Postearthquake Fire Performance of Sprayed Fire-Resistive Material on Steel Moment Frames

Abstract

This paper describes damage patterns in sprayed fire resistive material (SFRM) on steel moment frame beam-column assemblages owing to a strong seismic event, and the thermal consequences of this damage when exposed to postearthquake fire. Large-scale experimental tests were performed to examine the bond of SFRM to steel in the three-dimensional configuration of a moment frame beam-column connection region. Two beam-column assemblages treated with SFRM were subject to quasi-static cyclic loading, resulting in large deformations and plastic hinges in the beam and local damage to the SFRM on the beam. Heat transfer finite-element analyses were performed to compare beam-column connections with damaged SFRM and fully insulated connections (with no damage) under the action of both standard and natural fires. Results of the heat transfer analyses show that SFRM damage on the beams adjacent to the column causes an increase in heat transferred into the column and elevated temperatures in the column. The elevated temperatures in the column cause important reductions in strength and stiffness of the steel.