Maintenance is a much higher percentage of this total cost, so Dr Jonkers expects big savings through extending the concrete's service life.

BBC: Key test for re-healable concrete

I'm sure everyone would like to join with me in extending our best wishes and our appreciation for the service she has given through her life.

BBC: Her Majesty is pictured with Prince Charles

It said that officials were considering extending the life of the RAF's VC10s - due to be retired from service in March - then using the Tristar, which goes out of service next year, to meet air-to-air refuelling needs until the new planes are ready to take over.

BBC: Watchdog warns of defence project delays and overspending