Cumbria Live Lab - trials with Shell a first for Europe
Matt Waning, project lead for the Cumbria Live Lab, talks about their new partnership with international energy company, Shell.
Cumbria’s Live Lab is investigating the sustainability and suitability of using additives derived from waste plastics as part of our highways surfacing programme. We are aiming to reduce our carbon footprint and provide a more resilient road network. The trials carry out real world tests using new highways technology and methods on local roads, which could revolutionise the highways and waste industry.
Working with our surfacing partner Hanson, we are beginning another chapter, developing trials with Shell. This is the first time Shell Bitumen’s LT R will be trialled in Europe so it’s really exciting for us and the whole Live Labs programme.
The highways industry has significant environmental impact in terms of carbon footprint, and the use of oil-based products and quarried material. We believe it is incumbent upon us as an industry to seek new and innovative ways to reduce environmental damage.
Shell’s product uses an additive derived from chemically modified recycled waste plastic. Lab testing has shown that using chemically converted plastic waste has no detrimental effect on performance and has good miscibility in bitumen. It can be used to lower the production temperature required for asphalt, so offers significant CO2 savings (up to 40%) when compared to conventional hot mix.
The circular economy principles have long been an integral part of the road construction industry and Shell describe them as follows:
- The recycling of end-of-life products and of waste have been illustrated in particular by the recycling of old roads and use of RAP (reclaimed asphalt pavement) as a substitute for a portion of the new material. Moreover, by incorporating secondary products in the formulation of bitumen and asphalts, the road construction industry contributes to putting to use the waste from other industries, helping them close their loops too.
- Extending the lifecycle of a road is possible due to the optimised product formulations and the polymer-modified bitumen that enable the production of longer-lasting and higher-performing asphalts.
- Improved resource management can be achieved by using low-temperature binding agents and asphalts that help cut back on energy consumption.
Shell Bitumen started its circular economy research programme aimed at developing technologies that reduce waste and pollution, and ensuring that pavements are kept in service for longer, in 2018. As part of this programme, an agreement was put in place with a company producing additives from end of life plastics. Additives were assessed for their suitability for use in bitumen and asphalt mixtures, and in the laboratory potential formulations were identified.
The first trial pavement was carried out in the United States and the new technology was chosen as the main binder for extensive civil engineering works.
We began works on the first trials in May 2021 on the outskirts of Nenthead, one of England’s highest villages situated in the North Pennines. Cumbria has some of the most extreme weather and challenging terrain in England with extreme cold, with high rainfall and flooding, as well as high mountain passes and heavily traffic urban roads. We, along with our partners, wanted to test the materials to their limits and we feel like we are doing that with this site.
When we laid the material, as with any other trials we have done on and off the network, we also laid a control section. This allows Cumbria and its partners to monitor the material against ‘normal’ material.
Early indications are positive; the asphalt was mixed as designed at a lower temperature, around 30C lower. The material was laid without issue, despite the material being significantly cooler than normal. Hanson, the contractor who laid the materials were equally happy with the trial to date.
Because the plastic additive is preblended into the bitumen, a full tank had to be purchased and Cumbria utilised the remaining bitumen by adding a further surfacing scheme to the trial. As with the Nenthead trial, these have been successful. An added benefit of the Shell Bitumen LT R product is the reduced laying temperature, which means the roads can be opened quicker reducing the closure period thus reducing disruption to the network
Cumbria are continuing to work with Shell and Hanson and are currently looking at options for additional sites to trial the product.