EVALUATION OF BOLT AXIAL TENSION FORCE AND SLIP STRENGTH FOR HIGH-STRENGTH BOLTED CONNECTIONS AFTER HEATING AND COOLING PROCESSES

Abstract

In this study, bolt axial tension force and slip strength for high-strength bolted connections after heating and cooling processes were investigated by using an ultrasonic measuring unit and the tensile tests of the connection specimens, respectively. The measuring results on axial tension force of JIS F10T and slip strength of the connection subjected to the heat-damages were accumulated, it was, furthermore, clarified that the secondary tightening for the damaged connections was an effective repair work to recover the bolt axial tension force and the slip strength after fires.