摘要
为得出受弯混凝土构件内随截面应力变化的氯离子传输规律,首先分析了受弯混凝土构件内不同深度的应力分布,在据此得出相应位置的孔隙率变化后,依据氯离子扩散系数和孔隙率之间的变化关系得出了不同应力水平下各深度处的氯离子扩散系数计算模型。利用此模型分别计算了素混凝土和钢筋混凝土构件内氯离子侵蚀试验的相关数据,得出了相应的氯离子扩散系数,其值与试验所得的氯离子扩散系数较为接近。基于此模型的分析结果表明:在受弯混凝土梁内,从受压表面开始,氯离子扩散系数随深度的增加而增大,但增加程度较小,增幅在3%左右;随着荷载水平的增大,混凝土受拉区的氯离子扩散系数逐渐增大,受压区的氯离子扩散系数逐渐减小。本文所得结果可为氯盐环境中受弯混凝土构件的耐久性设计提供参考。
To obtain the transmission character of chloride ion under different levels of stress in the concrete section,the stresses at different depths of concrete subjected to bending load were analyzed firstly.Then,porosity at the corresponding position in concrete was assessed.Finally,chloride diffusion coefficient in the concrete section,which influenced by bending load was obtained according to the relationship between chloride diffusion coefficient and porosity.Two sets of exist experiments of plain and reinforced concrete members were used to calculate the theoretical chloride diffusion coefficients.The results agreed well to the test data respectively.Calculated results also show that chloride diffusion coefficient increases slightly (about3%) as the depth of concrete from the compression surface of the flexural beam.The chloride diffusion coefficients increases in tensile zone,but reduces in the compression zone with bending load increases.These results can help durability design of bending concrete specimen serving in chloride environment.
作者
陈玉杰
延永东
刘荣桂
戴丽
CHEN Yujie;YAN Yongdong;LIU Ronggui;DAI Li(Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang 212013,China;Nantong Institute of Technology,Nantong Key Laboratory of Building Structure,Nantong 226001,China)
出处
《四川建筑科学研究》
2019年第3期27-31,共5页
Sichuan Building Science
基金
国家自然科学基金(51608233,51778272)
南通市建筑结构重点实验室项目(CP12015005)
关键词
混凝土
弯曲荷载
氯离子扩散系数
应力分布
concrete
bending load
chloride diffusion coefficient
stress distribution
