Recommendations for Improving Fire Performance of Steel Bridge Girders

University Transportation Centers Program2018PDFTech ReportWhitney, ReevesBraxton, Nicole LeoAlsayed, HalimaManhattan College. Department of Civil and Environmental EngineeringUnited States. Department of Transportation. University Transportation Centers Program (UTC)United States. Department of Transportation. University Transportation Centers (UTC) ProgramCity University of New York. University Transportation Research CenterUniversity Transportation Research CenterNew York (New York)United StatesGirder bridgesSteel bridgesFire resistancesteel bridge girdersfire protection49198-19-28Infrastructure risk due to fire has been well documented. In particular, bridges in the urban environment are susceptible due to low overhead clearances on overpasses, existing simple spans with no redundancy, due to low overhead clearances on overpasses, existing simple spans with no redundancy, narrow lane widths and general alignment congestion. Although the risk is significant, the current AASHTO Bridge Design Specification does not include provisions for design due to fire conditions. As such, this paper considers alternatives for improving the fire resistance of steel bridges using both traditional and nontraditional fire protection methods. In this paper, a total of eight parameters are investigated: (1) global section factor (W/D ratio) of bridge girder cross-section; (2) thickness of the flange; (3) thickness of the web; (4) steel material specification; (5) concrete slab width; (6) concrete slab thickness; (7) thickness of intumescent paint; and (8) thickness of SFRM. It is shown that the temperature domain performance can be significantly increased by (1), (3), (7), and (8) while the other parameters are less effective. The recommendations from this research can be readily implemented in both bridge design and retrofit scenarios.125