New materials can revolutionise the way in which we build tunnels.
If a car drives into a tunnel wall, the material in the tunnels should also handle such impacts without the consequential damage of the accident becoming too great.
Traditionally, tunnel walls and ceilings have consisted of PE foam sprayed over with concrete. New products are in the pipeline. Products that have good insulation properties are fire-resistant and weigh less than one tenth of the weight of concrete.
See more in the link below.