Behavior of Prestressed Tension Steel Members Exposed to Fire

Abstract

This paper presents results from fire resistance tests on three prestressed steel tension members. The test variables included degree of prestress and load level. During the tests, axial deformation, temperature, tensile force and failure times are recorded in the prestressed tension steel members. Data from fire tests indicate that during initial stages of fire, the magnitude of tension in the cable strands increases with temperature. Further increase in strand temperature leads to decrease in tension in cable strands resulting from degradation of strength and elastic modules of steel and ultimately approaching zero just prior to failure. Results from these tests indicate that load level has a significant influence on the response of fire exposed prestressed tension steel members, with higher load level leading to lower fire resistance. In addition, the temperature of failure is governed from the level of prestress in prestressed tension steel members, with higher degree of prestress leading to higher failure temperature