>g mist. The DB-60 is a fully automatic ducted fan mounted on a wheeled carriage so it can be easily located to accommodate w<strong>in</strong>d direction or specific work areas. The unit delivers adjustable elevation from 0-50° and a 40° oscillation range, provid<strong>in</strong>g crews with outstand<strong>in</strong>g coverage. “The droplet size is critical to effective suppression,” says Dust Control Technology chief executive Mumbai, India. The stadium needs to be renovated for the 2011 Cricket World Cup f<strong>in</strong>als. Shri Ganesh Construction, a subcontractor of Supreme Infrastructure India Pvt Ltd, Mumbai, was carry<strong>in</strong>g out the necessary demolition works. The Mumbai Cricket Association decided to demolish most of the northern and western stands of the stadium and improve the dra<strong>in</strong>age of the ground. The capacity of the stadium will be <strong>in</strong>creased from 35,000 to 39,000 seats and the entrance will be enlarged to make access and departure of spectators safe and easy. The ma<strong>in</strong> aim is to give every spectator a clear view of the match apart from comfort and world class facilities. Any corner of the stadium will have free view of the ball cross<strong>in</strong>g the boundary l<strong>in</strong>e. Wankhede Stadium was built <strong>in</strong> 1975 and is surrounded by residential build<strong>in</strong>gs and skyscrapers and the Mumbai western railway track passes close to the stadium. Due to noise and vibration levels the use of hydraulic breakers was prohibited. The authorities <strong>in</strong>stead accepted the use of a CombiCutter for the demolition work. officer Edw<strong>in</strong> Peterson. “Dust particles tend to be <strong>in</strong> a fairly narrow size range, so the water should be atomized to droplets near that same size for maximum attraction. Our standard models produce droplets from 50-200 microns, but all of our units are designed to be easily customized for target<strong>in</strong>g specific particle sizes or for cool<strong>in</strong>g applications.” The takedown WCA began the project <strong>in</strong> November of 2007, and the old structure did not go easily. “This was one of the more difficult build<strong>in</strong>gs we’ve taken down <strong>in</strong> some time,” says Anderson. “We had to fight down every step.” WCA employed a high-reach excavator for the general demolition work, a 45t Komatsu PC400 with a 26m boom. K<strong>in</strong>shofer dedicated shears with 360º rotation were used for cutt<strong>in</strong>g the approximate 5,000t of re<strong>in</strong>forc<strong>in</strong>g. Anderson’s crews also made extensive use of a 90t truck crane and wreck<strong>in</strong>g ball. “It’s a technology that virtually never breaks down,” he said. “And it leaves a small carbon footpr<strong>in</strong>t.” WCA also used a 63t Caterpillar 365 excavator to take down the structures, along with three Hitachi 450 excavators with bucket attachments and four Hitachi 330 excavators with a variety of attachments that <strong>in</strong>cluded concrete pulverisers and demolition hammers. WCA performed all concrete crush<strong>in</strong>g and recycl<strong>in</strong>g on-site, with an Extec C10 crusher used to process approximately 53,500m 3 of material. The crushed product was used for non-structural fill and backfill<strong>in</strong>g. “By nature, concrete work generates a lot of dust,” says Anderson. “We felt we had to take strong measures for control on this project. The DustBoss did such a good job that we decided to purchase the unit.” www.dustboss.com About 7,000m 3 of re<strong>in</strong>forced concrete had to be demolished with<strong>in</strong> a project time of three months. “I completed the job on time and am very satisfied with the performance of the CombiCutter CC 2500 U. I am happy with sales and service support given by Atlas Copco,” says Shri Ganesh Construction owner Phoolchand Jaiswal. The CC 2500 was equipped with universal jaws, which are fitted with teeth for break<strong>in</strong>g concrete and with blades for steel cutt<strong>in</strong>g. All blades and teeth are replaceable. It fits on carriers from 22-35t and weighs 2,640 kg. With maximum oil flow of 250 l/m<strong>in</strong> the cutter achieves open<strong>in</strong>g cycles of 3 sec and clos<strong>in</strong>g cycles of 2.8 sec. www.atlascopco.com
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