Concrete cone failure of post installed fasteners during fire

Abstract

The fire resistance of fasteners needs to be verified for all failure modes applicable at ambient conditions. Generally, in most cases, for unprotected fasteners loaded in tension, steel failure mode is decisive. But for fasteners made of stainless steel and/or larger (bolt) sizes, concrete cone failure may be the decisive failure mode for small anchorage depths. Due to practical difficulties associated with loading an anchor during a fire test, very limited experimental data is available in literature and that to for relatively small embedment depths. The paper presents the results (6 nos) of the fire tests conducted on expansion anchors (made of stainless steel) with sizes M12 (hef = 70 mm) and M20 (hef = 100 mm). Moreover, the paper also compares the reduction in the concrete cone capacity with exposure duration, predicted as per the current design guidelines and the new set of experimental data obtained in this study.