Tarmac changes asphalt ‘recipe’ to low temperature in net zero drive

June 20, 2022

Low carbon asphalt is set to become a feature of UK roads as Tarmac makes the most significant sustainable improvement to its ‘recipe’ for highway materials since the business perfected the method of making road surfaces stick in the early twentieth century.  

The company, whose original founder Edgar Hooley first patented traditional hot mix asphalt in 1902, is set to move its production to ‘warm mix’ which will help to save 13,500 tonnes of carbon dioxide each year – the equivalent of around 22,000 flights between London and New York.  

From July 1, 40 of Tarmac’s asphalt plants across the UK will default to warm mix for all lower layer materials as the company becomes the first in its industry to phase out traditional hot mix asphalt for highways projects.   

With one in three roads in the UK containing Tarmac products, the UK’s leading sustainable building materials and construction solutions business is calling on the highways sector to embrace warm mix materials to help decarbonise the nation’s roads.  

Warm mix temperature asphalt technology has the potential to reduce the embodied carbon of asphalt by up to 15 per cent compared to conventional hot mixes. The principle behind the technology is that lower temperatures are used to manufacture the material, using less energy and therefore emitting less carbon. 

The lower temperature material also enables road projects to be delivered faster than when using traditional materials. The asphalt is delivered cooler than hot mixes, therefore takes less time to reach trafficking temperature. This means that the road can be opened up to 90 minutes earlier to traffic, reducing disruption for road users. 

The reduction of programme durations will also increase the productivity of roadworks. 

Brian Kent, technical director at Tarmac, said: “While warm mix technology has been widely available to our customers over the past five years, against the backdrop of the climate emergency, we are now proactively switching our plants to offer this low carbon material as our standard and preferred option.   

“This is a significant sustainability-focussed improvement on Edgar Hooley’s original process, but it embraces the innovative spirit of our founder which remains at the heart of our business along with our clear commitment to help the UK transition to net zero.” 

The All Party Parliamentary Group on Highways has indicated that if the UK embraced low temperature manufacture for asphalt production it would cut at least 61,000 tonnes of CO2 a year – the equivalent of cutting almost 300 million miles of car journeys.