The Met Office has placed yellow weather warnings in some parts of Scotland and the North as up to 20cm of snowfall is expected in the coming days. A œsignificant sweep of snow is expected to fall across the UK from today, and bitter winds and thundery rain will also be a reality for many Brits as wintery temperatures really start moving in following the mild November. While this weather could make travel more hazardous, the cold weather presents more than just slippery conditions. It can lead to more road defects than at any other time of year.
Potholes continue to cause despair and anger for motorists up and down the land, with these menaces costing British car owners £4bn in repair costs annually. As the winter months draw in, Britain is now entering prime pothole season. Such is the gravity of people wishing to see the back of them, the Government announced a £2.5bn fund in the most recent budget to tackle the issue. But this however still begs the question; what forms a pothole, and why do they continue to happen?
Potholes occur from a combination of both traffic and water. Roads are constructed in layers. The top layer is water-resistant and curved to drain water off the road and onto the shoulder. A road surface develops cracks due to the stresses caused by traffic and because of the heating and cooling of the surface. During the day, the sun warms the roadway causing it to expand a small amount, while nighttime cooling causes the road to contract.
Even small cracks in the surface allow water to seep below the surface into the underlying materials. During the cold nights the water freezes and expands. During a clear sky day, the sun warms the road which melts the underlying ice. The melted water can flow to a different section of the roadway. When the ice melts, the pavement contracts and leaves gaps in the surface under the pavement, where again water can get in and be trapped.
Stresses on the roads from traffic can widen existing cracks, allowing more water to seep in and freeze during the night. This freeze-thaw cycle will weaken the surface. Traffic over the weak spot in the road causes the roadway material to break down, and when that broken-down material is removed by constant traffic, it creates a pothole.
Once a pothole is formed, repair must take place to stop them increasing in size or causing more than just surface-level damage. The problem with pothole repairs is they are carried out using a process built around materials designed for building roads rather than fixing them. As a result, the process is more costly, inefficient and ineffective than it needs to be, rather like playing squash with a tennis racquet. You can do it but it's far from ideal.
Now, however, smoother roads are on the horizon. Innovative SMEs have started to ask why are pothole repairs filled with the same materials made to build roads when they can fill potholes with materials made specifically for the job.
Harry Pearl, CEO of Roadmender Asphalt, a sustainable road repair SME discusses new innovations that recycle roads, and provide for permanent pothole repairs.
"After a decade of austerity, councils have naturally gravitated towards innovation and have helped launch R&D hubs, working with innovative SMEs. Together, SMEs and councils have started to ask why road improvement tasks can't now be fulfilled with innovative and modern practices. We are now finding with councils that these innovations are trickling down into all aspects of road upgrades.
At Roadmender Asphalt we are developing our new Elastomac product that will continue to be trialled with councils post-lockdown. 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 5-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, is heated on-site, welds itself to the existing road and delivers a totally waterproof permanent repair. By avoiding excavating the patch the process requires on average 80% less material with no waste to carry away meaning contractors are able to complete 5 times more patches per day at a significantly reduced cost."