While the prospect of walking in a winter wonderland may be quite attractive to some of us, the prospect of icy and snowy roads is less exciting for drivers, and even more of a headache for those responsible for maintaining and operating our road network.
Snow and sub-zero temperatures are bad news for road surfaces for a number of reasons. The biggest cause of damage to roads over winter is likely to be due to freeze-thaw action, where water runs into a crack, freezes and expands and hence widens the crack. And then that happens over and over.
Another potential issue when temperatures fall is that the property of the road surfacing material changes. When bitumen gets colder, it tends to get more brittle, making it more susceptible to cracking. Clearly, it is possible to design mixes that can cope with cold temperatures – there are asphalt roads in far colder climates than ours – and additive and bitumen technology are constantly advancing. But widening variations between summer and winter temperatures could mean that new mix designs are needed here in the UK.
The most common way to deal with the prospect of icy or snowy roads is to apply salt before ice begins to form or snow starts to fall. As some may remember from elementary chemistry lessons, adding salt to the road helps because it lowers the freezing point of water.
Countries where snow is a far more common occurrence than in the UK have been investigating other ways to banish snow and ice from their roads. The Netherlands, for instance, has been looking at ways to heat roads for well over a decade, using pipes or heating elements embedded into the road surface, a bit like underfloor heating. A recent scheme there saw a 1.7km-long cycle lane warmed by excess heat from a nearby paper plant.
Another option is to tackle the issue of ice with chemistry. Italian specialist Iterchimica has come up with an asphalt additive that lowers the freezing point of ice. Called Winterpave, it has been trialled on roads in Italy and in South Korea.
Of course, the best way to avoid cracks and potholes is preventative maintenance. Applying a surface dressing or microsurfacing closes off tiny cracks before they become a problem.
And if potholes or larger cracks do exist, it’s best to fix them as soon as possible. The Thermal Road Repairs system is one option for doing that, which has the added benefits of creating no waste and requiring very little new material. Heating up the asphalt in and around a pothole, mixing it with a little new asphalt and then compacting it all means that there will be no cracks for water to run into so there won’t be a repeated failure in the same location. All that means its low carbon too.
Thermal Road Repairs is a green technology company which supplies systems to improve the quality, cost and time efficiency of road repairs and paving – at a far lower environmental cost than traditional methods. It invests significantly in R&D, to create new technologies and to continuously improve existing ones.
Thermal Road Repairs: Decarbonising the asphalt repair industry.
High output. Zero emission. Zero waste. Permanent solution.