Fire Resistance of Hybrid Floor Based on Small-Scale Furnace Tests and Energy-Based Time Equivalent Approach

A novel hybrid floor, which was a prefabricated composite system infilled using polymers with hollow cores between its top and bottom steel plates, was previously developed for application in steel structures. In addition, the structural performance of the steel floor, including its bending capacity, floor vibration, and dynamic characteristics, were investigated. However, as the fire resistance performance of the hybrid floor had not been investigated, it was installed in actual buildings using insulating materials, which caused problems, such as a dirty workplace and additional work that prolonged the construction period. In this study, small-scale furnace tests, whose specimens have fewer variables in comparison with those of full-scale tests, were conducted instead of full-scale furnace tests to analyze the effects of various variables on the fire resistance performance of the hybrid floor. In fact, the heating curves obtained via the small-scale furnace tests were not similar those suggested by Korean Standards (KS). The energy-based time equivalent approach was applied to calibrate the results. Thus, the fire resistance ratings were estimated based on small-scale furnace tests via the energy-based time equivalent approach with respect to polymer thickness and aspect ratio, which were expressed using the lengths and widths of the specimens.