Steel structure reinforced by the external prestressed CFRP bar is a new technology

the fire-resistance of reinforced steel structure is important.Based on the analysis of high temperature mechanical properties CFRP bar and combined with numerical calculation method for the transient dynamics

the fire resistance analysis numerical model was set up for large spacial steel portal frame with pre-stressed CFRP bar.The fire resistance effected by CFRP tendons and the linear expansion coefficient and the cross-sectional area of CFRP bar was analysed.The results show that:1 the ability to resist fire for large spacial steel portal frame after reinforcement by external prestressed CFRP bar is obviously improved;2the influence of CFRP linear expansion coefficient may be regardless;3 CFRP tendons prestressed design value and the cross-sectional area of prestressed steel structure fire resistance has a different degree of influence.