Ultimate strength performance of plasterboard lined steel stud walls under fire conditions

Abstract

In this research, a series of 12 full scale fire tests of plasterboard lined steel stud walls were undertaken. The steel stud wall systems were made of 1.15 mm G500 grade steel and 16 mm fire resistant plasterboards. If increased fire rating is required, it is common practice to add more layers of plasterboard and/or use cavity insulation. However, in this test series a new composite unit comprising of two plasterboards with a thin insulationlayer between them was also used on each side of the steel frame. This was expected to give a higher fire resistance rating. Our tests have shown that the fire limit state was always corresponds to the collapse of steel studs (stability criterion). The studs could not support the appliedloads as theirmechanical propertiesdeteriorated withincreasing fire exposure while the thermal effects and associated deformations and stresses intensified. This paper presents the details of the full scale fire tests of LSF wall systems and the results. It discussesin detail the failure of studs and associated thermal and structural interactions that determine the fire limit state of LSF stud wall systems. Simple design rules are proposed, which can be used to predict the ultimate strength of LSF stud wall systems under fire conditions.