Experimental study on fire resistance of a full-scale composite floor assembly in a two-story steel framed building

PurposeThe purpose of this paper is to report the first of four planned fire experiments on the 9.1 × 6.1 m steel composite floor assembly as part of the two-story steel framed building constructed at the National Fire Research Laboratory.Design/methodology/approachThe fire experiment was aimed to quantify the fire resistance and behavior of full-scale steel–concrete composite floor systems commonly built in the USA. The test floor assembly, designed and constructed for the 2-h fire resistance rating, was tested to failure under a natural gas fueled compartment fire and simultaneously applied mechanical loads.FindingsAlthough the protected steel beams and girders achieved matching or superior performance compared to the prescribed limits of temperatures and displacements used in standard fire testing, the composite slab developed a central breach approximately at a half of the specified rating period. A minimum area of the shrinkage reinforcement (60 mm2/m) currently permitted in the US construction practice may be insufficient to maintain structural integrity of a full-scale composite floor system under the 2-h standard fire exposure.Originality/valueThis work was the first-of-kind fire experiment conducted in the USA to study the full system-level structural performance of a composite floor system subjected to compartment fire using natural gas as fuel to mimic a standard fire environment.

Experimental Study of Microwave Attenuation in a Compartment Fire

In this letter, we show the experimental results of microwave attenuation characteristics for representative communication frequencies (UHF, public safety long-term evolution [PSLTE], LoRa, Wi-Fi, and LTE) in a compartment fire. We used kerosene, lumber, and urethane foam as fuels, which can be easily found in homes, and measured the signal intensity with three antenna heights to investigate the effect of the flame and smoke. In the compartment environment, the ionized particles were the dominant attenuation factor of the signals. Furthermore, measurements revealed that the attenuation depends on frequencies and fuel types. In particular, large attenuation was observed at particular frequencies when burning lumber and urethane foam.