Thermal analysis of GFRP-reinforced continuous concrete decks subjected to top fire

This paper presents a numerical study that investigates the behavior of continuous concrete decks doubly reinforced with top and bottom glass fiber reinforced polymer (GFRP) bars subjected to top surface fire. A finite element (FE) model is developed and a detailed transient thermal analysis is performed on a continuous concrete bridge deck under the effect of various fire curves. A parametric study is performed to examine the top cover thickness and the critical fire exposure curve needed to fully degrade the top GFRP bars while achieving certain fire ratings for the deck considered. Accordingly, design tables are prepared for each fire curve to guide the engineer to properly size the top concrete cover and maintain the temperature in the GFRP bars below critical design values in order to control the full top GFRP degradation. It is notable to indicate that degradation of top GFRP bars do not pose a collapse hazard but rather a serviceability concern since cracks in the negative moment region widen resulting in simply supported spans.

[1]  S. Esterby.  American Society for Testing and Materials , 2006 .

[2]  Emidio Nigro,et al.  Fire resistance of concrete slabs reinforced with FRP bars. Part I: Experimental investigations on the mechanical behavior , 2011 .

[3]  M. Z. Naser,et al.  Thermal-Stress Finite Element Analysis of CFRP Strengthened Concrete Beam Exposed to Top Surface Fire Loading , 2011 .

[4]  M. Z. Naser,et al.  Thermal-stress analysis of RC beams reinforced with GFRP bars , 2012 .

[5]  Paul J. Hogg,et al.  Fire testing of concrete beams with fibre reinforced plastic rebar , 2006 .

[6]  Mark F. Green,et al.  Fire insulation schemes for FRP-strengthened concrete slabs , 2006 .

[7]  M. Z. Naser,et al.  Modeling of insulated CFRP-strengthened reinforced concrete T-beam exposed to fire , 2009 .

[8]  M. Z. Naser,et al.  Performance of RC T-Beams Externally Strengthened with CFRP Laminates under Elevated Temperatures , 2014 .

[9]  M. Z. Naser,et al.  Modeling Fire Response of RC Beams Strengthened with CFRP Laminates , 2015 .

[10]  K. Tan,et al.  Performance of FRP-Strengthened Beams Subjected to Elevated Temperatures , 2011 .

[11]  Emidio Nigro,et al.  Performances at high temperature of RC bridge decks strengthened with EBR-FRP , 2015 .

[12]  Emidio Nigro,et al.  Fire resistance of concrete slabs reinforced with FRP bars. Part II: Experimental results and numerical simulations on the thermal field , 2011 .

[13]  Luc Taerwe,et al.  Properties of Fiber Reinforced Plastics at Elevated Temperatures with Regard to Fire Resistance of Reinforced Concrete Members , 1999, SP-188: 4th Intl Symposium - Fiber Reinforced Polymer Reinforcement for Reinforced Concrete Structures.

[14]  Venkatesh Kodur,et al.  Factors governing the fire response of concrete beams reinforced with FRP rebars , 2013 .