Rapeseed asphalt
As RapsAsphalt or under the brand name RapsAsphalt a is asphalt denotes that an appreciable amount of rapeseed oil in bitumen content contains (canola bitumen emulsion). This asphalt was developed to replace the petroleum otherwise contained in bitumen and thus to obtain a more environmentally friendly and at the same time more cost-saving form of asphalt. RapsAsphalt was developed by the Austrian company Vialit Asphalt Ges.mbH & Co. KG (licensor) and patented in 1994. In Germany production and distribution are in the hands of ARGE RapsAsphalt eV
Manufacturing
Rapeseed asphalt is produced like normal asphalt as a mixture of the binding agent bitumen and aggregates and used for surface treatment in road construction. It only differs from asphalt in the composition of the binder.
Instead of the conventionally used soft bitumen solutions, hard bitumen is used, which is adjusted to a workable consistency by adding rapeseed oil. This bitumen containing rapeseed oil is processed into flux bitumen (for use in the hot process) or bitumen emulsions (cold process). According to the patent, the proportion of rapeseed oil in rapeseed asphalt is two to 20 percent, depending on the area of application and variety.
properties
Rapeseed asphalt has some properties that have a positive effect on the properties of the bitumen. The addition of 5% rapeseed oil to the asphalt reduces the viscosity and thus improves the wetting of the gravel . The hardening and the traffic stability of repaired surfaces is achieved faster with rapeseed asphalt, the aging behavior should be improved compared to comparable products. In addition, the biodegradable rapeseed oil is more environmentally friendly when washed out by rainwater than mineral-based oils that are hazardous to water. In contrast to conventional bitumen mixtures, rapeseed asphalt does not contain any plasticizers that could pose a health risk during processing.
A practical test of the asphalt carried out by the Technical University of Munich confirmed the good performance properties of the material and certified:
- After several years of inactivity and visual assessment, the four surface treatments examined are overall in a good to very good condition. Grain eruptions essentially only occurred where extreme loads are present from agricultural and forestry traffic.
Due to the trademark protection of the name "rapeseed asphalt", an analysis of the proportion of rapeseed oil and the differentiation between other oils and fats is necessary, which is very difficult to do due to the composition of the asphalt as a mixture of substances. A solution process with carbon disulfide made it possible to carry out an examination in the gas chromatograph and to analyze the admixture based on the fatty acid pattern to an accuracy of 0.5%. As the rapeseed asphalt ages, the fatty acid pattern changes, as fatty acids without double bonds react with the bitumen and accordingly change its properties, the aging process and the associated deterioration in binding properties is delayed.
Climate goals
In addition to the direct technical properties, the licensor specifies properties for the permanent reduction of greenhouse gas pollution. In contrast to petroleum derivatives, rapeseed oil is not of fossil origin. According to information from a recognized Federal Agency for Agricultural Engineering, around 6,000 kg of CO 2 per hectare of cultivated area are absorbed when rape grows; in Austria alone, an annual cultivation area of 6,000 ha could be used for road construction in the rural road network, thus binding 36 million kg of CO 2 annually . Since rapeseed is not burned in the context of asphalt production, its use as a road construction binder can achieve a real reduction in the greenhouse gas carbon dioxide by embedding it in asphalt.
Market situation
The first surface made from rapeseed asphalt was a federal highway with a motorway feeder function in 1992. The market launch in Germany took place in 2001 as part of a pilot project in Bavaria. Two years later, 1,900 tons of rapeseed bitumen emulsion were processed throughout Germany, in 2005 already 2,100 tons. For 2006 a decrease is expected. The reasons for the downward trend are seen in savings by the municipalities in road maintenance measures and in costs that are around ten percent higher than with conventional asphalt.
Rapeseed asphalt is mainly used in road repairs to this day, although according to results on a test construction site it can also be used for thicker asphalt layers. Forecasts assume that around three percent of the bitumen could be replaced by rapeseed oil, which corresponds to around 15,000 tons of rapeseed oil in Austria and 100,000 tons in Germany per year.
Vegecol
Rapeseed asphalt only replaces part of the oil in the bitumen with rapeseed oil. Based on this, Colas Bauchemie GmbH has developed a bitumen that is made entirely from renewable raw materials. The bitumen known as Vegecol or the asphalt made from it has so far only been used as a surface material for the Federal Garden Show 2007 in Gera and for park paths near Nymphenburg Palace .
Individual evidence
- ↑ Thomas Oligschläger: Raps: Composition in CO 2 major. New ways of road rehabilitation. In: CARMEN eV (2009): Yearbook 2008/2009 Renewable Raw Materials. Pp. 365f., ISBN 978-3-937441-20-7 .
- ↑ Company. In: vialit.at. Retrieved December 4, 2017 .
- ↑ Home Arge Rapsasphalt eV In: arge-rapsasphalt.de. Retrieved December 4, 2017 .
- ↑ a b c Klaus Tröster: Analysis of rapeseed asphalt. Vegetable oil 1/2009; Pp. 16-17.
- ^ Witzenhausen Institute for Waste, Environment and Energy GmbH: Nawaro-Kommunal - Rapsasphalt ( Memento of November 27, 2011 in the Internet Archive ).
- ^ Th. Wörner: Pilot project rapeseed - bitumen emulsion in road construction. Research report on behalf of the Klaus Geuder engineering office, Neusitz, June 2005.
- ↑ a b c Johann Bleier: Rapeseed oil in road construction - proven in Austria for 17 years. Vegetable oil 1/2009; Pp. 17-19.
- ↑ Vialit Asphalt GmbH & Co KG: Advantages ( Memento of the original from June 13, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. .
- ↑ Bettina Schmidt: RapsAsphalt - market situation. In: CARMEN eV (2007): Yearbook 2006/2007 Renewable Raw Materials. Pp. 365f., ISBN 978-3-937441-15-3 .
- ↑ Product data sheet from Colas (English) ( Memento of the original from May 19, 2014 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 28 kB).
