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"World record" in Engter harbour - Asphalt Mixing Plant
31. March 2010

The section of Autobahn 1 in North Germany running between Bramsche and Osnabrück-Nord will be widened this summer along a stretch measuring 6 kilometres. Johann Bunte Bauunternehmung GmbH & Co. KG of Papenburg is the contractor. The asphalt should have been supplied by a proprietary mobile plant with parallel drums. But that was not to be.

 

120,000 tonnes of asphalt were needed last year just for the A1 project alone. Work on the site continued around the clock: this called for a continuous production of asphalt in large quantities and of consistent quality. Bunte needs another 130,000 tonnes to process the remaining sections of the A1 by June 2010. Further construction measures on the A1 will follow. It was these conditions that led Bunte to place an order for a fourth Ammann mixing plant in the spring of 2009. No sooner said than done – so one might think. However, the first batch of asphalt, according to the ambitious plan, should be produced by mid-September. An apparently impossible schedule!


Systematic plan implementation

A location was quickly found: just three kilometres away from the A1, directly adjacent to the Mittelland canal near Engter. At the beginning of the year the site was still full of earth banks and hollows and more akin to an adventure playground as it had served as an intermediate earth landfill. Initial negotiations between Bunte and Ammann were held at the beginning of April. A month later the concept had been developed so far that it was ready for signing. The order was placed at the beginning of June and the project team commenced planning activities. But the task involved far more than installing a single plant as the plan was to turn the site into a modern asphalt production location. As Bunte was always in line with the time schedule with regard to building tasks, construction of the asphalt mixing plant was able to commence on 31 July. A project team managed by Ammann was selected to coordinate construction activities. The team convened once a week, made sure that work plans were consistently fulfilled and adjusted them where necessary – that was the key to success. Acceptance and commissioning took place at the beginning of September and the plant went into full-scale operation in mid September 2009.

 

Flexible plant in all its refinement

The Universal Next Generation asphalt mixing plant is 38 metres high and intended to produce 200,000 tonnes of asphalt per year. Its outstanding feature is a new concept for treating RA (reclaimed asphalt). The plant can heat 240 tonnes of asphalt granulate per hour. Experts refer to this technology not as a parallel drum but as a process gas drying and heating unit that works on a counter-flow principle. The material has no contact with the flame and is therefore heated more gently. The second plant of this type is currently operating in Engter. It enables the production of binder courses consisting of 100% asphalt granules. All of the aggregate is delivered by ship, hoisted into the silos by crane and then transferred directly to the boxes by conveyor belt. The only items delivered by truck are the other additives and the fuel, for instance brown coal dust. This is stored in two silos as both burners can work with BCD and domestic fuel oil. It is always better to have enough of the cheaper alternative in stock.

 

Unsurpassed speed

A workshop container has been integrated in the support structure of the asphalt granulate unit. Both make service and repair work much easier. The maintenance catwalks on all of the feed units run in parallel and are easily accessible. Calibrated weigh bridges were installed beneath the mixing tower to speed up the loading process. The vehicle routes for collections and deliveries are kept strictly separate. "Erecting mixing plants is no longer out of the ordinary for us", sums up Helmut Renze, Technical Managing Director of the Bunte Group. "However, one cannot emphasise enough just how fast this plant was erected." "World record" is what Renze likes to use best in this connection. The 15 jobs created here in such a short period of time have helped secure other jobs within the group now and in the future. For a construction company – which is what Bunte is first and foremost – to have its own in-house asphalt production facility has proved its worth. "Being able to offer everything from one source makes us particularly effective", says Renze.