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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 (230 mm2/m). Unlike in Test #1 and Test #2, the secondary beam and its end connections in the test bay were left unprotected in Test #3. The test floor was mechanically loaded to 2.7 kPa to mimic the code-prescribed gravity loads for fire conditions. The compartment test fire created upper-layer gas temperatures like those in standard fire resistance tests. A total of four natural gas burners distributed over the compartment floor created a peak gas temperature exceeding 1100 °C below the test floor. A wide transverse crack with flame leak above the floor developed at 132 min in the mid-panel region. The mid-panel vertical displacement reached 535 mm (equivalent to the ratio of L/17 where the span length L = 9.1 m) at 132 min. It reached a peak value of 655 mm (L/14) at 140 min, when the actuator loading was removed. The Test #3 showed that the use of deformed steel bars (230 mm2/m) for the slab reinforcement maintained the structural integrity of the tested slab longer than the specified rating period with an unprotected secondary beam. The experimental results presented in this report can be used for validation of predictive models to perform parametric studies incorporating the variability in the steel reinforcement scheme (area, spacing, and material) for safer and cost-effective composite floor construction for fire safety.
Video 1: Fire Resilience of a Steel-Concrete Composite Floor System: Full-Scale Experimental Evaluation for Influence of Slab Reinforcement and Unprotected Secondary Beam (Test #3)
This video shows a time-lapse of a structural-fire experiment conducted at the National Fire Research Laboratory (NFRL). The test structure is a two-story, two-bays by three-bays gravity frame with a story height of 3.3 m. The test bay (at the center of the building) measures 6.1 m by 9.1 m and is hydraulically loaded to service gravity loads. The fire is produced by natural gas-fueled burners with a total maximum capacity of 16 megawatts. A standard fire-resistance test time-temperature curve is used to generate a baseline data. For more information and other videos, please visit the project website. [no audio]
Video 2: Fire Resilience of a Steel-Concrete Composite Floor System: Full-Scale Experimental Evaluation for Influence of Slab Reinforcement and Unprotected Secondary Beam (Test #3) - Top of Slab Center View
This video shows a time-lapse of a structural-fire experiment conducted at the National Fire Research Laboratory (NFRL). The test structure is a two-story, two-bays by three-bays gravity frame with a story height of 3.3 m. The test bay (at the center of the building) measures 6.1 m by 9.1 m and is hydraulically loaded to service gravity loads. The fire is produced by natural gas-fueled burners with a total maximum capacity of 16 megawatts. A standard fire-resistance test time-temperature curve is used to generate a baseline data. For more information and other videos, please visit the project website. [no audio]
Video 3: Fire Resilience of a Steel-Concrete Composite Floor System: Full-Scale Experimental Evaluation for Influence of Slab Reinforcement and Unprotected Secondary Beam (Test #3) - Top of East Side Slab View
This video shows a time-lapse of a structural-fire experiment conducted at the National Fire Research Laboratory (NFRL). The test structure is a two-story, two-bays by three-bays gravity frame with a story height of 3.3 m. The test bay (at the center of the building) measures 6.1 m by 9.1 m and is hydraulically loaded to service gravity loads. The fire is produced by natural gas-fueled burners with a total maximum capacity of 16 megawatts. A standard fire-resistance test time-temperature curve is used to generate a baseline data. For more information and other videos, please visit the project website. [no audio]
Video 4: Fire Resilience of a Steel-Concrete Composite Floor System: Full-Scale Experimental Evaluation for Influence of Slab Reinforcement and Unprotected Secondary Beam (Test #3) - Top of West Side Slab View
This video shows a time-lapse of a structural-fire experiment conducted at the National Fire Research Laboratory (NFRL). The test structure is a two-story, two-bays by three-bays gravity frame with a story height of 3.3 m. The test bay (at the center of the building) measures 6.1 m by 9.1 m and is hydraulically loaded to service gravity loads. The fire is produced by natural gas-fueled burners with a total maximum capacity of 16 megawatts. A standard fire-resistance test time-temperature curve is used to generate a baseline data. For more information and other videos, please visit the project website. [no audio]
Video 5: Fire Resilience of a Steel-Concrete Composite Floor System: Full-Scale Experimental Evaluation for Influence of Slab Reinforcement and Unprotected Secondary Beam (Test #3) - Top of Slab East View
This video shows a time-lapse of a structural-fire experiment conducted at the National Fire Research Laboratory (NFRL). The test structure is a two-story, two-bays by three-bays gravity frame with a story height of 3.3 m. The test bay (at the center of the building) measures 6.1 m by 9.1 m and is hydraulically loaded to service gravity loads. The fire is produced by natural gas-fueled burners with a total maximum capacity of 16 megawatts. A standard fire-resistance test time-temperature curve is used to generate a baseline data. For more information and other videos, please visit the project website. [no audio]
Video 6: Fire Resilience of a Steel-Concrete Composite Floor System: Full-Scale Experimental Evaluation for Influence of Slab Reinforcement and Unprotected Secondary Beam (Test #3) – FLIR Camera - Top of Slab Center View
This video shows a time-lapse of a structural-fire experiment conducted at the National Fire Research Laboratory (NFRL). The test structure is a two-story, two-bays by three-bays gravity frame with a story height of 3.3 m. The test bay (at the center of the building) measures 6.1 m by 9.1 m and is hydraulically loaded to service gravity loads. The fire is produced by natural gas-fueled burners with a total maximum capacity of 16 megawatts. A standard fire-resistance test time-temperature curve is used to generate a baseline data. For more information and other videos, please visit the project website. [no audio]
Video 7: Fire Resilience of a Steel-Concrete Composite Floor System: Full-Scale Experimental Evaluation for Influence of Slab Reinforcement and Unprotected Secondary Beam (Test #3) - Interior Water Camera at East
This video shows a time-lapse of a structural-fire experiment conducted at the National Fire Research Laboratory (NFRL). The test structure is a two-story, two-bays by three-bays gravity frame with a story height of 3.3 m. The test bay (at the center of the building) measures 6.1 m by 9.1 m and is hydraulically loaded to service gravity loads. The fire is produced by natural gas-fueled burners with a total maximum capacity of 16 megawatts. A standard fire-resistance test time-temperature curve is used to generate a baseline data. For more information and other videos, please visit the project website. [no audio]
