RSTA News
COOL ASPHALT PROMISES SIGNIFICANT CO2 REDUCTIONS
A series of pilot projects aimed at cutting a third off carbon emissions of road works and cutting the time taken to carry them out has been welcomed by the Road Surface Treatments Association (RSTA).
The pilots will be carried out by the Carbon Trust and will examine how to reduce the heat needed to mix asphalt – currently 170o C is required. Cooler asphalt will significantly reduce the energy needed to produce it and, as it will harden faster, could cut the time taken for road works by up to 12 hours. The tests will examine heat recovery technology to reduce the carbon emissions from the burner that heats and then dries the aggregates. This is the main energy consumer in the hot asphalt manufacturing process. A further benefit of using cooler asphalt is the reduction of many health and safety risks associated with using higher temperature materials.
The pilots are being carried out by leading road surfacing companies including RSTA members Aggregate Industries and Nynas. As part of the pilots, Aggregate Industries are to install an innovative heat recovery system at its Haughmond Hill site in Shrewsbury. This will cut energy use by using waste heat to pre-heat the air combusted in the asphalt burner. By 2020, this system could be used to save 33,000 tonnes of carbon every year. Nynas is working with a consortium including; Tarmac Quarry Materials, Atkins and MIRO to provide demonstration projects of semi-warm and cold asphalts. A further consortium comprising United Asphalt, Shell Bitumen and Berkshire Engineering will examine how to maximise the amount of reclaimed asphalt which can be used in road resurfacing by combining warm mix asphalt and a new aggregate dryer.
The Carbon Trust and UK asphalt industry believe that the pilots could point the way to reducing 339,000 tonnes of carbon off the industry’s annual carbon footprint by 2020. That is the equivalent of a 39 percent reduction.
“The road surface industry is actively examining how to provide more for less, not only in terms of cost but also in terms of carbon emissions”, said Howard Robinson, chief executive of RSTA.
“The Carbon Trust and its partner companies are to be congratulated for their ‘can do’ vision and innovation. The pilots have the potential to make a very significant difference.”
