One of UK’s first ‘net zero roads’ laid in Chippenham
The road had been dubbed 'Chippenham's worst'
A street recently dubbed the “worst road in Chippenham” has become one of the first in the UK to be produced meeting net zero standards.
Ladyfield Road in Chippenham was dubbed the town’s “worst road” with residents suffering damage and discomfort by cracks and potholes.
To residents’ relief, the road was resurfaced in October.
But what only became clear this week is that the road surface was part of a trial between council contractors and academics to create a ‘net zero’ road surface.
The secret carbon-busting ingredient is biochar, a waste product from the biomass industry.
In the case of the product used in Chippenham, straw waste that had been used to power boilers to heat industrial greenhouses was superheated in a vacuum – locking in carbon rather than releasing it into the atmosphere.
Biochar makes up about seven per cent of the road surface material. The contractors also used UK-produced steel slag, a by-product of the steel industry, rather than virgin material. This means that less aggregate is imported – another win for the environment.
The top of the new road surface material was Milepave, which produced at lower mixing temperatures than traditional Tarmac, requiring less energy and bitumen – which is derived from crude oil.
The scheme used 871 tonnes of Milepave across 8,216m² of road surface, cutting carbon by 40 per cent – equivalent to the carbon emissions of 10,000 litres of diesel.
And the road was sealed with a special asphalt grout that stops water getting into the road surface – making cracks and potholes far less likely.
Highways contractors Miles Macadam and Atkins revealed the innovative techniques used to achieve net zero standards in a video posted this week, and confirmed that Ladyfield Road had been chosen as “one of a handful” of trial sites across the UK.
Wiltshire Council confirmed that the cost of including biochar in the materials increased the cost of the road resurfacing project by just five per cent.
With the civil engineering industry and councils having targets imposed on them to lower their carbon emissions, researchers at Aston University in Birmingham – who are trialling the new road surface solutions with Miles Macadam – say that using the nation’s roads as a ‘carbon sink’ – sequestering CO2 so that it is not released back into the atmosphere – could be one solution to help tackle the climate crisis.