A HIGH-QUALITY ELASTOMER BITUMEN AND ASPHALT MODIFIER
Road+ is an elastomeric bitumen and asphalt modifier, manufactured in compliance with a process patented by Evonik. Ingredients are high-quality rubber powder produced by Genan mixed with 4.5% Vestenamer®, a semicrystalline polyoctenamer produced by Evonik.
Laboratory tests and road projects show that as a rule of thumb, a standard bitumen modified with minimum 10% Road+ performs at the same level as or even better than a similar 4% SBS-modified bitumen. When comparing properties, e.g. the ability to prevent rutting and forced ductility, Road+ performs significantly better.
It is of great importance for product performance that the rubber powder used is clean and uniform in size. Being the world’s largest manufacturer of rubber powder from scrap tyres, Genan has the technology to live up to these requirements. Genan ambient rubber powder is not only consistent in size – but also virtually dust-free.
Follow the links below to download further information on Road+.
Throughout the world, both local and national authorities are now realising that it is good business to use modified asphalt for new road projects. It is cost-efficient both medium- and long-term, as rubber-modified roads are less exposed to both rutting and cracking. This reduces the need for maintenance, which is not only a financial burden, but also a traffic-related problem, as roads must be partly closed during maintenance work.
Asphalt and bitumen modification is thus becoming more and more popular. In several European countries, more than 20% of all bitumen for road construction is now modified. Follow the link below to download statistics published by the European Asphalt Pavement Association.
Traditionally, the most common way to modify bitumen in modern road construction has been to use virgin SBS (styrene-butadiene-styrene). It was thus a major breakthrough, when Genan launched Road+ as a third generation asphalt and bitumen modifier – based on recycled rubber powder from end-of-life tyres. In respect of both performance and properties, Road+ proved equivalent or superior to SBS modifiers. Yet, the environmental gain offered by the use of Road+ was probably even more significant. If a product based on ELT rubber powder could gain ground in the market for asphalt and bitumen, the environmental gains would be substantial. Compared to co-incineration, greenhouse gas emissions would be significantly reduced, and the use of fossil fuels would be limited. For further information about environmental aspects, we make reference to Genan’s Life Cycle Assessment (LCA) Study.
Road+ can be used in any asphalt application, be it stone mastic (SMA), all kinds of asphalt concrete (AC), porous asphalt (PA) or mastic asphalt (MA).
Unlike SBS, Road+ may also be used in any type of bitumen.
Road+ may be applied in SAMIs (stress absorbing membrane interlayers) at high concentrations.
Prof. Dr. Ing. Damm, Hamburg, scientific consultant for asphalt concrete research, states:
“Road+ modified asphalt improves the performance of all types of roads from smaller country roads over heavily trafficked motorways to industrial properties. The use of the Road+ system for all these different applications shows the full scale of its elevated technical properties.”
ROAD+ AND SUSTAINABILITY
A study prepared by the FABES laboratory in Germany has compared Road+ asphalt to both conventional rubber asphalt and non-modified asphalt. Results show that Road+-modified asphalt is the solution where the least organic material is washed out – in both cold-water and hot-water environments. Follow the link below to download the complete study.
FABES has also carried out an emission study for critical compounds, testing during production in the hot mix plant, as well as in connection with field testing. No emission of N-nitrosamines was detected, and the emission of volatile and semi-volatile compounds was lower for Road+-modified asphalt compared to conventional polymer-modified asphalt (PMB). Follow the link below to download a summary of this study.
An important property for asphalt is that it must be recyclable – without producing emissions during the recycling process. Follow the link below to download a study made by Heiden Labor in Germany, proving good recyclability of Road+ modified asphalt.
The use of Road+ ensures considerable savings in terms of both greenhouse gas emissions, acidification and cumulative energy demand. For further information, we make reference to Genan’s Life Cycle Assessment (LCA) Study.
A recent study prepared by the WHO (World Health Organization) Regional Office for Europe, quantifies the health risk related to the exposure to noise. The study shows that in the western part of Europe, the equivalent of one million healthy life years are lost every year due to traffic-related noise. In Europe, noise pollution is thus an environmental risk factor, the scope of which is comparable to air pollution. Not only does exposure to noise cause or contribute to discomfort, stress and sleep disturbance; it may also lead to high blood pressure, heart attacks as well as learning disabilities and tinnitus. Tests prove that the use of Road+-modified asphalt results in a noise reduction of up to 5-6dB compared to conventional asphalt. As a reduction of just 3 dB(A) is perceived by the human ear as comparable to half of the original traffic load, this demonstrates a considerable reduction.
FLEXIBILITY IN THE FIELD
NO COMPARISON WITH PREVIOUS RUBBER ASPHALTS Rubber in asphalt is not a new phenomenon. The concept has been tested on previous occasions – with mixed success. Nevertheless, the properties gained through the use of Road+ are far superior to those of earlier generations of rubber asphalt. The addition of Vestenamer® in compliance with the Evonik patent makes a world of difference.
Earlier generations of rubber asphalt were sticky, requiring special handling equipment. Road+-modified asphalt boasts extremely good adhesion to the aggregate – yet, it does not stick to neither tools nor tanks. There is no need to clean tanks and trucks with release agents. No special equipment is needed for the on-site handling of Road+-modified asphalt.
WIDER TEMPERATURE WINDOW Road+-modified asphalt may be applied at a wider temperature range than can traditional, modified asphalts. This is not only an advantage in case of compaction, but also in connection with manual operations, e.g. around driveways and on curves.
DELIVERY FOR WET OR DRY PROCESS?
ROAD+ FOR WET PROCESSING For wet processing, ambient rubber powder and Vestenamer® are delivered at the mixing plant or the bitumen blending facilities (terminal blending) as separate components. Moreover, ready-mixed bitumen from Shell is available (Shell Mexphalte RM).
ROAD+ FOR DRY PROCESSING For the use in hot-mix asphalt plants (dry process), Road+ is delivered in 20/25 kg sacks.
MIXING PROCESS FOR LABORATORY TESTING Please follow the link below to download test procedures.