ESTIMATION OF TEMPERATURE PROFILE, STRESS PROFILE, AND STRENGTH OF STEEL BAR - TIMBER COMPOSITE BEAM ON 60-MINUTE FIRE RESISTANCE TESTS

Abstract

To verify strengths of steel bar-timber composite beam after the 60-minute burning test reported in a previous paper, a method is proposed to estimate temperature profile in uncharred area inside the beam using temperature-burning time curves within each specimen to be measured, and calculations for bending and shearing stress within the beams are conducted using by the existing reduction rate of elastic modulus and strength of timber as temperature increases. The relationship between stress profile in timber expected in the calculation of strength of the beam according to the proposed design method and those under the burning test is clarified.