OUT-OF-PLANE FAILURE OF RC BEARING WALLS SUBJECTED TO ONE-SIDED FIRE EXPOSURE: AN EXPERIMENTAL INVESTIGATION

摘要

This paper describes a full-scale experimental investigation on the out-of-plane thermo-mechanical behavior of two planar reinforced concrete (RC) bearing wall specimens under fire.The wall specimens were heated on one surface over half of the wall height through the ASTM El l9 standard fire time-temperature curve, while simultaneously being subjected to a constant axial load at the top.The walls were fixed at the base and free to displace vertically and rotate at the top.In the out-of-plane lateral direction, the top of each wall was restrained, representing a rigid floor slab.The test results show that the out-of-plane lateral strength and stability of RC bearing walls under service-level gravity loads can be severely compromised by the unsymmetrical deterioration of concrete and reinforcing steel over the wall thickness, as well as the development of significant out-of-plane moments and shear forces from restrained thermal bowing.For the walls described in this paper, critical out-of-plane shear cracking and ultimate buckling failures were observed at fire durations significantly shorter than the durations from current prescriptive codes.