恒定荷载对海工高性能混凝土抗氯离子渗透性能的影响  

Influence of constant load on resistance to chloride permeability of high performance concrete

作　　者：黎鹏平[1] 熊建波[1,2] 王胜年[1] 

机构地区：[1]中交四航工程研究院有限公司,水工构造物耐久性技术交通行业重点实验室,广东广州510230 [2]华南理工大学材料科学与工程学院,广东广州510640

出　　处：《水运工程》2015年第3期93-98,共6页Port & Waterway Engineering

基　　金：交通运输部交通运输建设科技项目(201132849A1140);国家科技支撑计划资助项目(2011BAG07B04);科技部专项资金项目(2013EG124049)

摘　　要：通常混凝土构件均处于受力状态,而对自由状态的混凝土试件开展耐久性研究很难真实地反映出混凝土构件的耐久性状况。本研究采用施加恒定压荷载和弯曲荷载的方式,研究荷载对混凝土抗氯离子渗透性能的影响。结果表明:混凝土试件纯受弯段的氯离子浓度随弯曲应力水平的提高而增大,且混凝土内的氯离子渗透深度随应力水平的增加而增大。试件距暴露面相同深度处的氯离子浓度随着压应力水平的提高先减少后增大。混凝土试件的氯离子扩散系数随压应力水平提高而先减少后增大,压应力水平较低时可提高混凝土的抗氯离子渗透性能。对于典型的海洋工程高性能混凝土配合比,混凝土试件的弯曲应力与其恒定荷载影响因子之间呈近似指数函数关系,在混凝土结构耐久性设计中应考虑弯曲荷载对氯离子扩散系数的影响。Generally, concrete structures are under various stress state, but it is difficult to reflect the concrete structures durability in lab tests, which is often researched by the free-state concrete specimens. This paper probes into the influence of constant compressive load and flexural load on resisting chloride penetration in marine concrete by changing the load levels. The results show that both the chloride concentration among the pure bending section in concrete at a given depth and the chloride penetration depth in concretes increase with the increasing flexural load level. But the chloride concentration in concrete at a given depth and the chloride diffusion coefficient of concrete decrease first and then increase with the increasing compressive load. It can improve the anti-penetration of chloride for concrete when increasing compressive load at low level. Furthermore, there is a significant correlation between the flexural load levels and the constant load factor when expressed as an exponential function for typical highperformance concrete mix. The influences of flexural loads on chloride diffusion coefficient shall be considered in durability design of concrete structures.

关 键 词：恒定荷载 高性能混凝土 氯离子浓度 氯离子扩散系数 

分 类 号：TU528[建筑科学—建筑技术科学]