小偏心钢筋混凝土受压柱卸载后的徐变后效研究

基于弹性徐变理论和线性叠加原理,研究了对称配筋的钢筋混凝土偏心受压柱中,钢筋和混凝土的应力-应变增量关系和递推公式;并且通过数值方法计算了考虑加、卸载后钢筋和混凝土应力-应变的变化过程;同时,分析了偏心距、配筋率、加载龄期及卸载时间等因素对长期荷载下钢筋混凝土偏心受压柱徐变特性和卸载后混凝土应力的影响规律.研究成果可为长期荷载下钢筋混凝土偏心受压构件的设计提供参考.

Creep analysis of RC eccentric compression columns

The creep of concrete have significant impact in the mechanical properties of the entire reinforced concrete structure in the long-term loads.Current design methods of reinforced concrete structure mainly aim at the direct effects of the loads,and ignore the indirect effects of creep.Based on the elastic-creep theory,this paper analyzes the relationship of stress-strain increment and recurrence formula of reinforcement and concrete in RC eccentric compression columns.The stress-strain changing process considering repeated loading is also calculated through numerical method.The effects of long-time loading on creep behavior of RC eccentric compression columns and concrete stress after unloading are studied.Many factors are then considered in the studies,that include the eccentricity,the reinforcement ratio,the age of concrete at loading,and the duration of loading.The results can provide references for the design of reinforced concrete eccentric compression members in the long-term loads.