Temperature distribution of trapezoidal sheeting in fire

Trapezoidal sheeting has been used for stabilizing steel members for a long time. In recent years several documents which include the comprehensive theoretical background and design guidelines for practice have been published. ECCS published the design recommendations including an example of considerable cost savings in steel constructions when sheeting is used for stabilization. However, these documents did not cover the fire limit state. The study presented in this paper is aimed at stabilization of steel members through the trapezoidal sheeting in fire. The papers describes four full-scale fire tests carried out on a horizontal furnace for fire resistance testing. The test specimens were assembled from a fire protected steel beam and trapezoidal sheeting. The profile of the steel beam was a HEA 160 (S355) in two of the tests, and a RHS 150x150x8 (S420) in the remaining tests. Two different profiles of the trapezoidal sheeting were used during the tests. Experimental testing was conducted to determine the temperature fields in trapezoidal sheeting and in the supporting structural steel sections as well as in the connectors with special attention given to the temperatures at the joint above the steel beam section. The results of the tests show that at the failure of the specimens the screw temperatures were between 720°C and 780°C. The screw temperatures were lower than the temperature of trapezoidal sheets but higher than the temperatures of the top flanges of fire protected steel beam. The results of the tests provided experimental data for the critical variables related to building
stabilization in fire through the cladding systems which is under investigation of RFCS project STABFI.