Saving costs in infrastructure projects
RUBBLE MASTER Compact Recyclers from Austria are the cost-effective solution for mobile processing: compact, high performing and ideal for a wide range of applications. They produce homogenous, cubic, high-quality grain from construction waste and natural rock on-site economically and can be transported without special permits. This cost-effective process has proven to be extremely beneficial in road building, and this is because you can produce graded aggregate in a single pass with just one mobile machine solution and only one feeder. The following examples show you how this works out:
RUBBLE MASTER RM80 revolutionises autobahn refurbishment
A RUBBLE MASTER impact crusher weighing only 23 t demonstrated the remarkable results than can be achieved in road building applications. In the course of the refurbishment of the A3 autobahn near Passau, a cost-effective alternative to conventional processes was developed together with RUBBLE MASTER with a view to no longer having to remove the entire old concrete surface (in a time-consuming and expensive process), with lorry load after lorry load going to an intermediate storage site for it to be processed and screened in a mostly stationary plant, only for it to be then returned to the job site. Thanks to the track-mobile RM80 and a revolutionary method, it was possible to counteract the cost pressure through on-site recycling!
In a mere 4 weeks, a 1.2 kilometre stretch of the northbound carriageway on the A3 Autobahn near Passau was refurbished cost-effectively in a single operation with the help of the RUBBLE MASTER RM80. The mobility of the crusher was supported perfectly by the patented RUBBLE MASTER oversize grain separator. Half the carriageway was removed in the process and the entire material was fed into the crusher by the excavator loader, which gradually moved backwards (heading northbound) along the carriageway as work progressed. The finished graded material in a defined grain size of 0/45 mm was discharged onto the substructure and then levelled. This is how the RUBBLE MASTER power system mastered the logistical challenge directly on-site, without any intermediate storage. Between 50 and 60 linear metres of autobahn were completed every day, by crushing, screening and immediately reusing around 4,600 m3 of concrete in total.
Patented RUBBLE MASTER system
The patented RUBBLE MASTER OS80 oversize grain separator combined with the high-throughput impact crusher RM80 was used to produce defined aggregate in a single pass. The OS80 is easily fitted to the crusher's discharge belt using quick-release levers, maintaining unrestricted movement of the crusher around the site. A defined grain size of 0/22 mm to 0/63 mm is achieved in a single operation (screening only once) from asphalt, concrete or natural rock. Three comb-cascades ensure that any oversize material is separated in full from the end product. Power is supplied from the crusher generator. Only one low-bed trailer is required to transport the entire system.
This method has also been successful in extending the motorway network in Estonia. In the spring of 2005 a motorway project was launched for a new 90 km long stretch from Tallinn to St. Petersburg. The carriageway was broken up along a 5 km stretch of the entire width of the first carriageway while the second carriageway was used for the traffic flow. Here too, the excavator loader took up its position on top of the broken material and fed the track-mobile RUBBLE MASTER crusher, using its crawler gear to reverse slowly and form a pile of crushed material which was later spread across the carriageway and flattened. This way it was possible to crush the asphalt on-site down to 0/40 mm for it to be reused cost-effectively at the same place again. All in all 110,000 tonnes of asphalt were processed in 100 days – 120 t/h on average. The project was completed on a section-by-section basis.
Mobile recycling of broken-up roads containing tar
Thoma Bau- u. Recycling GmbH & Co. KG based in Lower Bavaria has earned success thanks to the mobile recycling of bituminous material. And they have counted on a RUBBLE MASTER RM100 since 2007. "Because tar has to be fully recycled," says Robert Thoma junior, describing the challenges. "We process the broken-up roads that contain tar with a mobile crusher operating directly on the customer's job site. The excavated material is then crushed in the RM100 down to the required aggregate size, mixed and a binder and water are added in accordance with the acceptability test, resulting in an environmentally safe and stable top layer in road building. Over 200 t/h of ready-to-use 0/32 mm graded material were produced from broken asphalt material at a road building operation near Giessen (see picture, right) – with only one operator required for the track-mobile RM100, combined with the mobile oversize grain separator OS100.
The mobile RUBBLE MASTER dynamic duo was also in action in 2007 in a new road building project in the Bavarian Forest. The old road was excavated in the process and stored on a nearby site. Some 2,500 tonnes of bituminous blocks also containing hard rock gravel were recycled on-site to make 0/32 mm aggregate which was then reused as a 15 cm thick foundation layer. The entire material was processed in only 2.5 days, including set-up and removal.
Standardised grain in a closed circuit
The RUBBLE MASTER power system is also available as an indispensable add-on for the RM100 which, together with the OS100 mobile oversize grain separator, delivers high-value, standardised aggregate in a single pass. Using a closed loop system with integrated oversize grain refeeding you can produce even more of the desired grain fraction and increase performance, thanks to the continuous feeding with coarse blocks and oversize grain. The OS100 screens reliably thanks to 4 comb cascades. The advantage here – and also the starting point in the product development – is the fact that the crusher can be operated at maximum throughput, with a large crushing gap and low wear impact. The oversize grain separator is ready for operation in just 10 minutes. This way, RUBBLE MASTER users are able to fulfil the necessary tasks and requirements on all job sites and in any surroundings cost-effectively, and use the outstanding quality to earn a reputation as recycling specialists.
__________________________
approx. 6,300 characters / 1,000 words. Photos to be used with copyright. Proprietor: RUBBLE MASTER HMH GmbH, Austria.
Published: December 2008