FIRE resistance is a major part of the Arup study and the report raises major questions about steel's performance. It states: 'All steels lose strength with increasing temperature.
Passive fire protection systems designed for cellulosic fires have mostly not been tested for the more extreme hydrocarbon fires. There are considerable doubts that many of them would perform satisfactorily. Even products designed to serve in hydrocarbon fires will not all have been comprehensively tested for impact or mechanical damage conditions.'
OTHER R ECOMMENDATIONS n Concrete fire resistance: Improved with the use of polypropylene fibres. Augment concrete mix in core with steel fibres.
Biochemical attack: A four level method for designing and protecting against attack.
Evacuation: Improved design of escape routes including reinforced concrete core or blast and impact resistant board on steel core.
One route from all parts of building.
Alternative escape routes: outright rejection of parachutes and abseiling.