Mobile concrete solutions for tunnel construction 08 Sep 2016

Demand for super-mobile concrete mixing solutions is driving the well-established Austrian firm SBM firmly into the tunnel construction sector.

The company, based in Oberweis in the Austrian Alps, is benefitting from interest in its innovative solutions from among some of the world’s leading tunnel construction firms including Porr, Strabag, Metrostav and Marti Tunnelbau.

EUROMIX mobile concrete facility at the Goetschka Tunnel portal in Austria

Recently, SBM completed delivery of its twelfth EUROMIX^® concrete mixing plant to Europe’s largest mobile concrete producer, MBK.

As well as delivering mixing solutions for the production and delivery of large volumes of concrete to remote locations, the ever-increasing need for contractors to meet 'green' CO₂ emissions targets as part of their contractual obligations to project owners is establishing demand for mobile rather than traditional fixed concrete mix solutions.

SBM has been delivering both fixed and mobile concrete mixing, as well as ore processing facilities for decades, and over time has repeatedly delivered internationally recognised mixing plants for even higher concrete quality.

Meeting tunnelling demands

But the specific demands on concrete production set by the tunnel construction industry are not just restricted to issues of supplying it to a quality that can withstand high ground pressures, as well as resistance to freezing temperatures, road salt and fire.

Delivery of high volumes, and at exactly the right time that it is required at the tunnel face, is equally important – so an ideal solution is to produce it directly at the tunnel portal using mobile concrete mixing plants. This is an enormously demanding task. The logistics of production, as well as the supply of concrete ingredients, must be precisely coordinated, with overall concrete quality maintained at a constantly high level regardless of what can be – depending on the location of the jobsite – wildly fluctuating external temperatures.

With all this in mind, concrete production at the construction site using SBM’s supermobile EUROMIX^® concrete mixing plant has the effect of reducing CO₂ emissions by around 25%. The cost savings to be gained from the faster operational readiness of the plants – which can be erected on site and ready for operation in just eight hours – can also be significant. Furthermore, and as a result of the technology employed by SBM, there is no compromise on the quality of outputted concrete when compared to a fixed mixing solution that might be located many miles away from the jobsite and therefore require large numbers of truck movements to bring the product to site.

Multiple configurations of the EUROMIX system

The EUROMIX^® system

A wheeled mobile EUROMIX^® system has no need for fixed foundations. The twin-shaft mixer of the EUROMIX^® 4000, for example, achieves an output of up to 170m³ of hardened concrete per hour. With their robust and fully galvanised steel construction, all EUROMIX^® systems are designed for reliable 24/7 all-year round operation, and in all climate zones. Customers can choose from a range of five EUROMIX^® power classes, depending on the demands of the project in question – from the 2200 with a capacity of 100m³/hr right through to the 4000 with a capacity of 170m³/hr.

Additionally, and thanks to the modular design of the EUROMIX^®, plant expansions or upgrades such as higher hopper volumes, additional silos or winter equipment are achievable at any time.

"SBM concrete mixing plants are not only the number one in Europe for tunnel construction sites, but also for us at MBK. The many millions of cubic metres of best quality concrete produced by SBM speaks for itself," said Horst Wiener, Managing Director of Mobile Betonkonzepte GmbH (MBK), Europe's largest mobile concrete producer.

Total solutions

In addition to its concrete mixing plants, SBM is the only company in the sector that also offers “total concepts” for tunnel construction sites. Total concepts means that first class solutions for overall material management have been developed for the processing and conveying systems. In this way, SBM solves one of the greatest challenges in tunnel construction: the processing of excavated material, which after preparation can be reused as high-quality aggregate for further concrete production.

With this in mind, SBM has developed a seamless and interdependent quality system that encompasses the whole production chain. It ranges from crushing, screening and conveying to washing, dewatering and storage; right through to the mixing of high-quality concrete and its delivery. The benefits to the client are both environmental and financial, with the potential for large savings on the need for additional resources such as gravel pits, storage sites and transport routes.