PORR is opening Austria’s most innovative asphalt mix plant at its site in Vienna’s Simmering district. The hot gas generator manufactured by Benninghoven works on the counterflow principle, ensuring maximum recycling addition rates with minimum emissions. The burner fires into the hot gas generator and heats the circulating air in the recycling drum. The hot air provides gentle and indirect heat to the recycled asphalt until it reaches its the final temperature. A recycling rate of up to 100% is now possible.
Helping reduce CO2
“With this, we are helping reduce the carbon footprint”, says PORR CEO Karl-Heinz Strauss. “Technology like this is an essential part of our circular economy strategy. We’re striving to replace primary raw materials with recycled materials wherever economically viable and technically feasible”. PORR currently recycles 2.8 million tonnes of material across the Group every year. In addition to asphalt, this includes bricks, building rubble and much more. PORR’s own construction sites and plants already use 1.6 million tonnes of recycled materials instead of primary raw materials.
30,000 tonnes of asphalt each month
PORR produces up to 30,000 tonnes of asphalt mix per month in Simmering, making it one of Austria’s largest producers. “The market is unequivocal in its demand for environmentally friendly construction materials and we are constantly receiving enquiries from customers”, says Strauss. “The quantities of used asphalt that we now process in the new mix plant depend on how much is available due to road renovations”. The first step is to double the proportion of recycled material to 40%. Another priority is proving that the asphalt produced meets the standards for values such as rutting resistance and load-bearing capacity. It must also fulfil customer requirements.
PORR is developing methods for lowering temperatures
For PORR, the opening of the mix plant is another milestone in the circular economy. PORR is also continuing to innovate in the field of asphalt research and development. Strauss: “We are researching how to reduce temperatures in the production of asphalt mixes in order to significantly cut energy requirements and CO2 emissions”.
Bautech Labor GmbH, a PORR subsidiary, has a two-pronged approach: Firstly, additives are added to the binder during bitumen production so that the viscosity changes, meaning that the temperature can be lowered during mix production. Secondly, it has also been possible to implement the modification directly at the asphalt mix plant itself. With impressive results: “If we lower the temperature of the mix during production by 30 degrees Celsius, CO2 emissions fall by around 22 percent”, explains Strauss. This also increases occupational safety as the vapours and aerosols during installation are reduced by as much as 70%.
