Reduced-temperature asphalt

The crucial difference compared to conventional hot asphalt is processing and laying temperature. In numbers, this is a temperature reduction of 20–40 °C. The accompanying effects in production and application include the improved energy balance and the reduced emissions during production, as well as the lower workplace exposure during laying of the asphalt.

The temperature reductions sought after 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. In addition, the elasticity of the asphaltic mixture plays an important role during the asphalt laying process and the compactability during laying.

Low viscosity of bitumen can be achieved through the foam bitumen technology or with additives.

BENNINGHOVEN is your reliable partner for this as well. 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. With Plug & Work, the system can be quickly retrofitted to any plant at any time.