New additive boosts rubber-modified asphalt

Lehigh Technologies, which produces micronized rubber powders, has joined forces with additive specialist Rheopave to come up with a system which will improve the performance of asphalt, while reducing the cost compared to standard polymer modified asphalts. Rheopave had developed its X10 additive, a blend of reactive polymers and other elements, to work with Lehigh’s MicroDyne micronized rubber powder. It overcomes two problems currently experienced with rubber-modified asphalt, according to Lehigh’s direc
September 10, 2014 Read time: 3 mins
The LeHigh product offers high performance in use

7875 Lehigh Technologies, which produces micronized rubber powders, has joined forces with additive specialist Rheopave to come up with a system which will improve the performance of asphalt, while reducing the cost compared to standard polymer modified asphalts.

Rheopave had developed its X10 additive, a blend of reactive polymers and other elements, to work with Lehigh’s MicroDyne micronized rubber powder. It overcomes two problems currently experienced with rubber-modified asphalt, according to Lehigh’s director of coatings, asphalt and construction materials Ryan Alleman.

“The first problem is that rubber does not become part of the asphalt so it settles out. So the contractor needs to be near the plant or to fit his equipment with agitators, which is expensive,” he said. “The second issue is that base asphalts have become more robust because refiners are taking out the aromatic oils for other uses.

This means that ground tyre rubber isn’t able to modify the asphalt as well as it used to.”

Rheopave X10 works by generating active sites on the rubber particles allowing a continuous network structure to be created, suspending the rubber throughout the binder. This means it is stable in storage and transportation.

Performance benefits from using the combination of Lehigh’s MicroDyne and Rheopave X10 are longer fatigue cracking life and also enhanced elastomeric properties allowing the pavement to combat cold cracking, according to Alleman. It is also easier to handle as the mix is less tacky than one made with ground tyre rubber alone.

Though this is a new product, it is already available commercially in Florida, with over 18 companies around the US currently involved in testing it. Lehigh has also begun promoting it in Europe, Japan, Korea and Brazil. “We will initially be targeting countries that have experience of rubber-modified asphalt already,” said Alleman.

In terms of cost, this product could offer savings over conventional SBS-modified bitumen, although that will depend on the prices of SBS and how robust the base asphalt is and therefore how much additive it needs. SBS prices have historically been volatile, although they are currently low as there is no shortage in supply.

Hot mix plants looking to use the combination of Rhepave X10 and Lehigh’s MicroDyne may need to invest in modifications. “It does not require a high shear mixer like that which is needed to process SBS however it does require a terminal blender and a saw-toothed blade such as a Cowles Mixer blade,” said Alleman.

“Companies that have blenders can expect to outlay less than $5K in plant modification to process Rheopave.”

Materials

For more information on companies in this article

Related Content

  • Benninghoven’s burning ambition for LEP’s future
    September 30, 2013
    Benninghoven, the leading asphalt plant and accessories manufacturer, believes the greater use of Lignite Energy Pulverized (LEP) during asphalt plant production will ensure huge long-term financial savings for plant operators currently using alternative combustibles. Guy Woodford reports The claimed impact of LEP on the German asphalt plant market is impressive. As reported in the July-August 2013 issue of World Highways, 80% of all asphalt plants operated in the country are said by LEP Europe-wide
    Read More
  • Energy Saving Roads - The Future Way of Sustainable Infrastructure
    April 23, 2019
    A workshop into environmentally-friendly road construction was held in Denmark - report from Mikkel Bruun, Bruun Communication Recent advances in road construction have included the development of climate asphalt, which reduces rolling resistance and saves CO2. But what is it and how does it affect the production and use of asphalt pavements? And what are the socio-economic implications? The ROSE project that just ended with a workshop in Copenhagen might hold the answers. The rule of thumb is that lo
    Read More
  • Machine control boosting paving quality
    April 27, 2015
    The use of machine control technology on a bypass construction job has boosted quality quality control is a topic that clients as well as contractors are finding increasingly important. Control systems are being used more and more often on construction sites as a result, so as to collect data on a range of processes. This includes looking at the asphalt being supplied to site and on the quality of paving during construction. Using this data, processes can be optimised in the medium-term and, in the long-ter
    Read More
  • IRF World Congress: Road user charging
    October 16, 2024
    Where will the money come from to develop and maintain tomorrow’s sustainable road network, no mater in what nation? This was the focus of another session at the IRF World Congress in Istanbul of day of the three-day event.
    Read More

Highlighted Content