The country’s asphalt industry could cut its carbon emissions by almost 40 per cent before 2020, thanks to new technology currently under development through an industrial and government collaboration.
Companies including Tarmac Limited, United Asphalt and Aggregate Industries have partnered with the Carbon Trust to invest more than £1.7m in projects that could wipe a combined 339,000 tonnes of carbon off the asphalt industry’s annual footprint within 10 years.
Tarmac Limited is working with Nynas, Atkins and MIRO to demonstrate semi-warm and cold-mix asphalt. The majority of UK asphalt is currently produced at around 170°C. It is claimed lower-temperature cold-mix and warm-mix asphalt requires less energy to produce and can be driven on much sooner.
According to estimates provided by the Carbon Trust, cold mix can reduce road works by anything up to 12 hours, cutting congestion and disruption.
Taking a different approach to energy savings, United Asphalt is working with Shell Bitumen and Berkshire Engineering to maximise the amount of reclaimed asphalt that can be used in road resurfacing. This is done by combining warm-mix asphalt and a new aggregate dryer.
Elsewhere, Aggregate Industries will install an Econotherm-developed heat-recovery system at its Haughmond Hill site in Shrewsbury. The system utilises waste heat to pre-heat the air combusted in the asphalt burner, which in turn reduces energy consumption.
Aggregate Industries plans to perform trials that will tackle issues such as moisture and dust in the recovered hot air; the company will also test heat-recovery technology to reduce the carbon emissions from the burner that heats and dries the aggregates. This is the main energy consumer in the hot-asphalt manufacturing process.