中文摘要：

为研究不同持续荷载比例（持续偏压荷载占极限偏压荷载的比例）和不同环境对RC（reinforced concrete）柱的滞回性能和氯质量分数影响,试验室模拟了沿海地区RC结构的工作条件.持续荷载比例分别为0、0.2和0.35的RC柱试件,经历100次海水干湿循环或置于大气环境100 d后,进行低周水平反复加载试验并测试受拉区混凝土的氯离子质量分数.结果表明,持续偏压荷载使海水干湿循环柱和大气环境柱的滞回曲线均呈现明显的不对称性,且前者的不对称性甚于后者.当水平荷载产生的截面应力分布与持续偏压荷载的同向且持续荷载比例为0.35时,海水干湿循环柱的峰值荷载和耗能能力分别是大气环境柱的0.89和0.57倍;反之,前者分别是后者的1.04和1.08倍.持续偏压荷载耦合海水干湿循环作用后,距受拉表面20 mm和40 mm深处,受拉混凝土的氯离子质量分数均是持续偏压荷载单独作用（即大气环境柱）的3倍以上.可见,持续偏压荷载耦合海水干湿循环作用加速了氯离子的渗透和滞回性能的劣化.

英文摘要：

To investigate the impact of different sustained load ratios （the ratio of sustained eccentric compressive load to ultimate eccentric compressive load） and different environments on hysteretic behavior and chloride mass fraction of RC （reinforced concrete） columns, the working conditions of RC structures in coastal region were simulated in laboratory. The sustained load ratios were 0, 0.2 and 0.35, respectively. After the RC columns with sustained load had undergone 100 cycles of seawater dry-wet or 100 days in atmospheric environment, low cyclic horizontal loading test was conducted and chloride mass fraction in tensile concrete was tested. Results show that sustained eccentric compressive load lead to the apparent asymmetric pattern of the hysteretic curves of RC columns in seawater dry-wet environment or in atmospheric environment. And the asymmetric pattern of former is more apparent than that of latter. While the stress distribution of cross-section under horizontal cyclic loading is the same as that of sustained eccentric compressive load and the sustained load ratio is 0.35, the peak load and the energy dissipation of RC columns in seawater dry-wet environment are 0.89 and 0.57 times of that in atmospheric environment, respectively. But the former are 1.04 and 1.08 times of the latter if reverse cyclic load is applied. In the depth of 20 mm and 40 mm from tensile surface, chloride mass fraction of tensile concrete in the columns subjected the coupled actions of sustained load and seawater dry-wet cycles are more than 3 times of that only subjected to sustained load （the RC columns in atmospheric environment）. These clearly imply that the coupled action of sustained eccentric Compressive load and seawater dry-wet cycles could facilitate the chloride penetration and hysteretic behavior degradation.