Reduced-temperature asphalt

The main difference to conventional hot asphalt is the processing and installation temperature. In figures, that means a temperature reduction of 20–40 °C. Some of the accompanying effects in production and use include an improved total energy balance, for example, as well as a reduction in emissions during manufacturing and lower figures for workplace exposure levels when installing the asphalt.

The temperature reductions sought after in asphalt production are brought about by a temporary reduction in bitumen viscosity, which can be achieved by the addition of water or additives.

Bitumen (the binder) cannot actually wet/envelope the mineral component until about 140 °C – its viscosity is simply too high at lower temperatures. The fluidity or viscosity also depends on the specific bitumen used and can vary widely between different types of bitumen. Since viscosity is temperature- and type-dependent, hard bitumen has a higher viscosity at the same temperature than soft bitumen. A standard temperature range is between 140 °C and 180 °C, and typically around 150–160 °C.

The reason for achieving a binder viscosity that’s low enough is to ensure good wetting and enveloping of aggregates in the mixer. The smoothness of the asphalt mixture also plays an important role when installing the road surface and ensuring the asphalt can be compacted.

On the one hand, low bitumen viscosity can be achieved withFoam bitumenor theUse of additives.

This is another area where BENNINGHOVEN is your trusted partner. From our FOAM BITUMEN MODULE to dosing systems for feeding a wide variety of additives to your process, we have the answer to your individual requirements. Thanks to Plug & Work, a retrofit can be completed quickly and easily for any kind of plant.