The Department of Energy states that “In buildings constructed of SIPs, fire investigators have found that the panels held up well. For example, in one case where the structure exceeded 1,000°F (538°C) in the ceiling areas and 200°F (93°C) near the floors, most wall panels and much of the ceiling remained intact. An examination of the wall panels revealed that the foam core had neither melted nor delaminated from the skins.
Aslo See:
GFRC Fire Performance: http://www.gfrcconstruction.com/gfrc-fire-preformance/
GFRC Fire Test Video: http://www.gfrcconstruction.com/gfrc-fire-testing-video/