New road building method could save money and energy
27/01/2014 Highways Reporters
Lafarge Tarmac and the Carbon Trust have identified a new low energy method to build roads.
The process reduces energy costs, as well as cutting carbon emissions by up to 39%. The trial has identified potential savings of tens of millions of pounds; depending on the uptake across the road building industry.
Already, the West Midlands Highway Alliance, representing 14 local authorities, has committed to use the new method to help reduce its CO2 emissions by 20% by 2015.
According to the Carbon Trust and Lafarge Tarmac, the findings of the three year study to improve the carbon efficiency of the manufacture of road materials, show that the method has the potential to save the UK road industry £46.2m in energy costs over the next 10 years.
The conventional road material, commonly used across the UK, is made by bonding aggregates and bitumen into asphalt by heating them to temperatures of 180 to 190 degrees celsius. This project successfully trialled the use of a ‘low temperature asphalt’ (LTA) material, which allows mixing and working at lower temperatures. It bonds road materials as effectively as the conventional method, but using much lower temperatures and less energy.
The trial has enabled the project team to develop specifications for use, which will help accelerate the production and adoption of lower temperature asphalts. The project was led by Lafarge Tarmac and the Carbon Trust (within its Industrial Energy Efficiency Accelerator (IEEA) programme). Funding came from Lafarge Tarmac and the Carbon Trust (via the Department of Energy & Climate Change (DECC) and support from the Department for Business Innovation and Skills.
Al-Karim Govindji, technology acceleration manager for the Carbon Trust, said: “Roads are the lifeblood of economic prosperity: they connect people to jobs and business to markets. There is tremendous potential for this project, given the scheduled improvements to our major roads and motorways. This programme is an example of how by establishing new models of working, we can unblock demand-supply stand-offs, to help the UK to deliver the infrastructure of the future, at a lower cost for taxpayers and the climate.”
Martin Riley, managing director for Lafarge Tarmac’s asphalt and aggregates business, added: “As a leader in sustainable construction solutions, we want to use our expertise to help bring these solutions to our clients and customers. This project with the Carbon Trust will help unlock barriers to bring lower temperature asphalt into wider use. It will take time for these materials to become available, but as producers follow our lead and adopt this technology, there will be a growing movement to embrace LTAs as direct replacements for conventional hot asphalts.”
If the new specification is adopted and low temperature asphalt market achieves 21% of the total UK asphalt market over the next decade, it could save £46.2m and around 260,000 tonnes of CO2 during the manufacturing of these materials over the next 10 years. This would create the equivalent carbon savings of taking more than 345,000 cars off the road.
The new specification is also of great importance to the highway authorities, especially those that have set targets for the reduction of carbon emissions. For example, the West Midlands Highway Alliance, which represents 14 of the region's Local Authorities with a combined annual spend of over £400m, launched a concordat in September 2013 to reduce CO2 emissions in the production of road and footway materials by 20% by 2015.
Dr Nizar Ghazireh, the project director at Lafarge Tarmac, said: "This pioneering project and the development of the national specification for LTA will fundamentally change the asphalt industry in the UK, producing sustainable low carbon products. The developed specification will assist clients to procure these materials as standard products and that feedback from their use will inform the future development of the European Standards.”
Other project partners include Nynas UK, Atkins, MIRO and TRL. Out of the project a new specification, open to all manufacturers, has been published by the Transport Research Laboratory (TRL) in October 2013, enabling LTA mixtures to be designed and specified. The outcome from this project is likely to generate significant interest from both local and national highways authorities and their supply chain, given it proves the efficiency of road building can be enhanced without compromising performance.
Whilst the lower temperature asphalt technology is available today, the market shift to adopt it will be gradual, as companies need to invest significant capital in installing equipment; thus the energy savings from producing LTA will accrue over time.