Low-temperature asphalt

Low-temperature asphalt

Low-temperature asphalt is asphalt that is produced and processed at a lower temperature without any negative impact.

The crucial difference compared to conventional hot asphalt is the processing and laying temperature. In figures, this is a temperature reduction of 20 – 40 °C. The accompanying effect 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.

Focus on temperature.

* Deutscher Asphaltverband e.V., asphalt Leitfaden, Temperaturabgesenkte Asphalte [Asphalt guide, low-temperature asphalts – published by the German Asphalt Association]

Facts at a glance.

Low-temperature asphalt

Environmental protection

> High energy savings
> Reduced emissions

Saving resources

> Lower total energy requirement
> Lower fuel consumption

Health and safety

> Reduced vapours and aerosols during hot processing of bitumen
> Reduced workplace exposure
> Protection of workers during production, transport and laying
> Lower heat impact for personnel
> Compliance with new workplace limits

Gentle on the material

> Reduced ageing of the bitumen binder
> Gentle on structural elements due to lower thermal load
> Lower wear on the asphalt mixing plant


> Expanded delivery radius
> Longer transport times possible

The paths to low-temperature asphalt

The desired temperature reduction during asphalt production is achieved by temporarily reducing the bitumen viscosity, which can be obtained by adding water or additives.

A temperature of at least approx. 140 °C is required for the bitumen (binder) to wet/coat the mineral. At lower temperatures, its viscosity is too high. The flowability, i.e. the viscosity, also depends on the bitumen type and can therefore vary greatly between the different bitumen types. Viscosity depends on temperature and type, i.e. hard bitumen has a higher viscosity than soft bitumen at the same temperature. Common temperatures are between 140 °C and 180 °C and the typical temperature is around 150 °C to 160°C.

A sufficiently low binder viscosity requires good wetting and coating of the aggregates in the mixer. In addition, the elasticity of the asphaltic mixture play an important role for laying and compactability during laying of the asphalt.

Low viscosity of bitumen can be achieved by the technology on the one handFoam bitumenand by usingadditives on theother hand.

Foam bitumen module

By mixing hot bitumen with water in the foam bitumen module, the bitumen is foamed to many times ofits original volume. This means that a large surface not only lowers the viscosity, but also improves the wettability of the aggregate material.
For the technical implementation, the weighing and mixing section simply has to be expanded with theFOAM BITUMEN MODULEwhich is additionally flanged onto the mixer cabinet and the bitumen weigh hopper.
Uncomplicated connection usingPLUG & WORKensures fastinstallation and commissioning.

Solid additives

In order to add smaller amounts of solid additives, BENNINGHOVEN offers the technical solution of thepowder/granulate feed system. Depending on the material and added quantities, additives can be dosed into the mixer with a stream of air. Themulti-variable feedis another option. This patented technology features precise dosing (exact weighing system) and allows larger additive quantities to be added to the mixer. The materials are fed with an elevator or inclined conveyor.

Liquid additives

With theadhesive system,up to two liquid additives can be added to the process. The system is equipped with two conveying pumps which dose the liquid additives into the bitumen weigh hopper and/or into the mixer. The system has a very good resistance to chemicals and high temperatures.

BENNINGHOVEN is your reliable partner for this as well. Whether with the FOAM BITUMEN MODULE technology or by adding various additives with feed systems – we have the answer to your individual requirements. With Plug & Work, the system can be quickly retrofitted to any plant at any time.

Sustainability by Benninghoven

Working more efficiently with sustainable and economical technologies is the challenge of today and tomorrow. Benninghoven offers a variety of innovative solutions for increasing sustainability in asphalt production.

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