FIRE PERFORMANCE OF MIXED STRUCTURES COMPOSED OF REINFORCED CONCRETE COLUMNS AND STEEL BEAMS

Mixed structures composed of reinforced concrete columns and steel beams can realize larger building spaces, whereas reinforced concrete columns are subjected to thermal stresses due to thermal elongation of long span steel beams in case of fire. It is very important to clarify the load carrying capacity of the complicated beam-column connections in fire. This paper presents the results of the sub-frame fire tests of a mixed structure composed of up-and-down RC column, steel beam and the connection. The test results indicate the non-fire-protected connection covered with thin steel plate has load carrying capacity during 3 hours of standard fire temperature curve. In this paper, fire performance of the beam-column connections is discussed.