Demonstration of real fire tests in car parks and high buildings

Researches sponsored by ECSC have just demonstrated that, in case of fire in car parks or in high buildings, it is generally not necessary to insulate the steel section (beam and/or columns) to obtain a satisfactory safety level. These researches are based on some specific simple fire tests and on numerical simulations. In order to fully convince national authorities that these kinds of buildings don't need a large duration of fire resistance requirements, it was planned to carry out real fires in real unprotected steel buildings. These fires were performed in 3 different configurations: - a large (high) compartment with a local fire ; - an open car park with a fire scenario involving several cars ; - a closed car park with a fire scenario involving several cars. The preliminary and demonstration tests in the large compartment were performed in October 1998. A strong fire load composed of wood (1200 kg for the preliminary test and 2200 kg for the demonstration) was ignited in the large unprotected steel building. Due to the height of the building (14 m) and its large surface (about 9000 m 2 ), the temperature far from the fire source was very low, and the temperature above the source was not high enough to allow a sufficient deformation of the structure. The large-scale tests have shown that a strong localised fire in a large compartment is not able to lead to the collapse of the building. Comparisons of the test measurements with simple calculations methods developed in previous researches and advanced models in steady state have been shown leading to a good correlation. Additional works were made to improve the conclusions of the previous research concerning car parks. Statistics on the real fires in open and closed car parks have been obtained from the study of a large number of fire brigade interventions in car parks fires, mainly in Paris, but also in others big cities of Europe. These statistics lead to definition of scenarios of car fire for designing car park structures. Additional car fire tests under calorimetric hood were also made to improve and confirm the design fire corresponding of class-3 car fires. Regarding tests to be performed in open car parks, an open car park has been built in France. The dimensions of the open car park are 32 m long and 15 m large. The height of the ground level to the floor at the level 1 is 3.0 m. This type of car park leads to 48 parking bays (24 at each level). The structural behaviour of this car park has been verified before construction by fire engineering calculations using a predefined fire scenario and engineering tools developed during a previous ECCS research project concerning car parks. Three tests have been performed. The first test was a preliminary test performed the 26 September 2000. Three cars were involved in the fire. The second performed the 25 October 2000 was a similar test - fire involving three cars. The second test was the demonstration test performed in front of 250 people (fire brigade, ministry, and industries, from Europe). A third test was performed the 8 November 2000 for assessing the fire propagation from one car to another parked in front of. Two additional tests of a single car fire have been performed under calorimeter hood to characterise the fire development of the type of the cars used in the open car park.