A series of large compartment fire tests was performed to investigate the behavior and fire-induced failure mechanisms of full-scale composite floor assemblies with a two-story steel gravity frame, two bays by three bays in plan. A total of three 9.1 m à 6.1 m composite floor specimens with varying slab reinforcement and fire protection schemes for the secondary beam were tested under combined mechanical loads and compartment fire exposure. The first experiment (Test #1) was designed to achieve a 2-hour fire resistance rating per current U.S. practice and create baseline data for the behavior of the building. Test #1 specimen had the minimum specified reinforcement permitted in the U.S. for the composite slabs with profiled steel decks. Test #2 was conducted to study the effect of enhanced slab reinforcement with larger area and ductility on the fire resilience of the composite floor systems. Test #3 was conducted to study the effect of enhanced slab reinforcement as well as unprotected secondary beams on the fire resilience of the composite floor systems. Similar to Test #2, the floor slab in the test bay was reinforced with 9.5 mm diameter deformed bars with a center-to-center spacing of 30 cm. Unlike in Test #1 and Test #2, the secondary beam and its end connections in the test bay were left unprotected in Test #3.
Experiment Name Sort descending | Plot of Heat Release Rate | Ignition Photo | Date/Time | Specimen | Fuel Type | Test Duration (min) | Total Heat Released (MJ) | Peak HRR (kW) |
---|---|---|---|---|---|---|---|---|
15minRamp_R1 | ![]() |
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Four square burners | Natural Gas | 16.22
|
5,047
|
8,034
|
|
15minRamp_R2 | ![]() |
![]() |
Four square burners | Natural Gas | 20.00
|
4,850
|
7,980
|
|
60minRamp_R1 | ![]() |
![]() |
Four square burners | Natural Gas | 76.48
|
37,631
|
10,317
|
|
CompositeFloorTest_No1 | ![]() |
![]() |
Four square burners | Natural Gas | 107.33
|
63,542
|
11,496
|
|
CompositeFloorTest_No2 | ![]() |
![]() |
Four square burners | Natural Gas | 160.43
|
86,908
|
12,776
|
|
CompositeFloorTest_No3 | ![]() |
![]() |
Four square burners | Natural Gas | 145.28
|
90,480
|
12,124
|
Bryant, R. and Bundy, M. The NIST 20 MW Calorimetry Measurement System for Large-Fire Research, Technical Note (NIST TN) 2077, 2019
https://doi.org/10.6028/NIST.TN.2077
NIST Fire Calorimetry Database (FCD)
https://doi.org/10.18434/mds2-2314