作　　者： ; ;

机构地区： 北京航空航天大学交通科学与工程学院土木工程系

出　　处： 《建筑结构学报》 2009年第S2期292-297,共6页

摘　　要： 在役混凝土结构的耐久性衰减是在环境和外荷载同时作用下发生,为了研究环境与荷载耦合作用下钢筋混凝土偏心受压构件的承载力、刚度和裂缝开展规律,探讨偏压构件的安全耐久性评估方法,采用环境模拟试验技术,对不同持载比例和不同环境作用下偏心受压柱进行了耐久性试验和承载力试验。试验结果表明,混凝土抗压强度降低和钢筋锈蚀是偏压柱承载力下降的主要原因;而持续荷载比例及环境作用对偏压柱体混凝土劣化和钢筋锈蚀率影响显著,因此对偏压柱承载力降低、刚度劣化、裂缝发展具有加速效应。柱的极限承载力随着持续荷载增加而降低,用侵蚀和冻融试验得到的混凝土抗压强度和锈蚀后钢筋的实际面积,以及现行混凝土结构设计规范计算公式计算钢筋混凝土偏心受压柱承载力,计算结果与试验结果吻合较好,为钢筋混凝土构件的抗力衰减评估和寿命预测提供了参考。 The durability degradation of reinforced concrete structures in-service occurs under the coupling action of environmental and sustained loading.The reinforced concrete eccentric compressive columns sustained different level loading were tested for the durability and bearing capacities,under the alternative actions of mix-aggressive and freeze-thaw circles,in order to investigate the degradation of columns mechanical properties,such as ultimate bearing capacity,stiffness and development of concrete cracks.The experimental results show that the deterioration of concrete mechanical properties and corrosion of longitudinal steels bars are the main reasons of bearing capacity decrease.The sustained loading level and environmental action have significant influence on the deterioration of concrete compressive strength and corrosion speed of steel bars,which accelerate deterioration of bearing capacity,stiffness and cracking development of the columns.The ultimate bearing capacities of the columns would be reduced as the sustained loading level increasing.Base on the experimental data of concrete compressive strength and real area of steel bars(after rusting),as well as current design code of concrete structures,the bearing capacity of reinforced concrete eccentric compressive columns were calculated.The calculating results correspond well with the experiments.These provide the references to appraise the resistance degradation of reinforced concrete columns and to predict the service life of structures.

关 键 词： 钢筋混凝土柱 侵蚀环境 冻融循环 持续荷载 偏心受压承载力

领　　域： [建筑科学]