Current provisions in codes and standards evaluate the fire behavior of reinforced concrete（RC） structure based on the isolated structural members

i.e.slabs

beams and columns

without considering the effects of end restraints on the fire behavior.However

previous fire tests and actual fire incidents have shown that the fire behavior of structural members is obviously different from that of isolated members

due to the adjoining structural member restraint.The CFS-strengthened RC beams with elastic axial and rotational restraints at beam ends are selected for numerical parametric study

and the effects of some parameters（i.e.

axial/rotational restraint ratio

section dimensions

length

load ratio

strengthening ratio

reinforcement ratio

thickness of concrete cover

and thickness of fire insulation） on the bending moment at the ends of the restrained RC beams exposed to ISO834 standard fire are analyzed.Based on the extensive simulation results

a practical calculation method for the bending moment at the ends of the restrained beams subjected to fire is proposed.It can be found that:（1） the bending moment at the ends of the restrained beams increases gradually first and then changes gently;and（2） the bending moment at the ends of the restrained beams strengthened with CFS and with fire insulation is quite different from that without fire insulation

even in the case that the thickness of the fire insulation is only 10 mm.