New ideas to 'reverse the rot' on roads

Roadmender Asphalt’s chief executive officer, Harry Pearl, gives Highways his take on how we can ‘reverse the rot’ in local roads maintenance once we come out of lockdown.

As we look ahead to the future, the roads sector has turned to the principle of ‘building back better’. Making sure we emerge from the pandemic even stronger is the right approach; and where better to start than the local maintenance backlog?

With little funding visibility to plan asset management over the next five years and an £11.14bn mountain to climb, we may not be off to the best start, but innovations in materials and techniques may be able to help.

Enter Roadmender Asphalt and its new Elastomac system – a thermoplastic innovation that includes nine end-of-life tyres recycled into every tonne.

The system has been through years of preparation and extensive road trials and has now received Product Acceptance Scheme (PAS) approval from Pavement Testing Services (PTS).

Mr Pearl says: 'We have a quality management system and factory production control processes for the material in place and have gone through extensive performance testing on things like adhesion, texture depth and skid-resistance.'

The technology is the latest product to join the rubberised market but, while Tier One companies are hoping to lay stretches of asphalt with crumb rubber additive, Elastomac is for instant repairs.

First announced early last year, Mr Pearl argues that it represents a new and long-overdue shift in how we think about repairing roads. Namely, treating repairs differently from building a road.

He tells Highways: ‘For the last 100 years people have used the same material that is designed for building roads to fix roads. So, the whole process is inefficient. We waste loads of time collecting asphalt from hot-mix plants and the only way we can get the asphalt to stick is by cutting out the hole and compacting the hell out of it. How about we change that thought process and switch to using products that are designed for fixing roads?'

Comparing the different techniques, Mr Pearl argues: ‘Rather than having to spend time square cutting and excavating potholes before filling them with glue-covered aggregate that takes hours to collect, has a five-hour shelf life and then requires vibratory compaction, potholes can now be filled with a purpose-designed flowable repair material that’s made from sustainable recycled materials. It is heated on site, welds itself to the existing road, and delivers a totally waterproof permanent repair with no edges that can fail.

‘By avoiding excavating the patch, the process requires on average 80% less material with no waste to carry away, meaning that – subject to the geography of the workflow – contractors should be able to complete up to five times more patches per day at a significantly reduced cost.’ He makes a good case and while the defect repair technique of square cutting and relaying has its benefits when done right first time, it is a long process and not suited to the kind of joint and crack treatment you might need if you want to blitz a stretch of road before applying surface dressing.

With so much time lost for surface dressing last year, and this year's season fast upon us, solutions like Elastomac can help the sector catch up with the workload and get ahead.

The Elastomac laying process can be taught in two days to any road operative and satisfies the Highways Sector Council’s guidance on the recovery – namely, that councils should be accelerating shovel-ready work. Mr Pearl tells Highways: ‘Elastomac is good for anything from joints, to cracks, to shallow surface defects, to potholes, and work around manholes. You could start with Category 2 and 3 defects and where you do surface dressing. If you don’t fix cracks before you do the surface dressing, the cracks will re-emerge in weeks. The best way to make use of surface dressing is to make sure the defects have been repaired before.’

As Mr Pearl points out, mastic asphalt has a long history dating back to pre-Roman times, when it was used for things like waterproofing ships. More and more councils are starting to take an interest in flowable thermoplastics, Mr Pearl says, while similar products are also becoming popular in the US.

Apart from being suitable for shallow surface defects and pre-surface dressing, Mr Pearl also hopes mastic will be taken up by utilities, particularly in broadband trenching, where it can help accelerate the road works behind fast speed connectivity – another issue given impetus by the coronavirus crisis.

All this amounts to his conclusion that using fixing technologies rather than building techniques for repairs ‘could reverse the rot and eat into the £11.14bn backlog’.

‘In fact, we could end up eliminating it – we can catch up and go past it.’

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