Fire Safety Science Digital Archive

Composite sandwich walls of steel plates and concrete are considered to have possible applicability to main structures of nuclear power plants. This structure is fabricated by placing concrete between two steel plates with steel-studs, shear reinforcing bars and web plates in the wall in order to fasten the steel plates on both sides of the wall together and to connect the plates to concrete. It is considered that heat transfers from fire-exposed surface of the wall to unexposed surface through steel members which form heat-bridges in case of fire. To examine the heat transfer and temperature distribution in the walls with heat bridges, a heat transfer analysis was performed. Then, heating tats by using small scale models were carried out. The results obtained showed that after two hours of heating up to close to 1000°C (specified heating the temperature) on the fire-exposed wall surfaces, the maximum temperatures on the other side of the wall surfaces of 20cm thick specimens were about 100"C, which were much lower than the ignition temperature of wood, 260°C. The temperature within 73 % of the total cross sectional m a of the walls did not exceed 400 "C.