轴拉疲劳荷载下损伤混凝土氧气传输性能  

Oxygen diffusion property of damaged concrete under axial tension fatigue loads

作　　者：蒋志律 付传清[1] 严文杰 JIANG Zhilü;FU Chuanqing;YAN wenjie(School of Civil Engineering,Zhejiang University of Technology,Hangzhou 310014,China)

机构地区：[1]浙江工业大学土木工程学院,浙江杭州310014

出　　处：《西安建筑科技大学学报（自然科学版）》2023年第4期540-545,共6页Journal of Xi'an University of Architecture & Technology(Natural Science Edition)

基　　金：浙江省自然科学基金项目(LZ20E080003,LR21E080002);国家自然科学基金(51978620,52178232)。

摘　　要：氧气作为侵蚀介质参与钢筋混凝土结构的锈蚀破坏过程,因此,氧气扩散系数是结构耐久性预测模型的必要参数.针对实际服役中的混凝土结构,研究疲劳损伤混凝土氧气扩散系数与损伤变量的关系.研究结果表明:随着混凝土疲劳损伤度增加,小孔径孔隙比例先增后减;混凝土氧气扩散系数随着损伤度增大而增大,损伤度较大时增长速率较快;结合多孔材料气体扩散理论,建立了混凝土氧气扩散系数与损伤度、初始孔隙率的关系式,为海洋环境下混凝土结构耐久性预测提供理论基础.Oxygen is involved in the corrosion failure process of reinforced concrete structures as an erosion medium,so the oxygen diffusion coefficient is a necessary parameter for the prediction model of structural durability.In this paper,the relationship between oxygen diffusion coefficient and damage variable of fatigue damage concrete is studied for concrete structure in actual service.The results show that with the increase of fatigue damage degree of concrete,the proportion of small pore size increases first and then decreases.The oxygen diffusivity of concrete increases with the increase of damage degree,and the growth rate is larger at a greater damage degree.Based on the gas diffusion theory of porous materials,the function for oxygen diffusivity is established using damage degree and initial porosity,which provides a theoretical basis for predicting the durability of concrete structures in marine environment.

关 键 词：疲劳损伤 氧气扩散 核磁共振 混凝土 

分 类 号：TU375[建筑科学—结构工程]