Met Office confirmation of hottest summer underlines need for a concrete solution

The impact of England’s joint hottest summer was severe on its transport infrastructure. With climate change expected to make summer heatwaves more regular and more extreme, the built-in resilience of our roads, railway and runways needs greater consideration.

According to the Met Office, the summer of 2022 tied with that of 2018 for the warmest. This summer, however, went beyond that. It included record-breaking heat in July when temperatures in the UK exceeded 40oC for the first time with temperatures reaching 40.3oC at Coningsby, Lincolnshire. Future forecasts for the climate do not look good with the Met Office predicting that current heatwaves exceeding 32oC could by 2070 be exceeded by summer temperatures regularly reaching 40oC.

Extreme heat can result in asphalt pavements softening and melting leading to road and runway surfaces ridging and rutting as they become more susceptible to vehicle wheel loads. Most asphalt pavements will not begin to soften until they hit a temperature approaching 50oC. However, even a sunny day with temperatures in the mid 20oC can be enough to generate on-ground temperatures of 50oC as the dark asphalt pavement surface absorbs a lot of heat and this builds up during the day. During heatwaves when temperatures regularly reach 30oC the potential for asphalt pavements to melt is significantly increased.

During the July 2022 heatwave, asphalt roads throughout the UK were reported to be melting. Similarly, flights were stopped at RAF Brize Norton in Oxfordshire and Luton Airport in Bedfordshire when the tarmac runways melted. The impact of the high temperatures was also felt on the railway network with timber sleepers at Battersea, London, catching fire.

“The impacts of climate change has meant that the extreme could become the average”, said Joe Quirke, chairman of Britpave, the infrastructure industry association. “These means that our transport infrastructures must have greater built-in resilience to minimise the impact of excessive heatwaves.”

Modern continuously reinforced concrete pavements, when designed and maintained properly will not melt, catch fire or rut

It is more resilient to summer heatwaves than asphalt.

This stiffness and ability to carry traffic loads remains for the performance life of the concrete pavement. Concrete roads, runways and rail systems thus provide better environmental and whole life economic solutions.

Britpave is calling upon government and infrastructure clients to recognise these oft -forgotten benefits of concrete to ensure long-term infrastructure performance and resilience to weather events that are predicted to become the norm rather than the one-off.