Contemporary events have shown that buildings designed to modern day codes need to be able to resist accidental extreme actions such as impact, explosions, weather, chemical and seismic events. This is one of the reasons for the present reviewing of the Eurocodes used to design concrete structures. The definition of the use of concrete used in extreme environments is difficult, but extreme events are usually defined as those rare events which occur at the extreme ends of the statistical distribution in a particular situation. Often the clients who order the concrete structures are unable to determine the extremes of environments the concrete will encounter and rely on the designers and construction companies to be able to predict the service conditions.