【作者】 李思琪； 刁波； 吴洁琼；

【Author】 Li Si-qi;Diao Bo;Wu Jie-qiong;Department of Civil Engineering,Beihang University;

【机构】 北京航空航天大学土木工程系；

【摘要】 沿海地区服役钢筋混凝土结构会受到疲劳荷载和氯侵蚀的综合作用,其疲劳性能劣化规律尚不清楚。本文模拟桥梁结构的实际工作状态,试验研究低应力水平对应的疲劳荷载上限为0.2Pu、0.3Pu、0.4Pu(Pu为RC梁静力极限荷载)且疲劳加载80万次产生初始疲劳损伤,再经历180天海水干湿循环,最后测定梁的剩余疲劳性能。试验结果表明:初始疲劳损伤后经历海水干湿循环的RC梁试件,其剩余疲劳寿命随荷载上限的增大而降低,当荷载上限为0.4Pu时,其疲劳寿命比0.3Pu下降37.7%;疲劳损伤与氯腐蚀综合作用后,在RC梁疲劳加载过程中,混凝土拉压应变、跨中挠度和裂缝宽度随荷载上限增加而非线性增大;RC梁正截面应变分布基本符合平截面假定。更多还原

【Abstract】 Reinforced concrete in service in coastal areas is comprehensively effected by fatigue load and chloride ion erosion.The fatigue deterioration law is still unclear.In order to emulate the actual working status of bridges,in this experiment,the research is made on RC beam with the upper limit of fatigue load of 0.2 Pu,0.3 Puand 0.4 Pu(Pu is static limit load of the RC beam),respectively under low stress level,experiencing dry-wet cycle of sea water for 180 days after 800 thousand times of fatigue load,and ultimately,its fatigue performance is measured.The experiment result shows:for the RC beam specimen experiencing dry-wet cycle of sea water after fatigue damage,with the increase of the upper limit of fatigue load,its fatigue life is reduced.When the upper limit of load is 0.4 Pu,the fatigue life is reduced by 37.7% compared with 0.3 Pu.During RC beam fatigue loading,tension-compression strain and mid-span deflection as well as the crack width is increased nonlinearly;The strain distribution of the RC beam in the normal section basically conforms to the flat section assumption.更多还原