一般大气环境下钢筋混凝土构件抗震性能时变特征

采用精细化有限元全过程分析方法,考虑混凝土碳化、钢筋锈蚀及其引起的粘结滑移性能退化等多因素耦合作用,研究在一般大气环境使用年限内,耐久性退化对构件抗震性能的影响规律和内在机理.结果表明,一般大气环境下,钢筋混凝土构件使用年限在30a内抗震性能变化不大.当使用年限超过30a后,抗震性能显著退化.当使用100a时,承载力降低22.5%,刚度约退化33.5%,延性降低36.7%,耗能能力降低40.5%.建议在一般大气环境下对钢筋混凝土构件进行抗震设计时,应考虑随使用年限的增长,耐久性退化对抗震性能的影响,从而保证结构良好的抗震性能.

Time-dependent Seismic Performance of Reinforced Concrete Member under Common Atmosphere Environment

Based on high-precision nonlinear finite element analysis, the multi-factor combined effects on reinforced concrete were considered, including concrete carbonation, reinforcement corrosion, and bond-slip performance degradation. And a refined finite element model was established to investigate the influence of durability deterioration on the seismic performance of reinforced concrete members in common atmosphere environment from corrosion rate of reinforcement and carbonation rate of concrete. It is revealed that ,when the service life was less than 30 years, the seismic performance of reinforced concrete members was changed little, while after 30 years, it degraded significantly. On the other hand, when the service life reached 100 years, concrete bearing capacity decreased to 22.5 %, stiffness decreased to 33.5 %, ductility decreased to 36.7 % and energy dissipation decreased to 40.5 %. To this end, it suggests that the influence of the service life and durability deterioration on seismic performance of the reinforced concrete members in common atmosphere environment should be considered in seismic design to guarantee the earthquake-resisting capacity of the structures.