Decarbonising the asphalt repair industry
Local authority road repairs
Local Authorities
Thermal Road Repairs has extensive experience with and works across multiple councils within the UK.
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Our solution can be tailored to suit a variety of delivery methods such as contracting, self delivery or owner operated, meaning our repair method can be incorporated easily into a contractors toolbox.
Case study - Bath and North East Somerset
The challenge
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In late 2019 VolkerHighways used Thermal Road Repairs (TRR) technology to fix a test carriageway defect in the bus lane of a busy A-road in Bath. After 18 months, the repair remained intact and unchanged, at which point VolkerHighways and its client, Bath and North East Somerset Council (BaNES), decided to conduct a more substantial, one month trial, which was extended to two months, based on its impressive initial performance.
“We believe in the product, and we are keen to use it, but we wanted to see if we could get the outputs, prove it was cost effective and demonstrate the benefits that could be realised from it,” explains VolkerHighways project manager Kofi Agyen-Frempong. “Our client, needed as much data as possible to base any decisions on.”
The solution
In May and June 2021, TRR supplied a unit and crew to carry out planned and reactive repairs on both urban and rural roads in Bath and North East Somerset. VolkerHighways has been the highway term maintenance contractor for BaNES since 2019.
The TRR system uses a thermal infrared heater, which is charged by mains power and solar panels, to heat up failed and failing material in the pothole and surrounding asphalt. The existing asphalt is then mixed with a small quantity of new asphalt to create a homogeneous material and is then compacted with a roller.
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Because the asphalt around the edges of the pothole is also heated, there is no joint; the material all bonds together preventing the pothole from reforming. The patented TRR heating system comes with sensors and controls that carefully monitor the heat of the material beneath it, automatically switching off when the right heat has been reached. This is important, since overheating the bitumen makes it brittle and more likely to crack, something the VolkerHighways team will be watching out for in the repair zones over the coming months and years.
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The TRR repair process is also much faster than traditional techniques: there is no need for breaking out the defect, saw cutting or jack hammering. Also, there is no requirement for vehicles to take waste loose material away or bring fresh asphalt in. Everything is contained in the one repair unit.
The results
“Both VolkerHighways and BaNES are happy with the way the TRR technology performed,” says Agyen-Frempong, “we now need to weigh up the costs and benefits in order to decide whether and how best to use the technology in the longer term.”
There are multiple ways to procure the TRR technology: units can be purchased outright, leased, or the whole service including crew can be purchased. TRR provides training to contractor or council staff who would operate the unit.
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“Local authorities are definitely interested in methods that reduce the carbon footprint of repairs. Many of them have declared a climate emergency and they are now working on their action plans to reduce their carbon emissions.”
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One lesson that emerged from the trial is the need to carefully plan the order of works and the wider logistics. In terms of repair cost per pothole, the TRR technology worked out close to ‘cost neutral’, compared to traditional methods, however this could be reduced further in the future, explains Agyen-Frempong:
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“If there were a larger hot-box closer to the works, say in a depot, it would reduce the travel time required to load the unit with asphalt”, he says.
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Agyen-Frempong also observed that the technology worked more effectively on urban, rather than rural roads in this area: “With rural roads, the defects tend to be far more extensive, over large areas and sometimes with crumbling edges, which means that using a unit that heats a 1m-squared area or a 1m-by-2m area may not be the best method.”
Before
After
Case study - Richmond
The challenge
The London Borough of Richmond was looking for more efficient ways to carry out pothole repairs.
“The process we were using was inefficient, time consuming and costly and the quality output often not good,” says Nick O’Donnell, assistant director of traffic and engineering, who is driving an innovation programme in the Borough. “And we were getting a lot of complaints.”In an urban environment, noise, environmental constraints and disruption to road users and the community mean that traditional pothole filling techniques are not ideal. “You want to get in and get out – like the SAS,” says O’Donnell.
The solution
O’ Donnell came across the Thermal Road Repair (TRR) system at a conference and was able to talk to officers at Northamptonshire County Council who were using the system. “It’s always helpful to speak to officers in other authorities when considering new technology,” advises O’Donnell.
The TRR system uses a thermal infrared heater, which uses LPG and power gained from its in built solar panels, to heat up failed and failing material in the pothole and surrounding asphalt. The existing asphalt is then mixed with a small quantity of new asphalt to create a homogeneous material and then compacted with a roller.
Because the asphalt around the edges of the pothole is also heated, there is no joint; the material all bonds together preventing the pothole from reforming. The repair process is also much faster than traditional techniques: there is no need to break out the defect, saw cutting or jack hammering. Also, there is no requirement for vehicles to take waste material away or bring fresh asphalt in. Everything is contained in the one repair unit.
The next step for Richmond was to set up a trial where TRR could demonstrate to council members and technical staff how the system works. O’Donnell’s team then created a business case which showed that, using the council’s own operatives, cost savings of 40-50% could be achieved. The cost of the equipment could be paid back two years’ time.
The Borough’s members were also impressed by TRR’s environmental credentials. “It’s 80% more environmentally friendly than traditional methods – which is a big selling point for members,” says O’Donnell. TRR’s method producing an average of 0.4 tonnes of CO2 per eight-hour shift compared to 2.4 tonnes for traditional techniques*. Richmond purchased the TRR system in Autumn 2020. (*Since the time of this case study our metrics for carbon emissions have been refined and are now 0.5kgM2 as opposed to 3.5kgM2 by traditional methods)
The results
Due to changes internally, Richmond ran the TRR system using TRR operatives initially. “TRR has a number of operating models as to how it can be run as a system,” says O’Donnell. “They can operate it for you with trained- up gangs, they can train up your teams for you or train up a third party to run it.”
Employing TRR operatives, Richmond is achieving between 20 and 30% cost savings, says O’Donnell. The next step will be for TRR to train up workers from the Borough’s framework maintenance contractor. “We expect that this will push the savings up further,” says O’Donnell.